A GUIDE TO ENERGY EFFICIENT CONCEPTS
FOR NEW RESIDENTIAL CONSTRUCTION
Build Better
To request additional copies of this guide,
email [email protected].gov or call 1-866-NYSERDA.
ISBN #978-1-936842-06-3
I
Foreward
This guide was developed by the
New York State Energy Research and
Development Authority (NYSERDA) to
help builders construct homes that use
less energy. Rising energy costs is a
growing concern to homeowners and
communities. Energy efcient buildings
can signicantly reduce energy bills and
create quieter, more comfortable homes
with improved indoor air quality. Reducing
energy use also decreases the amount of
energy needed from power plants, lowers
greenhouse gas emissions, improves
air quality and helps New York State’s
economy by saving millions of dollars in
energy costs.
This guide is one small component of
NYSERDA’s mission to advance innovative
energy solutions in order to improve New
York State’s environment and economy.
It is intended to be an informative tool
used often by builders at the construction
site and homeowners who are actively
engaged in projects with energy
components.
II
Project Manager:
Marilyn Kaplan, NYSERDA
Assistant Project Manager:
Christopher Sgroi, NYSERDA
Program Manager:
Priscilla Richards, NYSERDA
Energy Efciency Services Director:
Todd Baldyga, Tom Barone, NYSERDA
Technical Assistance:
Daniel Farrell, Patrick Fitzgerald,
Gregory Pedrick, NYSERDA
Marketing and Graphic Assistance:
Mary Chick, Meaghan Mariany,
Diane Welch, Ben O’Brien, NYSERDA
Authors and Contributors:
Institute for Building Technology and
Safety: Michael DeWein, Christopher
Doyle, Keith Ortale, Art Pakatar,
Anthony Portillo
James Belluardo
Conservation Services Group:
Michael Burke, Mark Hutchins
Louis Marrongelli
NYS Department of State: Michael
Burnetter, Joseph Hill
Northeast Energy Efciency Partnerships:
Kevin Rose
Acknowledgments
NYSERDA, a public benefit corporation,
offers objective information and analysis,
innovative programs, technical expertise,
and support to help New Yorker’s increase
energy efficiency, save money, use
renewable energy, and reduce reliance on
fossil fuels. NYSERDA professionals
work to protect the environment and
create clean-energy jobs. NYSERDA
has been developing partnerships to
advance innovative energy solutions in
New York State since 1975. To learn more
about NYSERDA’s programs and funding
opportunities, visit nyserda.ny.gov or
follow us on Twitter, Facebook, YouTube,
or Instagram.
This guide was an effort of NYSERDA’s
Codes and Standards Program. This
program promotes best practices for
compliance with the State’s Energy
Code within the design, construction
and enforcement communities in order
to provide more energy efcient and
durable structures for the citizens of
New York State.
Special thanks to the following:
All images and illustrations courtesy of NYSERDA unless otherwise noted.
III
Background 1-8
How to Use this Guide ............................. 1
Energy Conservation:
A Whole Building Approach
..................... 1
Building Quality and Durability
................. 2
New York State
Code Requirements
................................. 2
NYSERDA Support................................... 3
ENERGY STAR
®
and
More Restrictive Local Standards
............ 3
High Performance Buildings and
Renewable Energy
.................................... 4
Working with Architects
and Engineers
........................................... 5
Inspections and
Performance Testing
................................ 5
Building Commissioning
and Maintenance
...................................... 6
Owner’s Manual and
Homeowner Education
............................. 6
Occupant Safety
....................................... 7
Further Reading and
Additional Resources
............................... 8
Site 9-13
Siting and Orientation ..........................9-10
Drainage
................................................. 11
Plantings
................................................. 12
Radon
..................................................... 13
Material Basics 15-51
Climate Zones ........................................ 15
Thermal Envelope
..............................16-19
Insulation
...........................................20-32
Barriers and Wraps
............................33-40
Sealants and Penetrations
................41-51
Below Grade Construction 53-69
Foundations .......................................53-55
Basements
........................................56-63
Crawl Spaces
....................................64-66
Slab-on-Grade
...................................67-69
Above Grade Construction 71-98
Exterior Walls .....................................71-82
Windows, Doors, and Skylights
........83-88
Floors
.................................................89-91
Attics and Roofs
................................ 92-97
Sunrooms
............................................... 98
Building Systems 99-125
Heating and Cooling ........................99-106
Ventilation
......................................107-112
Domestic Hot Water
......................113-116
Plumbing Fixtures
and Appliances
..............................117-118
Lighting / Electrical
........................ 119-125
Glossary and Index 127-146
Contents
How to Use This Guide .......................... 1
Energy Conservation:
A Whole Building Approach
................... 1
Building Quality and Durability
.............. 2
New York State
Code Requirements
............................... 2
NYSERDA Support ... .............................. 3
ENERGY STAR
®
and More
Restrictive Local Standards
.................. 3
High Performance Buildings
and Renewable Energy
.......................... 4
Working with Architects
and Engineers
......................................... 5
Inspections and
Performance Testing
.............................. 5
Building Commissioning
and Maintenance
.................................... 6
Owner’s Manual and
Homeowner Education
.......................... 6
Occupant Safety
..................................... 7
Further Reading and
Additional Resources
............................. 8
Background
BACKGROUND
BACKGROUND
1
This guide is, rst and foremost, meant
to assist New York State builders,
contractors, subcontractors and designers
improve the energy efciency of small-
scale residential construction. The guide
is also useful for existing and prospective
homeowners interested in developing
an understanding of the importance and
value of energy efcient construction
techniques. For both audiences, the
guide presents construction concepts for
buildings that promote energy efciency,
safety, durability, comfort and economy.
This guide is designed as an
easy-to-use reference that can be kept
in tool boxes used on the construction
site. While it incorporates information and
illustrations consistent with good building
science and construction practice,
it is not intended to be a complete
construction resource. Accordingly,
the guide addresses neither specic
code requirements, which are subject
to change, nor many other facets of
residential construction beyond those
associated with energy efciency.
Despite a wealth of building science
research over the past decade, there are
many concepts for which no denitive
recommendations are provided. This
reects the continuing evolution of energy
efcient construction techniques, the
advent of new materials and construction
methods and ongoing debate on topics
such as vented versus unvented attics
or the presence and location of a vapor
retarder. This guide leaves the nal
decision on such matters to the architect,
engineer and/or contractor, based on
the goals and construction approaches
selected for a specic building.
A whole building approach to building
design and construction is the starting
point of this guide. Every building is a
complex assemblage of thousands of
individual parts and systems that must
interact with each other, the site and
the environment. Building owners have
a major but largely unrecognized role in
how a building performs once occupied.
Owners establish the priority given to
energy efciency, determine the level of
acceptable comfort in a building,
and have the responsibility of operating
and maintaining the building once
construction is complete.
As buildings have grown in size and
complexity, and as owners’ expectations
for comfort have increased, the number of
design professionals and trades involved in
a single project has multiplied. Carpenters,
masons, roofers, plumbers, electricians,
sheet rockers, insulators and others
understand their work, but not necessarily
How to Use This Guide
Energy Conservation:
A Whole Building Approach
2
the work of others on the job site. For
example, the insulation installer unaware
of all piping or duct penetrations made
by the mechanical contractor and others,
or the sequence and method of installing
windows and doors, can leave signicant
gaps in the building envelope and paths
for air leakage and moisture damage.
For proper operation of today’s highly
insulated buildings, which often use
smaller, more efcient mechanical
systems, a coordinated effort that
treats the building as a whole and
not as a collection of isolated
components is essential.
Homes should withstand the test of
time. The use of quality materials and
workmanship following the energy
concepts suggested in this guide will
help ensure a durable and safe home in
which components and systems are built
to last. In addition to energy savings and
increased comfort, quality construction
achieved through the builder’s attention to
detail helps a home maintain its structural
integrity and maximize its resale value.
Codes set the legal minimum standard
to which a building must be constructed.
Construction requirements for detached
one- and two- family dwellings (and
townhouses not more than three stories
in height with separate entrances and
one-family dwellings converted
to bed and breakfast dwellings) are
found in the Residential Code of New York
State (RCNYS), with possible references
to the Plumbing, Fuel Gas, Mechanical
and Fire Codes of New York. The Building
Code of New York State (BCNYS) is
applicable to all other structures. For
energy conservation, all buildings must
also meet the requirements of the Energy
Conservation Construction Code of
New York State (ECCCNYS).
New York State codes are based on,
but not identical to, the family of model
codes published by the International
Code Council, Inc. (ICC). Preparation,
adoption and administrative oversight
of these codes are the responsibility of
the New York State Department of State.
Enforcement typically occurs at the
municipal level.
For the small-scale homes addressed
by this guide, general construction
requirements are primarily found in the
RCNYS. Energy requirements for efcient
energy use in these buildings are found
in either the RCNYS or the ECCCNYS.
Alternate code paths to document
compliance with the RCNYS or ECCCNYS
New York State Code Requirements
Building Quality and Durability
3
are provided in order to provide exibility
of construction, including the use of
innovative approaches and techniques.
In response to increasingly stringent
federal and State policies establishing
the minimum level of energy efciency
in buildings, builders and owners must
conrm that the most current codes
and standards are followed. (Codes are
typically updated on a three year cycle,
although interim revisions of specic
requirements are possible.)
Information on current and local
requirements, including submission
materials, inspections, testing, and any
alternate requirements for municipalities
that have adopted a More Restrictive
Local Standard, can be obtained from the
local code enforcement ofcial or the NYS
Department of State.
Program participation through
NYSERDA and other agencies or local
utility companies can make substantial
differences in a building’s energy
efficiency and energy costs.
Resources to determine available
programs and criteria include
nyserda.ny.gov and the Database of
State Incentives for Renewables and
Efficiency, www.dsireusa.org.
ENERGY STAR
®
is a reference to an
advanced building energy efciency
program developed by the U.S.
Environmental Protection Agency
for new construction and renovations.
The ENERGY STAR
®
label also
refers to energy efcient consumer
products and appliances that meet
or exceed federal energy efciency
and quality guidelines. ENERGY STAR
®
has long served as a building block
of NYSERDA’s residential program.
Although in most New York State
municipalities compliance with ENERGY
STAR
®
building standards is optional,
in recent years, select municipalities
have adopted ENERGY STAR
®
as
their More Restrictive Local Standard.
Alternate approaches to establishing
minimum requirements, such as the use
of above minimum HERS ratings for new
construction, are increasingly common.
For low-rise residential buildings,
New York State programs have
NYSERDA Support
ENERGY STAR
®
and
More Restrictive Local Standards
4
historically been based on the federal
ENERGY STAR
®
platform. Although
program offerings change, the following
are currently available:
New Construction: The New York
ENERGY STAR
®
Certied Homes program
requires new buildings to be constructed
to ENERGY STAR
®
standards, which
represents a signicant improvement
in energy efciency performance when
compared to code-compliant new homes.
All builders and owner-builders can
participate in the program, which requires
proposed plans to be reviewed by a
Home Energy Rater and the building to
be performance tested at the completion
of construction to ensure optimal
performance and quality construction.
Existing Buildings: NYSERDA’s Home
Performance with ENERGY STAR
®
program offers support to homeowners
for retrofitting existing homes. To
participate in the Home Performance
with ENERGY STAR
®
program,
contractors must be accredited by the
Building Performance Institute (BPI).
This guide applies to the typical new
home built to the State’s minimum
construction standards and incorporates
many principles associated with high
performance buildings designed to
perform signicantly above code. The
following ener
gy measures are not
addressed in this guide:
n
LEED certication
n
Super insulated structures
n
On-site energy (solar, wind,
geothermal, low-impact hydro,
biomass, biogas strategies)
n
Zero Energy Buildings
n
On-site water treatment
n
Green roofs
High Performance Buildings
and Renewable Energy
Courtesy of the Institute for Building Technology and Safety
5
Codes require specic inspections and
testing; additional visual inspections
should occur throughout construction to
ensure the quality of implemented work.
For energy efciency purposes, the most
common performance tests are associated
with building envelope tightness (blower
door test), and when mechanical system
ductwork resides outside the building
thermal envelope, duct tightness
(duct blaster test).
Although not mandated by code,
inspection using infrared imaging can also
be useful to detect missing insulation in
walls, roofs and ceilings; leaks at windows,
doors and penetrations; and other gaps in
the building thermal envelope. It is best to
undertake testing during the construction
process when corrections can be
accommodated most easily.
At construction completion and prior to
occupancy, all mechanical, plumbing
and electrical systems should be tested
Inspections and Performance Testing
Working with Architects
and Engineers
Drawings and specications for
new construction must demonstrate
compliance with applicable codes. These
must be signed and sealed by a New
York State licensed and registered design
professional (architect or engineer) and
submitted to the local code enforcement
ofce for approval before construction can
begin. For energy conservation purposes,
the ECCCNYS identies specic
information that must be included in the
submission package. Interim and nal eld
inspections are also required before a nal
certicate of occupancy is issued.
The architect and engineer can provide
recommendations on design issues,
material selection and construction details
to improve the building’s aesthetics,
functionality, energy use and occupant
health and safety. As the intermediary
between the contractor and owner, design
professionals help owners make informed
decisions, provide on-site inspections to
ensure that work is performed as intended
and assist the owner with administrative
matters including payments to the
contractor. Finally, for projects where
competitive bids from potential contractors
are solicited, the detailed construction
documents prepared by the design
professional are the means to ensure that
bids received will be truly comparable.
Courtesy of the Department of Energy
6
Homeowners should receive from
the builder an Owner’s Manual that
includes manufacturers’ instructions
and specications and operating and
maintenance requirements for all
equipment. The builder should conduct
a complete walk-through of the building
with the homeowner to ensure a general
understanding of how all systems work.
Improper function of a single component
can signicantly impact the overall
integrity of the house as well as
occupant safety.
In addition to the certicates and postings
on equipment required by code, the
Owner’s Manual should include basic
information on R-values of insulation
installed in walls, roof, foundation, slab
and ducts; U-factors of fenestration;
the types and efciencies of mechanical
equipment; manufacturers’ technical
materials on installed equipment; and
contact information for all suppliers,
and/or subcontractors responsible for
installation.
For high performance buildings, building
commissioning is a formal process
that occurs at the close of construction
to verify proper and complete installation
of building systems.
At construction completion, builders
should provide guidance to owners on
the appropriate scope and cycle
of maintenance for various components
and features. Maintenance and regular
check-ups of energy efciency
measures is as essential for a building
as it is for an automobile.
Owner’s Manual and
Homeowner Education
Building Commissioning
and Maintenance
to verify proper installation, calibration
and operation. Test results should be
reviewed by the design professional
and maintained by the owner. Required
adjustments and corrections should occur
before project closeout when all trades
and subcontractors have been paid in full,
although the need for minor adjustments
immediately following occupancy and
during the established warranty period
should be anticipated.
7
Most indoor air quality problems in
homes are associated with pollution
produced from gases or particles emitted
from construction materials, paints and
other nishes, carpets and draperies,
mechanical equipment, and cooking
and other natural occupant functions.
High temperature and humidity levels,
improper selection and installation of air
barriers or vapor retarders and unresolved
maintenance and moisture issues can
also increase the likelihood of pollutants
such as mold.
Radon is one of the most signicant
safety issues affecting occupant safety.
A naturally occurring, colorless and
odorless radioactive gas, radon comes
from the natural decay of uranium found
in nearly all soils. Radon typically moves
into homes through cracks and other
holes in the foundation. If trapped inside
and high levels of concentration are
reached, life-threatening health issues
can occur. Radon testing, and solutions
to incorporate into a home’s construction,
are readily available.
High efciency heating and cooling
equipment rely on a tight and well
insulated building envelope and
mechanical ventilation in order to
maintain a safe interior environment.
Properly designed, installed and
maintained ventilation equipment
delivers outdoor air into the house to
dilute emissions from indoor pollutants
and transports indoor pollutants out of
the home. Ventilation is a life safety feature
that affects the operation of equipment,
occupant comfort and the potential for
condensation and mold growth.
As codes continue to require tighter
buildings, provision of appropriate
and managed mechanical and natural
ventilation will become increasingly
critical. Whole house mechanical
ventilation is expected to be a
requirement of the next energy and
residential codes.
Occupant Safety
8
NYSERDA
nyserda.ny.gov
NYS Department of State
www.dos.ny.gov/DCEA/
energycode_code.html
Building America Solution Center
http://basc.pnnl.gov/
U.S. Environmental Protection Agency
www.epa.gov
U.S. Department of Energy
www.energy.gov
www.eere.energy.gov
Building Science Corporation
www.buildingscience.com
Green Building Advisor
www.greenbuildingadvisor.com
Journal of Light Construction,
The JLC Guide to Energy Efciency.
Hanley Wood (2011).
Krigger, J. and Dorsi, C.,
The Homeowner’s Handbook to
Energy Efciency. Saturn Resource
Management (2008).
Krigger, J. and Dorsi, C., Residential
Energy Cost Savings and Comfort for
Existing Buildings, 6th Edition.
Saturn Resource Management (2012).
Lstiburek, Joseph, Builder’s Guide
to Cold Climates. Building Science
Press (2006).
Further Reading and
Additional Resources
The following resources provide detailed information on energy efciency of buildings.
Among these, the Building America Solution Center (U.S. Department of Energy
Efciency & Renewable Energy) is a particularly valuable resource providing greater
information on the topics discussed in this guide.
Siting and Orientation .......................9-10
Site Selection
........................................... 9
Building Orientation
................................ 10
Drainage
................................................ 11
Plantings
................................................ 12
Radon
.................................................... 13
Site
SITE
SITE
9
Site Selection
Site selection should occur before nalizing building plans.
Sites should be chosen to best t the building and cause
the least environmental damage.
Incorporate proper site preparation techniques to lower environmental impact:
n
Conserve and protect existing natural areas.
n
Limit site disturbance, as feasible:
n
40’ from building perimeter.
n
25’ from built-up areas.
n
Distances that meet or exceed setbacks established
by applicable regulation or by utilities.
n
Minimize pollution during construction by controlling soil erosion,
airborne dust and water-way sedimentation.
n
Prepare an erosion and sedimentation plan prior to construction:
n
Plan for seeding and mulching.
n
Set up silt fences.
n
Provide earth dikes.
n
Create sedimentation traps.
n
Provide hay bales.
n
Use excavated material, such as backll to provide appropriate site drainage
away from the building.
n
Save valuable top soil for nal landscaping over backlled crushed stone.
SITING AND ORIENTATION
10
Building Orientation
Proper building placement and orientation are among
the most basic foundation blocks of the energy
efcient building.
n
To optimize daylighting and solar heat gain, buildings should be designed and
positioned so that south facing walls have the greatest window area with seasonal
shading provided by deciduous plantings and shading devices. North and west
facing windows, doors and skylights should be minimized.
n
Where possible, building placement should take advantage of natural, cross
ventilation provided by prevailing winds. In coastal areas, designing to capture
cooling sea breezes must be balanced by the need to minimize vulnerability to high
winds and ooding.
n
Even if solar technologies are not included in initial construction, site selection and
building orientation should anticipate addition of such technologies in the future.
SITING AND ORIENTATION
11
General
Functional above and below grade drainage is required
to create and maintain a dry and healthy building.
Proper drainage methods:
n
Conduct a percolation test prior to construction to determine permeability
of existing soil.
n
If required, divert surface drainage to a storm sewer or other approved point of
collection or disposal.
n
Grade site at least 6” per 10’ to drain away from foundation walls.
n
Install perforated pipe covered with silt cloth in gravel/crushed stone at
foundation footings.
n
Properly size and install gutters and downspouts to drain away from building to
daylight and/or a water retention area or rainwater collection system.
n
Create a rainwater collection system to reduce the amount of potable water
used for landscaping purposes.
DRAINAGE
12
PLANTINGS
General
Landscaping provides desirable shade for buildings and for
natural cooling of hardscape paved surfaces, which absorb
and retain heat.
n
Maximize landscaping with hearty plantings with minimal water needs.
n
Limit cultivated grass areas.
n
Plant deciduous trees around the building to provide shade in summer and allow
solar heat gain in winter.
n
Plant coniferous trees for year round shading and noise and wind control.
n
Plant trees with strong, deep roots appropriate to soil characteristics
to prevent land erosion and increase site stability.
n
Save existing trees on the site.
13
NOTES
• See NY Radon Map: www.epa.gov/radon/pdfs/statemaps/new_york.pdf
• See Joseph W. Lstiburek, Water Management Guide (Building Science Press, Inc., 2006).
General
Radon is an odorless, tasteless and invisible gas produced
by the decay of naturally occurring uranium in soil and
water. It is the second most common cause of lung cancer.
For most Americans, the greatest potential for exposure
to radon is in the home.
Radon exists at varying levels throughout the United States. Radon is emitted from the
ground to the outdoor air where it is diluted to an insignicant level by the atmosphere.
Because radon is a gas, it can travel through the soil and into a building through cracks,
joints and other openings in the foundation oor and wall.
Testing to determine the radon level at a specic site is relatively inexpensive and
essential. Radon resistant new construction typically costs between $250 and $750.
Some of these techniques are also benecial for moisture control.
A home with proper water management is likely a radon free home. Where high radon levels
exist, the following measures are typically part of a radon mitigation plan:
n
Gravel:
Use a 4” layer of clean, course gravel beneath the slab-on-grade.
n
Vapor retarder:
Place a vapor barrier (typically polyethylene sheet) atop the gravel to prevent
soil gases from entering the house.
n
Vent pipe:
Run a 4” solid PVC Schedule 40 pipe vertically from the gravel through the
roof to safely vent radon and other soil gases to the exterior of the house.
n
Sealing and caulking:
Seal all openings, cracks and crevices in the foundation slab (including at the
slab perimeter) and walls with appropriately selected caulk to prevent radon from
entering the house.
n
Junction box:
Install an electrical outlet in the attic if power venting is determined necessary after
testing (following construction completion).
RADON
MATERIAL BASICS
Climate Zones ....................................... 15
Thermal Envelope
............................16-19
General
................................................... 16
Thermal Bridging
.................................... 17
Envelope Testing
.................................... 18
Infrared Thermal Imaging
....................... 19
Insulation
.......................................... 20-32
General
................................................... 20
Materials
................................................. 21
Comparing R-Values
.............................. 22
Fiberglass Insulation;
General ............................................... 23
Batts (Blankets) ................................... 24
Flash and Batt Insulation
........................ 25
Cellulose Insulation;
General ............................................... 26
Dense Pack ......................................... 27
Blown (Dry) and Sprayed (Damp) ....... 28
Foam Insulation;
General ............................................... 29
Rigid Board ......................................... 30
Spray (Open or Closed Cell) ............... 31
Mineral (Rock or Slag) Wool
................... 32
Material Basics
Barriers and Wraps.......................... 33-40
General
................................................... 33
Air, Water, and Vapor Control;
General ............................................... 34
Barriers and Vapor Retarders ............. 35
Selection of Vapor
Retarders and Barriers ........................ 36
Weather-Resistive, Air,
and Radiant Barriers ........................... 37
Drainage Planes and Rainscreens ...... 38
Housewrap;
Installation ........................................... 39
Installation at Openings ...................... 40
Sealants and Penetrations..............41-51
General
................................................... 41
Sealant Chart
.......................................... 42
Sealants;
Caulk ................................................... 43
Spray Foam ........................................ 44
Exterior Wall Penetrations
...................... 45
Chimney Penetrations
............................ 46
Other Roof Penetrations
......................... 47
Flue Shaft Penetrations
.......................... 48
Exhaust Fan and Dryer Penetrations
...... 48
Plumbing Penetrations
........................... 49
Bathtub and Shower Penetrations
......... 49
Heating and Electrical Penetrations
....... 50
Recessed Lighting Penetrations............. 50
Interior Bypass Penetrations
.................. 51
MATERIAL BASICS
Illustration Key
Batt insulation
Foam insulation
Loose ll insulation
Rigid foam insulation
Sheathing (plywood, OSB)
Control layer (air, vapor, moisture)
Sealant (continuous)
Gypsum board
(wall or ceiling)
Wood blocking
Concrete
Gravel
Siding
15
Climate Zones
Climates zones, used to categorize climatic concerns of
temperature, moisture, wind and sun, including daily and
seasonal patterns, determine code requirements for
insulation and other building-related details. Climate zone
maps are included in all building and energy codes.
n
All New York State counties are Category A (moist) and are classied as one of
three climate zones.
CLIMATE ZONES
Climate Zone 4
Bronx Nassau
Queens Suffolk
Kings New York Richmond Westchester
Climate Zone 5
Albany Erie Ontario Saratoga
Cayuga Genessee Orange Schenectady
Chautauqua Greene Orleans Seneca
Chemung Livingston Oswego Tioga
Columbia Monroe Putnam Washington
Cortland Niagara Rensselaer Wayne
Dutchess Onondaga Rockland Yates
Climate Zone 6
Allegany Franklin Montgomery Sullivan
Broome Fulton Oneida Tompkins
Cattaraugus Hamilton Otsego Ulster
Chenango Herkimer Schoharie Warren
Clinton Jefferson Schuyler Wyoming
Delaware Lewis St. Lawrence
Essex Madison Steuben
16
THERMAL ENVELOPE
General
The building envelope is the boundary between the
building and the external environment that separates
the conditioned (heated/cooled) building interior from
unconditioned areas and/or the outdoor environment.
The building thermal envelope must form a continuous,
insulated enclosure around the conditioned space.
n
All spaces that are heated or cooled are contained within the building
thermal envelope.
n
All above and below grade walls (including windows and doors), oors and ceilings
that separate conditioned from unconditioned space are part of the building thermal
envelope. These assemblies must be insulated depending on how the house is
designed for use.
n
The gures below illustrate how the building thermal envelope changes based
on how the house is conditioned.
Unconditioned attic
Unconditioned basement
Unconditioned attic
Conditioned basement
Unconditioned attic
Unconditioned basement
Conditioned crawl space
Conditioned attic
Unconditioned basement
Conditioned attic
Conditioned basement
Unconditioned attic
Unconditioned basement
Unconditioned garage
17
THERMAL ENVELOPE
Thermal Bridging
Unwanted heat ow occurs through areas of minimum
thermal resistance or high conductivity, causing heat loss,
and/or moisture condensation.
n
Thermal bridging occurs through gaps in insulation or when high thermally
conductive materials (e.g. steel, wood, concrete) create pathways for heat loss
that bypass insulation (see photo).
n
Thermal bridging creates an uninterrupted “short circuit” between the interior and
exterior of a building, signicantly lowering the effective R-value.
n
This effect is most signicant in cold climates during winter when the indoor-outdoor
temperature difference is greatest.
n
Thermal bridging is eliminated when continuous exterior foam insulation, coupled
with full exterior or interior air sealing, is used. The exterior insulation keeps all
materials, including piping and electrical boxes, on the warm side of the wall,
reducing the likelihood of condensation within the foam and subsequent damage
caused by deterioration or mold.
Courtesy of Newport Ventures
18
THERMAL ENVELOPE
Envelope Testing
Buildings must be inspected and tested for air tightness
and insulation installation. Beginning in 2014, an Envelope
Air Leakage (blower door) test is likely to be required for
residential construction in New York State.
n
The air tightness of a building can be evaluated through visual inspection and by a
blower door test. Visual inspection throughout construction of all gaps, voids and
intersections is the most effective means to ensure that code-required tightness will
be achieved at construction completion without expensive removals to remediate
concealed conditions. Envelope air leakage tests can occur on buildings with an
exterior air barrier anytime after the barrier is installed and all penetrations of the
building thermal envelope have been sealed, and at nal inspection just before
occupancy. An envelope air leakage test prior to nal inspection is not useful if the
interior surface is intended to function as the air barrier.
n
Envelope air leakage door tests are typically conducted by installers and by
energy efciency experts such as HERS raters or certied through the Building
Performance Institute.
n
New York State requirements for building tightness are likely to be upgraded to
approach the requirements of the model codes, currently 3 air changes per hour
when conducted with a blower door at a pressure of 0.2 inches w.g. (50 Pascals).
NOTE
• Conrm current code requirements given ongoing efforts to increase air tightness of buildings.
19
THERMAL ENVELOPE
Infrared Thermal Imaging
Thermal imaging provides the visual means to evaluate the
quality and completeness of an insulation installation by
graphically depicting differences in surface temperatures at
the building exterior.
n
Thermal imaging (also referred to as Infrared or IR) is most valuable on new
construction projects to verify the completeness of installations in enclosed cavities
(dense pack or sprayed foam). In such instances, the image is most readable when
conducted from the interior.
n
Thermal imaging is not required for new construction since the quality of the
insulation installation must be visually inspected (a more effective quality control
process) before interior nishes are installed.
20
General
Insulation materials are used to minimize heat transfer
due to conduction (rate of heat ow) through the thermal
envelope. In New York’s climate, the goal is to retain heat
in winter and to minimize heat entry or retain cooled air
in summer.
n
Insulation typically comes in the following forms: batts and rolls, foam board (rigid
foam), loose-ll or blown-in (bers or pellets), and sprayed foam and foamed-in-place
(used at small areas to control air leakage or to insulate an entire building).
n
Insulation materials vary by thermal effectiveness, environmental impact, cost,
complexity of installation, density, drying capacity, resistance to air leakage, and
ability to provide other performance attributes such as re resistance or minimize
sound transmission (a function of material density).
n
Insulation is most commonly described by its R-value (rate at which heat is lost
through walls, roofs, and foundation); the higher the R-value, the better. In contrast,
the U-factor, essentially the inverse of the R-value), is used to describe individual
elements such as window or skylights, or to rate the overall wall or ceiling assemblies.
n
R-values, expressed per inch, vary by material: overall R-value is a function of
R-value/inch x thickness of insulation installation at wall, ceiling or roof assembly.
Minimum R-values are established by code, and vary across the 3 distinct climate
zones in New York State.
n
Insulation materials can have environmental effects in manufacturing or installation,
and can settle or deteriorate over time. For example, some types of foam
(polyurethane and polyisocyanurate) are blown with heavy gases (CFCs or HFCs) that
can, as they off gas over time, lose some of their effective R-value. Formaldehyde
has lost favor as an insulating material due to health concerns.
n
Because air leakage is another primary source of energy inefciency, insulation must
be either an air barrier itself or be in contact with a separate air barrier. Materials such
as dense pack, blown in cellulose or sprayed foam have the inherent advantage of
lling all holes when properly installed. Other materials, and specic locations (e.g.,
windows and doors) regardless of material selection, require a second step in sealing
all intersections, gaps and voids. The most common material for voids is sprayed foam.
n
Insulation efciency and durability is also impacted by the need to protect against
the movement of air and water (bulk or vapor) into the wall or roof assembly. This is
achieved by addressing air leakage using a continuous air barrier system and proper
selection and complete installation of vapor retarders, as determined necessary.
INSULATION
21
Materials
TYPE MATERIALS WHERE
APPLICABLE
INSTALLATION
METHODS
ADVANTAGES
Blanket: batts
and rolls
•Fiberglass
• Mineral (rock or slag)
wool
• Plastic bers
• Natural ber
• Unnished walls,
including foundation
walls
• Floors and ceilings
• Fitted between studs,
joists, and beams
•Do-it-yourself
• Suited for standard stud
and joist spacing that is
relatively free from
obstructions
•Relatively inexpensive
Foam
board or rigid
foam
•Polystyrene
•Polyisocyanurate
•Polyurethane
• Unnished walls,
including foundation
walls
• Floors and ceilings
• Unvented low-slope
roofs
• Interior applications:
must be covered with
1/2-inch gypsum
board or other
building-code
approved material for
re safety
• Exterior applications:
must be covered with
weatherproof facing
• High insulating value for
relatively little thickness
• Can block thermal short
circuits when installed
continuously over frames
or joists
Loose-ll and
blown-in
•Cellulose
•Fiberglass
• Mineral (rock or slag)
wool
• Enclosed existing
wall or open new wall
cavities
• Unnished attic
oors
• Other hard-to-reach
places
• Blown into place
using special
equipment,
sometimes poured in
• Good for adding insulation
to existing nished areas,
irregularly shaped areas,
and around obstructions
Rigid
brous
or ber
insulation
•Fiberglass
• Mineral (rock or slag)
wool
• Ducts in
unconditioned
spaces
• Other places
requiring insulation
that can withstand
high temperatures
• HVAC contractors
fabricate the
insulation into ducts
either at their shops
or at the job sites
• Can withstand high
temperatures
Sprayed foam
and foamed-
in-place
•Cementitious
•Phenolic
•Polyisocyanurate
•Polyurethane
• Open new wall
cavities
• Unnished attic
oors
• Applied using small
spray containers or
in larger quantities as
a pressure sprayed
(foamed-in-place)
product
• Good for adding insulation
to existing nished areas,
irregularly shaped areas,
and around obstructions
INSULATION
NOTE
• Manufacturers offer numerous products with varying environmental impacts. Whenever possible,
selections should be environmentally-friendly with respect to products used in the manufacturing
process or as blowing agents.
Extracted from DOE: http://energy.gov/energysaver/articles/types-insulation
22
Comparing R-Values
Relative R-Values
Fiberglass Batt Insulation: Total R-value by Cavity Depth
INSULATION
Material R-value/inch (ave.)
Cellulose (dense pack) 3.2
Cellulose (loose blown) 3.7
Fiberglass (loose) 2.2 - 2.7
Fiberglass (batt) 3.1 – 4.3
Rock Wool 3.0 - 3.3
Expanded polystyrene board (bead board) 4.00
Extruded polystyrene board 5.00
Polyurethane board 5.00
Polyisocyanurate board
(foil faced)
7.20
Open Cell Spray Foam 3.60
Closed Cell Spray Foam 6.50
Fiberglass Batt
Insulation
Framing Unit
R-13 2X4
R-15* 2X4
R-19 2X6
R-21* 2X6
R-24 2X8
R-30 2X10
R-38 2X12
* High density
NOTE
• Insulation values vary by location (e.g., wall vs. roof or ceiling) and effectiveness can diminish over
time. For example, once out gassing has occurred the effective R-value of polyisocyanurate may
decline to 6.0 – 6.5.
23
INSULATION
Fiberglass Insulation
General
Fiberglass insulation consists of extremely ne glass bers
most commonly manufactured into batts (blankets) or used
as loose ll. The insulating properties of berglass come
from the tiny air spaces between its glass bers, which
slow conductive heat ow.
n
Most common and least expensive type
of insulation.
n
Does not act as an air barrier.
n
Available with or without vapor retarder
facings, such as foil or Kraft paper.
n
Flame resistant facings available for areas
where insulation will remain exposed.
n
R-value of roughly R-3 per inch;
manufactured in various depths and
widths to t typical framing cavities.
n
Not recommended for gaps or in voids
around windows and doors, except as a
backer for foam or caulk air sealant.
n
Loose ll and blown in
insulation also
available with growing acceptance.
24
INSULATION
Fiberglass Insulation
Batts (Blankets)
To function as intended and retain its rated R-value,
berglass insulation must not be compressed
during installation.
n
Batts must be installed to fully ll the framing cavity without gaps and air spaces,
making complete contact with all six sides including sheathing and nished
wall surface.
n
Must be hand cut and trimmed to t snuggly around obstructions, such as plumbing
and electrical features, to maintain full thickness.
Incorrect
installation
Correct
installation
Compressed
batts
Batt sliced to
permit laying
in of pipe
Side stapled
(reduced
thickness)
Front stapled
NOTE
• Mineral wool, plastic bers and natural bers can also be used as batts.
25
Flash and Batt Insulation
Flash and batt insulation is a hybrid insulation method for
framed walls that combines some of the benets of
berglass with those of spray foam. It can easily be
incorporated into standard construction practice.
n
Fiberglass, which is not an air or vapor barrier, is used with spray foam, which
contributes additional thermal performance and air tightness.
n
The interior face of sheathing of 2x6 walls receives closed cell spray foam and
typically 6” of berglass batt insulation. The depth of the spray foam (often 2” – 3”)
depends on the foam, climate zone, and code requirements.
n
Because more labor is required, cost is greater than berglass batt insulation but less
than a full foam installation. Additional time for curing of foam must be anticipated.
n
Precautions followed for all foam and berglass insulation, including vapor retarders
and other details, must be adhered to.
INSULATION
Courtesy of IBTS
26
INSULATION
Cellulose Insulation
General
Cellulose insulation is primarily (80%) made from recycled
newsprint and other paper sources. As compared with
berglass and foams, it requires less energy to manufacture.
n
Cellulose insulation, used widely since the 1970s, is a low-cost insulation material,
generally comparable in R-value to berglass or rock wool. Compared to closed cell
and polyurethane foam insulation, cellulose has a lower R-value per inch but is much
less expensive.
n
The addition of up to 20% by weight of non-toxic borate compounds (may include
ammonium sulfate) provides resistance to re, insects and mold.
n
While cellulose is a hygroscopic material able to soak up and hold liquid water, its
vapor permeability supports drying of any moisture buildup. Use of a vapor retarder
is often not recommended, and consideration should be given to the specics of the
proposed installation.
n
Like other insulation materials,
long term exposure to water is
problematic. In cellulose, this can
cause sagging or corrosion of
metal fasteners, plumbing pipes or
electrical wiring.
n
Installation is typically dry spray,
damp-spray, or dense pack (dry
material under pressure installed
with a ll tube).
NOTES
• Manufacturers are required by law to provide the “settled thickness” on their bags.
• Blown in insulation should completely ll cavities and be at an even thickness throughout the attic.
• Attic rulers appropriate to cellulose should be placed around the attic to verify depth: typically
1 ruler for every 300 sq.ft., evenly distributed around the attic and clearly readable from the
attic access.
27
INSULATION
NOTE
• Fiberglass insulation can also be installed to comparable densities, although is typically subject to
the same vulnerabilities as noted above. Spray berglass is becoming increasingly available, with
bers typically mixed with acrylic bonding agent.
Cellulose Insulation
Dense Pack
Dense pack cellulose is installed in a similar manner as
other cellulose spray insulations although at a greater
density (approximately 3.5 lb/cu.ft.).
n
Properly installed, dense pack cellulose has good resistance to settling.
n
Dense pack cellulose in walls provides good thermal performance and, although not
an air barrier, signicant resistance to air leakage.
n
Dense pack cellulose is not recommended for unvented cathedral ceilings or
unvented at roofs where the potential for desirable drying of the cavity to the
exterior is less than at exterior walls.
28
INSULATION
Cellulose Insulation
Blown (Dry) and Sprayed (Damp)
Qualied contractors should be used for both blown and
sprayed installations. Precautions should be taken to
protect against blowing bers, including taping plastic
sheets at windows, doors, electrical boxes, etc.
n
Blown cellulose is a good solution for attics where dry ber is supported by the attic
oor or in an enclosed wall cavity. Because of material settling, where possible (in
oors), overspray should occur to provide desired thickness once settling occurs.
n
Sprayed cellulose is typically used for open wall and oor cavities in new
construction. The addition of water and/or adhesive during the installation process
creates a sticky material that adheres to sheathing and lls the cavity, signicantly
reducing airow.
n
Sprayed cellulose is installed to ll wall or oor cavities, with any excess material
scraped away. To conrm the correct amount of material has been installed, bag
count required for the R-value for the installed area must be veried.
Following manufacturer instructions, including moisture content for spraying and
temperature restrictions, is critical. Newly placed material is damp and must be
permitted to dry or be dehumidied until the moisture content reaches 25% or as
required by manufacturer. Moisture content should be checked prior to enclosure
of cavity.
29
INSULATION
NOTE
• Numerous resources are available to address potential health issues associated with foam. These
include the National Institute of Occupational Safety and Health, the Environmental Protection
Agency (EPA), and various industry sources such as www.spraypolyurethane.org.
Foam Insulation
General
Foam insulation provides a high R-value per inch
of thickness and, when properly installed, reduces
air inltration.
n
Made from polystyrene (expanded or extruded), polyurethane,
polyisocyanurate or phenol.
n
Uniformly solid.
n
Open cell foam allows water vapor to move through material more easily,
but has lower R-value for a given thickness.
n
Closed cell foam resists passage of vapor in both directions.
n
Must follow manufacturer installation specications and code requirements
with respect to required re protection coatings in certain applications.
n
Following application, ventilation of house is recommended in order to minimize
potential ill effects of out gassing.
Courtesy of DOE
30
INSULATION
Foam Insulation
Rigid Board
Insulation board is increasingly common for exterior
applications to provide a continuous surface with thermal
and vapor resistance and eliminate thermal bridging.
To meet code, additional interior insulation (berglass,
cellulose, or mineral wool) may be required between wall
studs or roof rafters/attic joists.
n
Rigid board foam insulation is used at roofs, walls, foundation walls, and slabs, as
well as at interior rim joists. Different foams are appropriate for each application, as
recommended by manufacturer.
n
Interior and exterior installations require precise tting and/or sealing of all
gaps and joints between rigid boards using compatible materials identied by
the manufacturer.
n
Installation requires supplementary use of small canisters of spray foam to seal larger
or concealed voids.
n
Rigid board insulation can improve overall thermal performance by eliminating
thermal bridging through framing, and can be detailed and installed to act as an air,
thermal and weather barrier (drainage plane).
31
INSULATION
Foam Insulation
Spray (Open or Closed Cell)
n
Material can be polyisocyanurate or polyurethane.
n
High R-value and effective air barrier can be achieved in a single application.
n
Can be sprayed, poured or injected into almost any space. Once in place, material
expands to completely ll the area. Because of the difculty of ensuring a uniformly
insulated surface within a concealed cavity, and the building damage possible
from incomplete coverage, completed installations should be veried with
thermal imaging.
n
Open cell foam allows water vapor to pass through and has a lower R-value for a
given thickness; depending on thickness, closed cell foam, with a higher R-value for
a given thickness, can act as a vapor retarder.
n
More expensive than other insulations.
n
Installation by experienced crews is critical. Precise following of manufacturer
recommendations will minimize the likelihood of shrinkage of materials, non-
adherence to adjacent framing members, or other problems when the depth of a
single lift exceeds manufacturer recommendation.
n
To minimize potential ill effects following application, ventilation following application
is recommended.
NOTES
• May require an approved thermal barrier, such as drywall or re rated coating.
• Urea formaldehyde (UF) foam, used in the 1970s, is no longer available for health reasons.
32
INSULATION
Mineral (Rock or Slag) Wool
Mineral wool insulation is a product made from molten
rock that is manufactured (using blown air or steam,
or spinning) to create mineral bers which are used in
building insulation.
n
Mineral wool is a durable insulation material that retains its insulation properties
in very low and very high temperatures. Insulation is comprised of +/- 97% mineral
materials: the remaining materials are binders (phenolic-formaldehyde resin) and/or
impregnating oil.
n
Because mineral bers do not absorb water or moisture, under proper conditions,
material that has been wetted will dry readily.
n
Has good sound proong characteristics resulting from the material’s capacity to
absorb sound.
n
Naturally non-combustible, offering good re resistance: the slow rate of heat
transfer helps resist re spread and does not contribute re spread through the
release of heat, smoke, or burning droplets.
n
Can be installed loose-ll or as a batt product.
33
General
n
Any airtight interior or exterior surface is considered an air barrier. In addition to the
variety of housewraps available, stucco, plaster, specic coatings, and properly
installed and sealed exterior plywood, OSB, exterior closed cell foam board, and
other sheathing materials, also provide protection from wind and material exposure
during construction. Properly installed interior gypsum board (with full air sealing at
windows, doors, oor/wall/ceiling junctions, electrical outlets and other penetrations)
is also an effective air barrier.
n
“Housewrap” is generically used to refer to synthetic materials (woven polyethylene-
ber paper and others) used as air barriers. These have generally replaced rosin-
impregnated paper and asphalt saturated felt, which were traditionally placed over
framing before installing siding. The primary function of this control barrier is to resist
air inltration and bulk water entry from the exterior.
n
Housewrap products are relatively light weight and produced in wide rolls to allow
for fast and continuous installation. Depending on application and material,
housewraps can serve as the weather resistive drainage plane that protects
inboard surfaces from water inltration. Because these materials are permeable
to water vapor, they permit drying of wall systems, helping to prevent mold growth
within the wall assembly and to protect insulation materials.
BARRIERS AND WRAPS
34
Air, Water, and Vapor Control
General
Air, bulk water, and vapor control are essential to protect a
building’s structure. Depending on material and application,
membranes, facings, coatings and foam insulation can
protect against the inltration of air, bulk water and vapor.
Manufacturer recommendations must be followed for all
installations.
BARRIERS AND WRAPS
Courtesy of DOE
35
Air, Water, and Vapor Control
Barriers and Vapor Retarders
Vapor retarders and barriers, rated by their permeability,
slow vapor transmission through the building envelope. In
New York State, before central air conditioning was
common, vapor barriers were placed on the interior side of
the building thermal envelope. As buildings have become
tighter for energy efciency and more commonly air
conditioned, best practice on the use, position, and choice
of vapor retarders (versus barriers) has evolved.
n
Moisture enters a building assembly as bulk moisture (e.g., leaks), or in moisture-
laden air, if an inadequate air barrier exists. Depending on climate and season,
moisture enters from the exterior (hot humid summer conditions) or from the interior
(generated from kitchens and baths).
n
As a function of the interaction of humidity and temperature (both ambient and
within the building assembly), moisture within the assembly can condense on colder
surfaces. If this condensation cannot dry (in at least one direction), the thermal and
structural integrity of building materials are compromised and can result in signicant
rot and mold damage.
n
To reduce the likelihood of moisture and mold damage in all buildings, all installations
require attention to detail to eliminate bulk moisture intrusion and moisture carried via
air leakage.
BARRIERS AND WRAPS
36
Air, Water and Vapor Control
Selection of Vapor Retarders
and Barriers
Examples of vapor retarders and barriers are as follows.
Higher perm ratings permit greater (and desirable) vapor
diffusion and drying of wall, ceiling, or oor assemblies.
n
Vapor retarders that resist vapor movement into framed building assemblies and
permit moisture penetrating the assembly to dissipate when conditions are cooler
and dryer are recommended for above grade use in New York State. Generally, Class
II and Class III retarders are recommended in New York State.
n
Class I Vapor barriers should only be considered for New York State’s coldest
climate, Climate Zone 6, where air conditioning is uncommon. Vapor barriers should
never be used on both sides of a wall or ceiling assembly, or on the interior side of
air-conditioned buildings. (The Climate Zone 6 home with central air conditioning can
successfully use a Class I interior vapor retarder as the vapor drive will be reversed
for only a short period of time.) When used, ventilation (mechanical or natural) should
be provided to control humidity.
BARRIERS AND WRAPS
Class Perm Rating Examples
Class I vapor retarder
(barrier)
<0.1
• On insulation facing: coated kraft paper,
aluminum foil, vinyl
• Polyethylene sheets
• Polyisocyanurate insulation boards
• Oil-base primers, vapor-barrier paints
• Vinyl wall covering
Class II vapor retarder 0.1 – 1.0 perms
• All materials resisting water
vapor diffusion
Class III vapor retarder 1.0 – 10 perms
37
Air, Water and Vapor Control
Weather-Resistive, Air, and
Radiant Barriers
Weather-Resistive Barriers that stop rain water from travelling through exterior cladding
provide a narrow space (drainage plane) that permits any rain water entering the cavity
to drain to the bottom of the wall and out. (A rain screen is a wider space between
the exterior cladding and weather-resistive barrier that is even more advantageous for
drying). Examples of weather-resistive barriers:
n
Kraft paper with asphalt.
n
Perforated asphalt felt.
n
Woven polyethylene-ber paper ‘housewrap.’
Air Barriers are materials that stop moisture-laden air from entering building assemblies,
reduce air leakage and, when placed at the exterior, wind-driven air from entering into
and through insulation. Air barriers can be separate from the vapor retarder/barrier,
and require caulking or sealants at joints between materials, exterior outlets and
switches, window and door frames, oor/wall/soft junctions, plumbing chases, chimney
enclosures, and all wire holes and other penetrations. Examples of air barriers:
n
Interior drywall, fully sealed for continuity and air tightness.
n
Exterior sheathing: plywood, OSB, fully sealed for continuity and air tightness.
n
All airtight interior or exterior surfaces if fully sealed for continuity and air tightness.
Radiant Barriers reect heat coming toward the barrier and retard heat ow. If used
alone (fastened to bottom of roof rafters or sheathing), the barrier’s shiny surface faces
the air space. When used in a fully insulated cavity without air movement (convection),
the R-value of the assembly can be substantially improved. Radiant barriers are less
common in new construction, instead providing the most benet when used in existing,
under-insulated buildings. Examples of radiant barriers:
n
Aluminum foil, typically bonded to kraft paper or roof sheathing.
BARRIERS AND WRAPS
38
Air, Water and Vapor Control
Drainage Planes and Rainscreens
Drainage planes and rainscreens at exterior walls, located
between the back of cladding and the face of weather
resistive barrier, help to reduce the forces that draw water
into the wall assembly. They provide great benet in
encouraging drainage of accumulated moisture and drying
to the exterior.
Can be created using vertical wood or metal strapping attached to wall structure, or with
manufactured materials such as the following to serve as a weather-resistive barrier and/or
create a benecial thermal break:
n
Three dimensional, webbed matrix (approximately ¼” – ½” thick).
n
Three dimensional matrix bonded to housewrap.
n
Drainable housewrap with 3-dimensional coating (approximately 1 mm. thick).
BARRIERS AND WRAPS
39
BARRIERS AND WRAPS
Housewrap
Installation
Housewrap must be installed in shingle-lapped fashion,
free of gaps or breaks, to provide complete protection.
Always follow manufacturers specications.
n
Housewrap acts as a drainage plane or backup barrier to keep moisture from wind
driven rain or snow off the structural sheathing and framing.
n
Serves as an effective air barrier if all seals, joints and penetration points are
taped and sealed. Taping the seams also protects the building during construction
(greater resistance to wind and tear).
n
Housewrap must be secured to sheathing with ring-shank fasteners or
per manufacturer instructions.
Cover nails at sheathing and
staple wrap per manufacturer
Lapped joints
Tape per manufacturer
NOTE
• Consult manufacturer product specications for housewrap exposure limits
prior to siding installation.
40
BARRIERS AND WRAPS
Housewrap
Installation at Openings
To eliminate water entry into the building, fastidious design
detailing and installation technique at windows and doors is
required. These locations are arguably the most common
sources of failure in buildings.
n
Openings must be properly taped, sealed and ashed following manufacturer
instructions.
n
All water must be directed outward by proper lapping of materials: upper materials
slip over lower.
Step 1 Step 2
Fold housewrap along
dashed lines
Cut housewrap along
solid lines
Trim uppermost
cut piece. Tack up
until window and head
ashing are installed
Drop uppermost cut piece
into place
Tape or staple to
secure nal position
Sill ashing
details vary by
manufacturer
Install head ashing
over jamb ashing
Install window
Install jamb ashing
over sill ashing
Step 3 Step 4
NOTE
• Consult manufacturers’ instruction for installing housewrap around windows,
doors and other openings.
NOTE
• See www.e.org for information on sealants and related products.
41
SEALANTS AND PENETRATIONS
General
Sealing joints and penetrations in the thermal envelope
prevents air leaks and interior and exterior damage and
discomfort. Locations requiring sealant include plumbing
and electrical xtures, pipes and wiring, and other
penetrations and gaps at HVAC and ventilation equipment
and around doors and windows.
n
In a 100 sq. ft. wall, one cup of water can diffuse through drywall without
a vapor barrier in a year, but 50 cups can enter through a ½” round hole.
n
Air sealing and moisture control make insulation more effective and protect
the building assembly from condensation and mold.
Common envelope air leakage points
Courtesy of EPA
42
SEALANTS AND PENETRATIONS
Sealant Chart
Given the importance of sealants in long term energy
performance, always select the best sealant for for a
given material and follow manufacturer recommendations.
New materials such as tapes are continually being
improved for longevity and performance.
Material
and Relative
Cost Factor
Exterior
Interior
Typical Use Benets Drawbacks Estimated
Lifetime
(Years)
Acrylic Latex
Silicone Caulk
$ $
n n
Use where slight
movement is
expected
Flexible and durable Difcult to paint
10 – 25
Fire Rated
Acrylic
Intumescent
Caulk
$ $ $
n n
Sealing penetrations
through re rated
assemblies or
penetrations through
oors. Use at high
temperature areas
such as around
chimneys
Fire rated (must
meet UL 1479
and ASTM E814),
exible, easy to
install and nish.
Good adhesion
to most building
materials.
10 – 15
Urethane
Foam Sealant:
One Part
$ $
n n
Around window and
door openings. Must
use re rated version
in required areas
Provides tight air
seal and conforms
to opening
Must be careful
not to overll the
opening
10 – 20
Urethane
Foam Sealant:
Two Part
$ $ $
n n
Rim Joists, tops of
plates in attic at,
at soft/eaves to
provide wind dam
Provides a tight air
seal, high expanding,
covers larger areas
Will outgas initially,
can be messy
10 – 20
Silicone Caulk
$ $ $
n n
Gaps ¼" or less Flexible and durable Difcult to paint
10 – 35
Acrylic Latex
Caulk
$ $
n
Interior projects with
gaps ¼" or less
Flexible, fast drying
and paintable
Difcult to clean up
10 – 15
Acoustical
Sealant
$
n
Sealing polyethylene
air barriers
Best for providing
tight seal
Difcult to clean up,
can be messy
> 20
Latex Caulk
$
n
Gaps ¼" or less Easy to clean,
paintable,
inexpensive
alternative
Inexible and not
very durable
2 – 10
Acrylic Caulk
$ $
n
Exterior applications Very exible and
durable over extreme
temperature ranges
Messy, difcult to
clean up
10 +/-
Butyl Caulk
$ $
n
Masonry or
intersections of
masonry to other
materials
Flexible, can
span bigger gaps
(maximum gap
should be less
than ¾"), usually
is color matched
Difcult to work
with, messy, high
shrinkage factor
8 – 10
43
SEALANTS AND PENETRATIONS
Sealants
Caulk
Specic caulking compounds are made specically for
concrete, brick, wood, glass and metal and are intended to
form a exible seal for cracks, gaps and joints less than
¼” wide.
n
May be pure latex, siliconized latex, polyurethane and other modern materials.
n
When selecting caulk, consider life expectancy, shrinkage over time, paintability
and clean up (soap and water or solvent).
n
Prep surfaces to ensure they are clean and free of debris.
n
Apply in one straight, continuous bead and tool to nish if necessary.
n
Completely ll crack, gap or joint; reapply where shrinkage occurs.
n
Backer rod must be used for areas greater than ¼”.
NOTE
• The terms caulk and sealant are often used interchangeably. Caulks or caulking compounds are
non-elastomeric, do not return to their original sizes after being stretched or compressed, and are
used for lling small joints (¼” less) where little or no movement is expected. Sealants are
elastomeric materials used to seal joints where movement (typically 25% to 50%) is expected.
44
SEALANTS AND PENETRATIONS
Sealants
Spray Foam
Spray foam is a readily available, easy to use material to
effectively air seal gaps and openings greater than ¼” wide.
Both 1-part and 2-part foam materials are available.
n
Openings to be sprayed with foam must be clean for proper adhesion. 1-part foam is
more forgiving and can be used under dusty conditions in an attic and basement.
n
To obtain an effective seal, foam must be sprayed in a continuous motion with no
voids or breaks.
n
To ll openings around windows and doors, a non-expanding, 2-part foam is
recommended. If a 1-part foam is used, the gap should be lled no more than half
way in order to reduce waste and prevent bowing and warping of surrounding
materials as foam expands during the curing process.
n
At top plates and when sealing large by-passes (e.g., at drop softs) where a rigid
backing material such as insulation board, rolled berglass batt, drywall, or radiant
bubble wrap will be installed rst and later sealed, the natural tendency of 1-part
foam to expand to close large gaps is benecial.
n
Once cured, foam can be trimmed so that nish materials can be installed on top.
Generally, foam cannot be successfully sanded or smoothed to blend with nish
surfaces such as drywall or wood trim.
NOTE
• Choose appropriate foam for specic application; see sealant chart on page 42.
45
SEALANTS AND PENETRATIONS
Exterior Wall Penetrations
n
All penetrations through the building thermal envelope must be sealed.
NOTES
• Completely seal penetrations with gaskets, spray foam or tape. Use products appropriate to
materials, following manufacturer recommendations.
• Because of deterioration due to exposure to the elements, monitoring and maintenance
of sealed penetrations is essential.
Neoprene gasket or
sealant continuous
around vent opening
Neoprene gasket or
sealant continuous
around light xture
Neoprene gasket or
sealant continuous
around pipe penetrations
Insulated
exhaust duct
Exhaust fan
Exterior light xture
Exterior faucet
46
SEALANTS AND PENETRATIONS
High temperature
sealant
Sheet metal
Sealant applied to all joints
Chimney Penetrations
Chimneys run vertically through the entire building and
penetrate the building thermal envelope at the attic oor
or roof level (depending on whether or not the attic is
conditioned). Sealant is required where the chimney
penetrates the building thermal envelope.
47
SEALANTS AND PENETRATIONS
Other Roof Penetrations
All roof penetrations, including skylights, light tubes, vents,
and other holes created for plumbing, mechanical and
electrical equipment, must be made watertight.
n
Materials selected for ashing penetrations should follow manufacturer
requirements and be evaluated for compatibility with adjacent materials.
n
Given the vulnerability of roof penetrations and the potential damage if leakage
occurs, always select the best available material and ensure proper installation.
Monitoring and maintenance is essential.
Courtesy of the Department of Energy
48
SEALANTS AND PENETRATIONS
Flue Shaft
Penetrations
n Flue shafts vent combustion
air from appliances such as
furnaces and water heaters,
creating building thermal envelope
penetration points in most homes.
n
Seal ues with high-temperature,
exible sealant to allow for pipe
expansion.
n
Conrm code-required clearances
to combustible materials before
installing or completing air barriers
around heat sources.
Exhaust Fan and Dryer Penetration
n Exhaust fans and dryer vents must vent directly to the exterior and not into attics,
basements, or buffer spaces such as garage or between oors. Because these
carry warm moist air, these should be completely sealed and insulated to prevent
condensation, in particular when contained in unconditioned spaces.
n
Exhaust hood systems capable of exhausting more than 400 cfm require make up air
at approximately the same rate. Make up air system requires a means of closure and
an automatic start when the exhaust system is operated.
High temperature
sealant
Top of
ceiling
Wood
blocking
(behind)
Sealant
adhesive or
gasket at
all joints
Fire stopping
Flue
49
SEALANTS AND PENETRATIONS
Plumbing
Penetrations
n Seal all plumbing penetrations at building
thermal envelope and at interior locations
such as under cabinets and by water heaters.
Bathtub and Shower
Penetrations
n Tubs and showers at exterior walls are common areas of signicant air leakage.
Air barriers should be placed and sealed before installation of the tub or shower,
extended beyond the insert, and attached and sealed to the surrounding air barrier.
Provide air barrier sealed at oor
and wall
Caulk or sealant, typical
50
SEALANTS AND PENETRATIONS
Heating and Electrical Penetrations
n Seal all plumbing and electrical penetrations, including receptacles, switches
and junction boxes.
Recessed Lighting Penetrations
ICAT rated recessed
light xture
IC rated recessed
light xture
Air seal interior
faces of soft
Courtesy of the Environmental
Protection Agency
n Recessed lighting xtures are
sources of potential air leakage
through the thermal envelope.
Sealing of xtures can occur at
the xture or (if located within a
soft) above the xture.
n
IC (insulation contact) xtures
(typically up to 100 watts of light
output) can make direct contact
with ceiling insulation but may
not be air tight. ICAT (insulation
contact and air tight) xtures
(light output capacity posted on
housing) are also sealed, stopping
the passage of air through the
xture and into a ceiling or attic.
51
SEALANTS AND PENETRATIONS
Interior Bypass Penetrations
n Sealing penetration points (bypasses) in walls, oors and ceilings between adjacent
oors and rooms prevents unwanted heat loss and gain by minimizing stack effect.
Duct chase between oors. Plumbing, electrical and HVAC penetrations between
oors.
Plumbing penetrations between oors.
BELOW GRADE
CONSTRUCTION
Foundations .....................................53-55
General
................................................... 53
Foundation Types
................................... 54
Foundation Drainage
.............................. 55
Basements
.......................................56-63
General
................................................... 56
Dampproong Basements
..................... 57
Unconditioned Basements
..................... 58
Conditioned Basements;
General ............................................... 59
Exterior Insulation Details ................... 60
Interior Insulation ................................ 61
Interior Insulation Details .................... 62
Rim Joists
............................................... 63
Crawl Spaces
................................... 64-66
General
................................................... 64
Vented Crawl Spaces
............................. 65
Unvented Crawl Spaces
......................... 66
Slab-on-Grade
.................................67-69
General
................................................... 67
Exterior Insulation
................................... 68
Interior Insulation
.................................... 69
Below Grade
Construction
BELOW GRADE
CONSTRUCTION
Illustration Key
Batt insulation
Foam insulation
Loose ll insulation
Rigid foam insulation
Sheathing (plywood, OSB)
Control layer (air, vapor, moisture)
Sealant (continuous)
Gypsum board
(wall or ceiling)
Wood blocking
Concrete
Gravel
Siding
53
FOUNDATIONS
General
Effective foundation design can create more comfortable
above grade and below grade spaces, reduce utility bills,
prevent moisture and structural problems and control the
effects of radon.
Foundations are supported by footings that spread the weight of the building below grade
to minimize movement. The size, depth, reinforcement and design of foundations and
footings are determined by code. Three types of residential foundations are common
in New York State:
n
Slab-on-grade.
n
Crawl space.
n
Full basement.
NOTES
• Radon control should be considered when testing determines high levels of radon present.
• Other foundation types, such as pile, monolithic or thickened edge slab, are less common,
in part due to New York State’s cold weather conditions.
Courtesy of IBTS
54
FOUNDATIONS
Foundation Types
Different materials systems are available for residential
foundations. The choice of foundation is often regional or
based on contractor preference.
The most common foundations for homes include:
n Poured reinforced concrete:
Wall type, poured reinforced concrete foundations are among the most common.
These require formwork, steel reinforcement, and applied insulation but are the least
labor intensive. Poured reinforced concrete is typical for piers for porches, decks and
other small structures and additions.
n CMU (Concrete Masonry Unit):
Laid-up blockwork is more labor intensive than poured concrete. One advantage, in
particular for more complicated foundation designs, is its ability to be easily altered
during construction. Applied insulation is required.
n ICF (Insulated Concrete Forms):
A newer type of foundation consisting of stacked insulated forms. Reinforcement is
placed inside of hollow forms and concrete is poured inside to bond the structure.
ICFs have the benet of forming an integral and continuous insulated foundation,
although by isolating the thermal mass of the concrete from the inside of the building
envelope, some of the positive effect is negated.
n Pre-engineered concrete:
Panels are fabricated off-site and shipped to the job site for assembly per
manufacturer specications. Panels require absolute water-sealing, positive drainage
and bulk water control on the exterior and underneath.
NOTES
• At all locations, seal interface between the foundation and the exterior wall to reduce
inltration into the home.
• Insulate foundations per code and ensure insulation coverage is continuous and complete.
Use only insulation approved for below-grade use.
55
FOUNDATIONS
NOTES
• See damproong basement walls on page 57.
•
See Ltsiburek, Joseph. Water Management Guide. Somerville: Building Science Press, Inc., 2006.
Foundation Drainage
Managing water at the foundation is key to keeping
groundwater and roof water collected through ashing and
gutter systems out of the building.
Primary construction techniques to prevent the buildup of water at the foundation include:
n
Drain water at the foundation footing with a perforated drainage pipe embedded
in gravel, covered with lter fabric and located at the lower perimeter of the
foundation footing.
n
Sloped pipe around the building should direct water away from the building or
to a collection point of daylight. Design should include drainage at basement
window wells.
n
In areas or sites prone to water problems, include provisions for secondary
interior drains and/or a sump pump. Secondary interior drains should be enclosed,
where possible.
n
Slope grade away from building perimeter between 5% and 15%. Greater slopes
pose the risk of causing erosion to occur.
n
Ensure roof water is directed away from building perimeter a minimum of 2’. May
require downspouts (leaders) with extensions at grade or with subgrade connections
to below grade piping.
4” perforated drain pipe at footing.
Drain downhilll to daylight or sump
pit within basement.
Dampproong or cement-based
waterproong
Capillary break
(dampproong or membrane)
56
BASEMENTS
General
Basements are commonly used for living space, mechanical
equipment, laundry or storage. A basement may be
conditioned or unconditioned based on intended use.
Basements can be either conditioned (heated or cooled) or unconditioned:
n Conditioned basements:
n
Foundation walls part of the thermal envelope must be insulated on the exterior
or interior.
n
Mechanical ductwork and pipe insulation is not required although is
considered best practice.
n Unconditioned basements:
n
Not part of the thermal envelope.
n
Ceiling must be insulated.
n
Mechanical ductwork and piping must be insulated.
NOTE
• Many basements have both conditioned and unconditioned sections. Walls and doors separating
conditioned from unconditioned spaces must be insulated.
Courtesy of Conservation Services Group
57
BASEMENTS
Dampproong Basements
Damp basements are common. While it is difcult to
absolutely waterproof a basement, there are ways to
minimize dampness.
Masonry materials are inherently porous; moisture in the soil will penetrate masonry
walls or oors and make its way into the building. Any moisture absorbed by masonry
walls must be permitted to dry. Waterproof but non breathable coatings are likely to fail
in areas exposed to excessive moisture.
n
Dampproong:
n
A coating or membrane directly applied to below grade masonry foundations as a
capillary break to minimize absorption of moisture into the masonry.
n
Applied or installed to exterior walls and at the joint between the foundation
footing and perimeter foundation walls.
n
Historically, bituminous/tar coatings were used. Many choices are now available,
including cement-based materials, synthetic coatings and membranes.
n
Below Grade Slabs:
n
For normal installations, concrete slab should be placed over XPS (extruded
polystyrene) rigid board insulation over a 6 ml polyethylene vapor barrier over
coarse gravel. The rigid board insulation can act as the vapor barrier if joints
are well sealed, although many nd sealing of the polyethylene barrier easier
to accomplish.
NOTE
• Basements on soil with a high water content or at the foot of a hill may require sump pumps.
58
BASEMENTS
Unconditioned Basements
Unconditioned basements can increase moisture
challenges and limit the opportunity to use this space.
Disadvantages of unconditioned basements:
n
May be more expensive than conditioned basements since the basement
ceiling must be insulated, all penetrations sealed, and mechanical ductwork
and piping insulated.
n
May be more vulnerable to moisture issues and deterioration due to freeze-thaw
since the foundation wall is uninsulated.
n
Because the uninsulated foundation wall is vulnerable to moisture issues
and deterioration due to freeze-thaw, proper drainage at the foundation must
be provided.
NOTES
• Perimeter footing drain system is essential.
• If basement may be nished in the future, construction details should anticipate this
future conversion.
Flashing
Sill gasket
Ground slope
away from building
(minimum 5%)
Dampproong
Footing drain
Vapor retarder per
climate zone
Insulated mechanical
ducts and vents
Capillary break
(dampproong
or membrane)
59
BASEMENTS
Conditioned Basements
General
Conditioned basements require insulation that is installed
at the interior or exterior. Both approaches create habitable
space and do not require mechanical ductwork and pipes
to be insulated.
There are many advantages of exterior rigid board insulation:
n
Easy to achieve continuous thermal and air leakage boundary that minimizes thermal
bridging and reduces heat loss through the foundation.
n
Locating masonry mass inside of the building thermal envelope helps to regulate
heating/cooling and increase comfort.
n
Serves as a capillary break to moisture intrusion.
n
Protects exterior dampproong from damage during backlling.
n
Protects foundation from the effects of freeze-thaw cycle; reduces the potential for
condensation on surfaces when basement is properly drained.
n
Conserves room area relative to interior insulation.
Disadvantages of rigid insulation on basement wall exterior:
n
Some exterior insulation materials are particularly susceptible to insect infestation.
NOTES
•
Proper detailing to match manufacturer recommendations is critical.
•
If radon gas is present, a mitigation system beneath the basement oor is required.
60
BASEMENTS
NOTES
• Perimeter footing drain system is essential.
•
Proper details for insect control and/or termite-insect barrier required.
• On interior side of the basement wall, moisture resistant, breathable coating and/or air space
between foundation and new wall framing is recommended.
Conditioned Basements
Exterior Insulation Details
Exterior wall insulation protects dampproong applied to the exterior of foundation walls.
Flashing
Sill gasket
Ground slope
away from building
(minimum 5%)
Dampproong
Capillary break
(dampproong
or membrane)
+
/
-
3/8” cement board or
coating to 8” above grade
61
BASEMENTS
NOTES
• Only rigid insulation rated for exposed application can be used without drywall.
• Vapor barriers (vinyl wall coverings, ooring or vapor impermeable paints) are not recommended
at walls or oor.
Conditioned Basements
Interior Insulation
Advantages of interior basement wall insulation:
n
Mechanical ductwork and pipes do not require insulation.
n
Wider choice in insulation materials, since it will not be exposed to the elements.
n
Threat of damage from insect infestation is minimized.
Disadvantages of interior basement wall insulation:
n
Higher likelihood of moisture weeping through foundation walls.
n
Requires superior air sealing details and vapor retarder installation.
n
Room area diminished by thickness of insulation and wall framing.
62
BASEMENTS
Conditioned Basements
Interior Insulation Details
Options for interior basement wall insulation:
Sill gasket
Ground slope
away from building
(minimum 5%)
Dampproong
or cement-based
waterproong
Footing
drain
Capillary break
(dampproong
or membrane)
Wood furring
to create
air space
and serve
as nailing
surface
Vapor retarder per
climate zone
Gypsum wall
board with
vapor retardant
paint
Flashing
Sill gasket
Ground slope
away from building
(minimum 5%)
Dampproong
or cement based
waterproong
Footing
drain
Capillary break
(dampproong
or membrane)
Batt
insulation
in cavity
Vapor retarder per
climate zone
Gypsum wall
board with
latex vapor
retardant paint
Flashing
NOTE
• Due to the possibility of trapping moisture behind drywall and nish assembly, permitting mold
growth, details must be carefully resolved and accurately implemented. Means to allow drying to
the inside and dehumidication may be required.
Rigid board insulation Rigid board and batt insulation
63
BASEMENTS
NOTE
• Rim joists (or top plate) at attic are also part of the building thermal envelope and require
similar treatment.
Rim Joists
Rim joists (or rim/band joists), located at the perimeter of
oor framing, are often overlooked when insulating building
walls. When poorly insulated or sealed, these are signicant
points of heat loss/gain. Because rim joists are always part
of the building thermal envelope, they must be insulated
whether the basement is unconditioned or conditioned.
n
Spray foam is frequently used for rim joist insulation, especially at plumbing and
electrical penetrations.
n
Rim joist insulation must be continuous with wall insulation and have the same
R-value to maintain the building thermal envelope.
n
A coating for re protection (thermal barrier) may be required for foam applied to sill
plates, box headers, and rim joists unless the foam meets the thickness, density, and
ame spread rating required by code.
2” minimum spray foam
insulation to provide
continuous thermal barrier
Rim joist
(Basement)
Sill gasket/seal
64
CRAWL SPACES
NOTE
• Where required, radon mitigation systems require a passively or mechanically ventilated
crawl space.
General
Crawl spaces below buildings have insufcient height, as
determined by code, for most people to stand upright.
Crawl spaces often have dirt oors and can be vented or
unvented. Exposed materials, including framing members,
may be susceptible to deterioration through contact with
the earth or moisture moving upward from unprotected
ground or inward from the exterior.
For both vented and unvented crawl spaces:
n
Install a capillary break, such as an EPDM membrane, between masonry and
any wood framing to reduce water movement. A membrane can also serve
as a termite shield.
n
Dampproof the below grade portion of the foundation wall to prevent
absorption of ground moisture.
n
Install an exterior foundation drainage system at the footing (perforated drain pipe
sheathed in lter fabric and embedded in gravel).
n
Install a vapor barrier (EPDM or polyethylene sheet) across the crawl space oor
to prevent soil moisture from migrating into the crawl space. Overlap and tape all
seams, extend up the crawl space walls and seal completely to achieve air-tightness.
n
Recommended option: pour a thin concrete slab over the polyethylene vapor barrier.
65
CRAWL SPACES
Vented Crawl Spaces
Crawl spaces were traditionally vented to mitigate moisture,
requiring seasonal maintenance.
n
Vented crawl spaces are losing favor in New York State since, in summer conditions,
moist moisture-laden air moving into vented crawl spaces can condense on cold
concrete or other surfaces.
n
To minimize adverse effects where vented crawl spaces are used, vapor barrier
should be installed at grade and rmly secured to the wall, and vents sized to meet
code requirements. Blocking in or closing of vents is recommended in winter to
prevent freezing.
n
The oor above a vented crawl space is part of the building thermal envelope
and must be sealed and insulated.
n
Support insulation with mechanical fasteners to maintain
contact with the oor above.
n
Cover the insulation with housewrap or other material to protect insulation.
Flashing
Vapor retarder per climate zone
Wood strip
to secure
vapor barrier
Polyethylene
or alternate
membrane
vapor barrier
Sill gasket
Ground slope
away from building
(minimum 5%)
Dampproong
Footing
drain
66
CRAWL SPACES
NOTES
• An access hatch should be located through the oor above or through
an insulated access door in the perimeter wall.
• Vapor barrier should not extend up the full height of the crawl space wall.
Unvented Crawl Spaces
In buildings with proper exterior drainage and moisture
control and a relatively low water table, unvented insulated
crawl spaces are a good, energy efcient option.
n
Insulating crawl space walls with rigid insulation can be easier and less expensive
than insulating the oor of the conditioned space above.
n
Properly insulated and sealed crawl space walls can save energy costs
and increase comfort.
n
Heat transferred through the uninsulated oor above keeps the crawl space
from freezing, allowing placement of plumbing and ductwork within the crawl space.
Flashing
Vapor retarder per climate zone
Sill gasket
Ground slope
away from building
(minimum 5%)
Dampproong
Footing
drain
Wood strip
to secure
vapor barrier
Polyethylene
or alternate
membrane
vapor barrier
67
SLAB-ON-GRADE
General
A foundation with a slab-on-grade oor is often the least
expensive foundation system. Floors consist of a concrete
slab poured over rigid board insulation over vapor barrier
over gravel.
n
Slabs-on-grade lose energy primarily as a result of heat conducted outward and
through the slab perimeter.
n
Only the perimeter slab edge requires insulation; the thermal mass of the earth
serves as a natural insulator at the underside of the slab.
n
Slab edges must be insulated from the top of the slab (on the inside or outside of
the foundation wall) downward.
Keys to an effective slab foundation:
n Moisture control:
Use a site and building drainage system to direct rainwater and groundwater
away from the foundation.
n Airtight construction:
Seal interface between the slab, foundation and exterior wall to reduce air leakage.
n Complete insulation coverage:
Properly install the correct insulation levels and ensure the insulation
coverage is continuous and complete.
n
Use insulation products approved for below grade use.
NOTE
• When a building is designed to optimize solar or mass storage, insulation is
required under the slab.
Courtesy of DOE
68
SLAB-ON-GRADE
NOTE
• Protect diagonal or horizontal insulation with gravel or a minimum of 10” of soil.
Exterior Insulation
Rigid insulation is installed directly around the exterior
perimeter of the slab and footing to a depth required
by code.
n
Insulation can be installed either vertically, vertically then under the slab, or vertically
and diagonally outward from the foundation.
n
Extending the insulation outward beyond the foundation helps protect the
footing from freezing.
n
The above-grade portion of the insulation exposed to outside elements must be
covered with metal, masonry, cement parging, or another approved membrane or
material to protect it from damage.
n
Exposed edges of the insulation (above and below grade) should be covered with
a protective membrane to serve as a capillary break and to protect the insulation
from termites and physical impacts.
Vapor retarder
per climate zone
Insulation
extended
vertically then
turned 45°
to required
depth
Monolithic slab
Monolithic slab
Non-monolithic slab
Vapor retarder
per climate zone
Vapor retarder
per climate zone
Insulation
extended
below
grade to
top of
footing
Insulation
extended
below
grade to
top of
footing
69
SLAB-ON-GRADE
Interior Insulation
Rigid insulation is installed against the interior side of
the foundation wall or horizontally under the slab to
a depth required by code.
n
Insulation can be installed vertically from the top of the slab edge to the
foundation footing or vertically from the top of the slab edge then horizontally
underneath the slab.
n
Interior and exterior insulation have similar thermal performances.
n
Interior insulation is less expensive to install than exterior insulation, does not require
exterior protection for long term durability, and may offer better protection from
insect damage.
Vapor retarder
per climate zone
Wall Insulation
Slab Insulation
Insulation to
minimize thermal
bridging
Rigid insulation
at slab edge
Insulation
extended to
top of footing
Vapor retarder
per climate zone
Flashing
Sill gasket
Ground slope
away from building
(minimum 5%)
Dampproong
Footing
drain
Flashing
Sill gasket
Ground slope
away from building
(minimum 5%)
Dampproong
Footing
drain
Insulation to
minimize thermal
bridging
Rigid insulation
at slab edge
ABOVE GRADE
CONSTRUCTION
Exterior Walls ................................... 71-82
Sheathing
............................................... 71
Wood Framing
........................................ 72
Metal Framing
........................................ 72
Cladding;
Wood, Cement Board,
Aluminum, and Vinyl
........................... 73
Stucco and Masonry
........................... 74
Advanced Framing;
General ............................................... 75
Corner Connections ............................ 76
Junctions with Interior Partitions ........ 77
Headers .............................................. 78
Narrow Cavities
...................................... 79
Mass Walls
............................................. 80
Structural Insulated Panels (SIP)
............ 81
Insulated Concrete Forms (ICF).............. 82
Windows, Doors, and Skylights
.....83-88
General
................................................... 83
Window Frames
..................................... 84
Window Labels
....................................... 85
Window Installation
................................ 86
Door Installation
..................................... 87
Skylight Installation
................................ 88
Floors
................................................ 89-91
Separating Conditioned
and Unconditioned Spaces ................ 89
Cantilevered
........................................... 90
Level Changes
........................................ 91
Attics and Roofs
..............................92-97
Vented Attics;
General ............................................... 92
Loose Fill (or Batt) Insulation .............. 93
Access Hatch ...................................... 93
Pull-Down Ladder ............................... 94
Full-Height Door Access ..................... 94
Unvented Attics;
General ............................................... 95
Spray Foam Roof Insulation ............... 96
Fiberglass Batts and
Rigid Board Insulation......................... 96
Knee Walls .......................................... 97
Knee Wall Access Door ...................... 97
Sunrooms
.............................................. 98
Above Grade
Construction
ABOVE GRADE
CONSTRUCTION
Illustration Key
Batt insulation
Foam insulation
Loose ll insulation
Rigid foam insulation
Sheathing (plywood, OSB)
Control layer (air, vapor, moisture)
Sealant (continuous)
Gypsum board
(wall or ceiling)
Wood blocking
Concrete
Gravel
Siding
71
EXTERIOR WALLS
Sheathing
Sheathing provides a continuous surface at the exterior
face of the building envelope that contributes to building
stability and durability, resistance to air movement, and,
when insulated, thermal resistance.
n
Insulated sheathing (top photo), typically used in addition to insulation installed from
the interior within the wall cavities, provides an ideal continuous thermal barrier.
The most common types of insulated sheathing are Expanded Polystyrene (EPS),
Extruded Polystyrene (XPS), and Polyisocyanurate (Polyiso).
n
Taping of joints between panels (bottom photo) is required for air and water
tightness and proper performance. Careful attention to details and installation, as
recommended by manufacturer and appropriate for local conditions, is essential.
Courtesy of IBTS
72
EXTERIOR WALLS
Wood Framing
Wood is readily available and in New York State remains the
material of choice for most exterior walls, oors and roofs
in residential construction.
n
Material selection (including species and grade) and detailing are critical due to
wood’s vulnerability to rot and insect or termite attack.
n
Although wood is a fair insulator
at approximately R-1 per inch, it
is much less insulative than other
insulation materials.
n
Standard wall framing makes up
20 – 25% of the total wall area.
The reduction in overall R-value
resulting from wood framing can
be mitigated by exterior continuous
insulation and advanced framing
techniques.
Metal Framing
Metal is an alternative to wood for residential construction.
Although more expensive and conductive, metal has greater
spanning capacity and is not susceptible to insect attack.
n
Metal or steel framing is highly conductive. Although there is less mass than
wood, the conductivity of metal makes a building more prone to energy loss and
condensation issues.
n
High conductivity reduces the effective performance of insulation in metal
frame assemblies.
n
Cavity insulation alone is not adequate to insulate a metal framed house.
Continuous rigid insulation on the exterior wall is required.
Courtesy of IBTS
73
EXTERIOR WALLS
NOTES
• Some cladding types, such a vinyl and aluminum siding, do not require venting.
• Always provide air space if recommended by manufacturer.
Cladding
Wood, Cement Board, Aluminum, and Vinyl
Exterior cladding acts as the outward component in a
rainscreen assembly, helping to prevent water from
entering exterior wall assemblies.
n
Wall cladding may be wood, cement board, stucco, vinyl or aluminum.
n
With the exception of vinyl and metal, all cladding gets saturated. In all claddings,
open joints and gaps can develop over time, allowing wind driven rain to enter the
wall system.
n
Most cladding systems are installed with vent and weep holes, providing intentional
air movement that permits walls to dry properly.
n
Air spaces also contribute to thermal performance and wind pressure equalization,
as well as accommodate natural movement in buildings due to settlement and
seasonal changes.
Wood siding
(furring or rain
screen not
shown)
Cement board,
vinyl or aluminum
siding
(furring or rain
screen not shown)
Vapor retarder per
climate zone
Vapor retarder per
climate zone
Air space
Siding, with air space Siding, no air space
Housewrap Housewrap
74
EXTERIOR WALLS
Cladding
Stucco and Masonry
While ventilated rainscreens benet all cladding types, they
are essential for masonry and strongly recommended for
cement board. To permit full drying of the wall assembly,
follow manufacturer recommendations for position,
material and detailing.
Cement
board and
stucco
Vapor retarder per
climate zone
Air space
Brick veneer
Vapor retarder per
climate zone
Air space
Housewrap Housewrap
Cement board or stucco Brick masonry veneer
Rain screen Rain screen
75
EXTERIOR WALLS
Advanced Framing
General
Advanced framing, also known as Optimal Value
Engineering (OVE), is a technique that reduces the amount
of wood used to frame a building without compromising
structural integrity.
n
The goal of advanced framing is to reduce unnecessary wood around windows,
headers, corners, wall intersections, etc. Among other details, this typically includes
an increase in stud spacing (to 24” o.c.) and use of 2x6 wood framing.
n
Can reduce thermal bridging by up to 25% by allowing more room for cavity
insulation.
OVE: Insulated
header at load
bearing wall
OVE: Ladder
blocked for
intersection with
interior wall
OVE: Use 2-stud
corners (insulated)
OVE: Eliminate excessive
framing at openings
OVE: No header required
at non-bearing walls
Typical applications for
advanced (OVE) framing:
OVE: Eliminate
excessive framing
at openings
OVE: Use
single top
and
bottom
plates
76
EXTERIOR WALLS
Advanced Framing
Corner Connections
Traditional corner framing with 3 and 4 studs wastes wood
and reduces the total wall R-value. 2-stud corner framing is
preferable to minimize pockets of uninsulated voids after
exterior sheathing is installed.
n Use of 2-stud corners requires use of wood backup cleats, metal drywall clips or
other devices to serve as backing for nish material.
77
EXTERIOR WALLS
Advanced Framing
Junctions with Interior Partitions
Extra studs used in exterior walls at junctions with interior
partitions to provide solid nailing for drywall results in
locations that lack insulation.
Alternative techniques can reduce the number of studs while providing strength
and nailing surfaces:
n
Ladder blocking at wall junctions:
Install horizontal (ladder) blocking
where the partition will be secured to
add support for the interior wall.
n
Drywall clips at wall junctions:
Install clips before installing the next
sheet of drywall.
2x6 wall studs
Flat 2x3 (ladder)
blocking
2x4 framing at
interior partitions
2x6 bottom plate
2x6 top plate at
intersecting walls
2x6 top plate at
intersecting walls
2x6 bottom plate
Drywall clips
as required
2x6 wall studs
Drywall clip
78
EXTERIOR WALLS
Advanced Framing
Headers
A single header can be used in most locations instead of a
double header.
n
Advanced framing permits elimination of window jack studs, thus creating the
opportunity for additional wall insulation. Headers can be notched to connect to
the single stud or attached with a metal header hanger.
n
At non-bearing walls, insulation can be maximized since no (structural) headers
are required. Framing need only be sufcient to create appropriate window or
door openings.
Single 2x6 top plate
2x6 support
Structural header
Rigid board insulation
79
EXTERIOR WALLS
Narrow Cavities
Narrow cavities must be sealed and insulated to eliminate
air inltration into the building.
Where possible, without compromising structural concerns or placement of windows and
doors, framers should avoid narrow cavities.
n
To minimize the number of narrow cavities, careful attention to wall framing design
should be paid by the design professional and the builder.
n
Narrow cavities can best be avoided when placement of vertical framing members
is kept on a modular schedule (although modication for placement of windows and
doors may be necessary) and when advanced framing techniques are used.
n
Spray foam insulation with appropriate backers should be used to seal and insulate
where narrow cavities are unavoidable.
Narrow cavity at window and door openings
80
EXTERIOR WALLS
Mass Walls
Mass walls provide energy efciency through mass rather
than insulation. Exterior walls constructed of concrete
block, concrete, insulated concrete form, masonry cavity,
brick, earth, adobe and solid timber or logs, are heavier per
cubic foot than traditional frame walls and specically
designated as mass walls (by weight) by the code.
Mass walls can supplement both heating loads in the winter and cooling loads in the
summer if carefully designed.
n
In a heating climate, the sun’s energy is collected and stored during the day and
released at night. Because mass walls absorb heat from the sun and radiate it to the
interior, less insulation is required than for a frame wall. If the mass wall will receive
direct summer sun, shading should be provided.
Insulation requirements are dependent on how the insulation is distributed between the
interior and exterior walls.
n
If more than half of the insulation is on the exterior, mass walls are permitted to have
a lower R-value than permitted for other wall systems.
n
If at least half of the insulation is on the interior (limiting the ability of the building to
use stored heat) additional interior insulation, approaching that required for a frame
wall, is required.
Brick veneer
Stainless steel ties
(brick to concrete block)
Air space
Concrete block
Rigid board
insulation
Batt insulation
in cavity
Gypsum board
Vapor retarder per
climate zone
Mass wall with interior insulation
81
EXTERIOR WALLS
NOTE
• Can be manufactured with precut openings for windows and doors or with grooves and voids for
electrical wiring and heating/cooling ducts and pipes.
Structural Insulated Panels (SIP)
n
SIPs are factory-built, insulated wall assemblies with insulation sandwiched between
plywood or OSB sheets. Wall panels are assembled in the eld.
n
By providing a continuous insulation/thermal barrier at the building exterior, SIPs
ensure minimal thermal bridging and avoid gaps, voids or compression often
found in standard cavity insulation installations.
n
Installation requires detailed joint sealing and proper water- and weather-
resistive barriers.
82
EXTERIOR WALLS
Insulated Concrete Forms (ICF)
IFCs are factory-made forms constructed from rigid
insulation boards designed to be assembled onsite and
lled with concrete.
n
Steel reinforcement and concrete poured into the voids result in an airtight,
well insulated, sturdy wall.
n
Continuous interior and exterior insulation eliminates thermal bridging, with no voids,
gaps or compression often found in standard cavity insulation installations.
n
Most typically used for foundation walls, although gaining favor for
above grade exterior walls.
n
Below- and above- grade ICFs must be protected like other board insulation to
prevent physical damage to the insulation, as well as be treated with a weather-
resistive barrier.
83
WINDOWS, DOORS, AND SKYLIGHTS
General
Windows, skylights, and doors transmit a substantial
amount of heat. Even a high performance window has
less than 15% the insulating value of a code-compliant
frame wall.
Modern glass and glazing systems are much improved over glass historically used in
residential construction.
n
Low-E-coatings, triple glazing and sealed gas between glass layers improve the
insulating qualities of glass.
n
High performance glass reduces UV (ultraviolet) radiation, benecial for energy
performance and for color protection of interior nishes and fabrics.
n
Proper installation including head and sill ashing and sealing is essential
to protect glazed units and interior and exterior nishes.
Courtesy of IBTS
84
WINDOWS, DOORS, AND SKYLIGHTS
Window Frames
Material choice and manufacturer details have a signicant
effect on window performance.
n
Wood is a better insulator (and less conductive) than metal and a good choice for
window, door and skylight frames.
n
Metal frames must have thermal breaks to stop transfer of heated or cooled air
across the assembly.
n
Most manufactured window assemblies come with a label indicating energy
performance rating by the National Fenestration Rating Council (NFRC).
85
WINDOWS, DOORS, AND SKYLIGHTS
Window Labels
The National Fenestration Rating Council (NFRC) presents independent results on four areas
of energy performance from NFRC-certied laboratories.
Understanding the NFRC Label
U-factor measures the
heat from INSIDE a
room that can escape.
The lower the number
the lower the potential
for wasted heating
expenses.
Visible Transmittance
measures how much
natural light can come
into a room -- a HIGH
number means more
natural light.
Air Leakage measures
how much air will enter a
room through the
product. The lower the
number, the lower the
potential for draft
through the product.
Solar Heat Gain
Coefficient measures
the amount of
OUTDOOR heat that can
enter a room. The lower
the number, the lower the
potential for wasted
cooling expenses.
This image mirrors the four sections of the certified NFRC Label, providing the consumer with visual
illustrations of what the label ratings mean. More in-depth information on the NFRC Label and
purchasing the best possible windows, visit www.WindowRatings.org
NOTE
• For additional information, see websites of the American Architectural Manufacturers Association
(AAMA) and the Window and Door Manufacturers Association.
Courtesy of NFRC
86
WINDOWS, DOORS, AND SKYLIGHTS
Window Installation
Always install the best performing windows possible: as
operable units, they receive much wear and tear over the
building’s lifetime. Their inherent energy inefciencies (low
thermal resistance, installed with an open perimeter until
sealed) must be compensated for with excellent and
appropriate installation techniques.
n
Perimeters are a potential source of air leakage and water intrusion. For energy
performance and durability, seal and ash properly.
Courtesy of the Department of Energy
NOTES
• See section on Housewrap: Installation at Openings, page 40.
• See Building Science Corporation, Water Management Details for Residential Buildings.
87
WINDOWS, DOORS, AND SKYLIGHTS
Door Installation
Exterior doors are a potential source of heat loss. Doors
must be properly installed with careful attention to the
sill, where water entry is most likely. Doors must be
tight when closed with all weather stripping at jambs
and threshold engaged.
88
WINDOWS, DOORS, AND SKYLIGHTS
Skylight Installation
Skylights increase the opportunity for a space to benet
from natural daylight. However, they are vulnerable to water
inltration and must be properly ashed and sealed. Walls
framing the skylight must be insulated as part of the
building thermal envelope.
Manufacturers’ roof mounted
ashing or fabricated curb
89
FLOORS
Separating Conditioned
and Unconditioned Spaces
Floors between conditioned and unconditioned spaces,
such as between a garage and second oor bedroom, are
part of the building thermal envelope.
n The entire oor cavity must be lled to full depth with insulation that is held in place
with netting, wood, wire, staples, etc. To be effective, insulation must stay in contact
with the warm surface.
n
The wall between the garage and the house, and the ceiling above it that may be
below the house, should be air sealed as with all exterior walls, and to protect
building occupants from the products of combustion or entry of other airborne
pollutants from the garage. After parking and turning off the car motor, timed
mechanical ventilation of garage can provide additional protection from potential
movement of carbon monoxide into the home.
Conditioned/Living Space
Unconditioned Garage
Ceiling insulation
secured and
protected by
sheetrock
Securely attach
insulation with
netting, wire, strip
or other means
Unconditioned
basement
90
FLOORS
Cantilevered
Floors cantilevered over outside air, such as over an open
carport or porch, are part of the building thermal envelope.
n Insulation must be continuous and maintain permanent and complete contact with
the oor of the conditioned space above.
Weather exposed facing
Conditioned Space
Conditioned Space
Outside Space
Wood blocking
at inside face of
exterior wall
91
FLOORS
Level Changes
Floors and their vertical connections exposed to outside
air or unconditioned space in split level houses must
be insulated and air sealed as part of the building
thermal envelope.
Conditioned Space
Unconditioned Space
Unconditioned
Crawl space
92
ATTICS AND ROOFS
Vented Attics
General
While attics are traditionally vented, unvented attics have
many advantages. Codes allow for both options.
In a vented attic, the building thermal
envelope is located at the attic oor/
ceiling of the conditioned space below
and must be insulated and fully air sealed.
Ventilation is provided at softs, roof
ridges, knee walls, and /or vertical walls.
n
In winter:
Maintains cold roof temperature to
control ice dams created by melting
snow if the ceiling below
is completely air sealed.
n
In summer:
Natural ventilation provides opportunity for moisture removal.
Vented attic disadvantages:
n
Ductwork and mechanical equipment
must be insulated.
n
Access doors to attic through ceiling
below must be airtight and sealed.
n
Soft and other vented attic details
(blocking, venting, sealing, insulation
depth and location) are often done
wrong and create problems, primarily
at the roof edge.
n
Can increase air leakage if not fully
air sealed.
93
ATTICS AND ROOFS
Vented Attics
Loose Fill (or Batt) Insulation
Vent-chute
Gasket
Roof vent
Flue
or vent
Mechanical
equipment
Insulated mechanical
equipment and ductwork
Roof bafe installed
at each bay
Access Hatch
Rigid barrier to
contain insulation
Rigid insulation (
+
/
-
4”) adhered to
plywood or other hatch material
Gasket
Access hatch
Wind bafe installed
to protect insulation
from disturbance
(wind washing)
Unconditioned Attic
Vented Attics
Pull-Down Ladder
94
ATTICS AND ROOFS
Full-Height Door Access
Rigid barrier to
contain insulation
Pull-down ladder
Weatherstrip
around opening
Rigid insulation (
+
/
-
4”)
adhered to top and
sides of hinged
plywood cover or cap
Door latch/hardware
for tight t
Rigid foam insulation adhered to
attic side of door
Weatherstrip around full opening
Threshold/door sweep
Insulation to
ceiling level
R-value
Insulation to wall
level R-value
95
ATTICS AND ROOFS
Unvented Attics
General
Insulating the roof and eliminating ventilation
brings an attic into the conditioned space.
Unvented attic advantages:
n
Increases a home’s livable space.
n
Mechanical equipment located in the attic may not require insulation.
n
May be preferable to vented attics in complex roofs.
n
Temperature and humidity can be controlled.
Unvented attic disadvantages:
n
Hotter in summer than vented attics, causing an increase in cooling demand.
n
More difcult to see or trace (future) roof leaks.
96
ATTICS AND ROOFS
Unvented Attics
Spray Foam Roof Insulation
Fiberglass Batts and
Rigid Board Insulation
Flue
Conditioned Attic
Mechanical
equipment
Flue
Rigid insulation
Roof deck
Conditioned Attic
Mechanical
equipment
Provide dams or other
methods to keep foam
clear of heat source as
required by code
Sealed ducts
Provide dams or other
methods to keep foam
clear of heat source as
required by code
Sealed ducts
Sealant
97
ATTICS AND ROOFS
Knee Wall Access Door
Door latch/hardware
for tight t
Rigid foam insulation adhered
to door matching R-value
of knee wall insulation
Weatherstrip around
full opening
Wood stop behind
Threshold/door sweep
Unconditioned
Space
Roof bafe
installed each bay
Soft vent
Knee wall
Unvented Attics
Knee Walls
n
Low knee walls provide
vertical surfaces in attic
that increase space
usability and may facilitate
the continuity of the
building thermal envelope.
98
SUNROOMS
General
Sunrooms are specically dened by code as one-story
structures attached to the home with glazing (windows,
skylights, and/or doors) covering more than 40% of the area
of the exterior walls and roof.
n
Sunrooms that are heated or cooled, do not exceed 500 sf, and are thermally isolated
from the rest of the home are permitted to have reduced R-values at walls and ceiling.
n
Walls, doors, and any windows separating the sunroom from the home are treated as
exterior and must meet the building thermal requirements of the code.
n
Mechanical systems for heating or cooling should be separately zoned.
BUILDING
SYSTEMS
Heating and Cooling ......................99-106
Conditioned Spaces;
Heating and Cooling ........................... 99
Boilers
.................................................. 100
Furnaces
............................................... 101
Heat Pumps
.......................................... 102
Cooling
................................................. 103
Programmable Thermostats
................. 104
Duct Sealing
......................................... 105
Duct Insulation
..................................... 106
Ventilation
.....................................107-112
Natural Ventilation
................................ 107
Mechanical Ventilation;
General ............................................. 108
Whole-House Ventilation: Exhaust ... 109
Whole-House Ventilation: Supply ..... 110
Whole-House Ventilation:
Balanced Systems ............................ 111
Heat Recovery Ventilation (HRV) and
Energy Recovery Ventilation (ERV) ... 112
Domestic Hot Water
....................113-116
Hot Water Heaters;
Storage ............................................. 113
Tankless (Instantaneous) ................... 114
Tankless Coil (Indirect) ..................... 115
Insulation .......................................... 116
Pipe Insulation .................................. 116
Plumbing Fixtures
and Appliances
............................117-118
Plumbing Fixtures
................................. 117
Appliances
............................................ 118
Lighting / Electrical
.....................119-125
Interior Lighting
.................................... 119
Interior Lighting Controls
...................... 120
Interior Lamps;
Bulbs ................................................. 121
Comparing Bulbs .............................. 122
Exterior Lighting
................................... 123
Snow and Ice Melt Systems
................. 124
Pool Heaters
......................................... 125
Building Systems
BUILDING
SYSTEMS
Illustration Key
Batt insulation
Foam insulation
Loose ll insulation
Rigid foam insulation
Sheathing (plywood, OSB)
Control layer (air, vapor, moisture)
Sealant (continuous)
Gypsum board
(wall or ceiling)
Wood blocking
Concrete
Gravel
Siding
99
HEATING AND COOLING
Conditioned Spaces
Heating and Cooling
The most energy efcient heating system will only save
money when properly installed and maintained. Installations
should conform to the latest version of ACCA 5 HVAC
Quality Installation Specication.
n
Properly sized and installed systems provide steady, even and energy efcient
heating/cooling. Right-sizing permits a building’s system to be based on the rate at
which the building is predicted to lose heat.
n
Oversized units quickly meet thermostat set points and then shut down. This short
cycling, which uses more energy, wears out components and creates excess noise.
n
Heating and cooling equipment typically is designed in accordance with the latest
versions of ACCA Manual J (building loads) and Manual D (duct design), as required
by code. ACCA Manual S (equipment sizing) and Manual T (air distribution) also help
ensure properly designed systems.
n
Proper installation, system commissioning, testing and customer education are the
best assurances for energy efciency and occupant safety. Testing ensures that all
equipment, connections, ues, ducts and other associated items are tightly sealed
for energy efciency and occupant safety.
n
Code may require ventilation and/or makeup air for combustion and to prevent
backdrafting of gas appliances.
Common fuel types:
Natural gas:
n
Clean and economical.
n
Direct utility connection.
n
Not available in all areas.
Oil:
n
Although costs uctuate, less
expensive than LP but more expensive
than natural gas.
n
Does not burn as cleanly as gas, thus
requiring yearly maintenance.
Liquid Propane (LP):
n
Clean burning.
n
Requires delivery and storage.
n
Costly.
Wood:
n
Not available for use in all areas.
n
Quality and maintained stoves, proper
ventilation, and sustainably harvested
wood are essential. Flue must be
properly sized and outside combustion
air may be required.
NOTE
• Mechanical ventilation is critical in tight buildings for life safety, building protection,
and proper operation of equipment.
100
HEATING AND COOLING
Boilers
n
Typically used to produce hot water (or steam) which is distributed via piping and
radiators to create heat (hydronic system). Can also be used with a ducted system
via the installation of a hydronic heating coil, and to produce domestic hot water.
n
Fuel sources: typically gas or oil; some wood boilers used, typically in rural areas.
n
ENERGY STAR
®
boilers with AFUE ratings 85% or greater use about 6% less energy
than standard boilers. These have new combustion technology which extracts more
heat from the same amount of fuel.
n
Condensing boilers: convert latent heat from water vapor into condensing gases
instead of losing it to atmosphere. Flue gases are used to preheat water returning
to the boiler. Generally work best with low temperature heat sources.
n
Non-condensing boilers are less expensive and require venting into a chimney.
n
High efciency sealed-combustion boilers use outside air to fuel the burner without
relying on a chimney draft to vent. In particular, in buildings with tighter thermal
envelopes, these boilers reduce unwanted interior drafts and are safer since not
subject to backdrafting. No chimney is required.
101
HEATING AND COOLING
Furnaces
n
Fuel Source: typically gas or oil; some wood
furnaces used, typically in rural areas.
n
ENERGY STAR
®
furnaces with AFUE ratings 85%
or greater use about 15% less energy than standard
furnaces.
n
Condensing gas furnaces can vent directly to the
outside with PVC pipe, versus a lined masonry
chimney.
n
A two stage furnace operates most of the time on a
lower burner setting. Variable speed blower motors
are more expensive but operate more efciently
and have an auxiliary terminal for air cleaner,
dehumidication and multistage air conditioning
without the need for separate controls.
n
Hot air systems typically use some ductwork for heating and cooling.
Ductwork must be sealed throughout the house and insulated if it is located
in unconditioned spaces.
n
High efciency sealed-combustion furnaces use outside air to fuel the burner without
relying on a chimney draft to vent. In particular, in buildings with tighter thermal
envelopes, these boilers reduce unwanted interior drafts and are safer since not
subject to backdrafting. No chimney is required.
102
HEATING AND COOLING
Heat Pumps
Heat pump systems are used for heating, cooling, and/or
producing heated water. Some systems can accomplish
all, and/or be used in combination with other heating/
cooling equipment (e.g., used with conventional storage
water heater).
n
Although heat pumps have higher initial costs, operating costs can be reduced
15% - 25%. Geothermal heat pumps are typically more efcient than air source heat
pumps, although more costly to install.
n
Because of limited output in extremely cold weather, heat pumps typically have a
back-up heating system (electric strip heating or furnace).
Two primary types of heat pumps:
Air Source Heat Pumps:
n
Mini-splits. System that incorporates ductless fan coils, most often wall mounted,
to condition individual rooms. Multiple indoor fan coils can be used with on outdoor
unit. Typically use inverter-driven technology which allows for variable capacity and
very high efciency equipment.
n
Ducted mini-splits. Compact systems that use short, low-friction duct runs to deliver
air to 1-3 rooms. Multiple indoor fan coils can be used with a single outdoor unit.
Typically use inverter-driven technology.
n
Central Ducted. System that delivers air to an entire home using a single air handler
and a conventional duct system with supply and return ducts. Inverter-driven
technology is available only from a limited number of manufacturers.
Geothermal Heat Pumps:
n
Closed loop. Circulates an antifreeze and/or water solution through a closed loop
(typically plastic tubing) buried in the ground vertically or horizontally or submerged in
water (pond or lake).
n
Open loop. Uses well or surface body water as the heat exchange uid that
circulates directly through the heat pump and returns the uid back to the source.
n
Direct exchange. Refrigerant in ground loops (copper pipes) used to transfer
the heat.
103
HEATING AND COOLING
Cooling
Cooling technologies include ventilation, air conditioning,
evaporative and absorption cooling, and radiant cooling.
Equipment varies greatly in quality and energy efciency,
and maintenance is essential to maximize performance
and efciency. Proper siting, deciduous vegetation and
natural ventilation are also planning techniques that can
minimize cooling loads.
n
Central air conditioners circulate cool air from the air conditioner through supply
ducts located throughout the building. As cooled air is warmed, it is circulated back
to the air conditioner through return ducts and registers. Equipment includes outdoor
compressors or condensers connected to an indoor air-handling unit.
n
Ductless, mini-split systems, like central air conditioners, have outdoor compressors
or condensers and an indoor air-handling unit. These are often used in buildings with
non-ducted heating systems (i.e., hydronic heating). Systems are available with a
single outdoor unit and multiple indoor heads for zoning applications.
n
Other technologies (evaporative cooling in dry climates; absorption).
104
HEATING AND COOLING
Programmable Thermostats
Proper use of a programmable thermostat, as required by
code, can save up to 25% of heating costs.
Three primary types, each with four temperature settings per day:
7 day model:
n
For schedules that change daily.
5 + 2 day model:
n
Same weekday schedule and another for weekends.
5 + 1 + 1 day model:
n
Same weekday schedule, separate schedules for Saturday and Sunday.
105
HEATING AND COOLING
Duct Sealing
Properly sealed duct systems can save energy, improve
occupant comfort and increase the life of heating and
cooling systems.
n
Seal all joints, connections, collars, sleeves, boots, elbows, supply/return registers,
and other components of the system.
n
Seal all penetrations in building thermal envelope where ductwork transitions from
conditioned space to unconditioned space (e.g., ductwork that runs through an
unconditioned attic into a bedroom).
n
Use UL181A or 181B rated tape or duct mastic; do not use duct tape. Joints
should be held with sheet metal screws. Mastic may require berglass mesh prior
to application of mastic. Follow all manufacturer recommendations specic to
material used for ducts and mastic.
n
Standard tests are available and required by code to evaluate duct
sealing completeness.
Furnace
Seal collars
and stackheads
Seal registers
Seal
boots
Seal
elbows
Seal
joints and
connections
Seal plenum
Duct Sealing Locations
106
HEATING AND COOLING
Seal duct
seams and
openings
with UL
approved
tape or
mastic
Square cut insulation;
butt joint edges at joints
Tape all
insulation
seams with
manufacturer
approved
material
Warm Air Duct
Duct Insulation
Where possible, install duct system within the building
thermal envelope. Insulate all ducts outside the building
thermal envelope per code.
n
Properly seal duct system before insulating.
n
Cover all exposed portions of ducts with properly selected and installed insulation.
n
Tape seams and eliminate all voids.
n
Fasten with mechanical means, such as plastic straps or UL-rated metal tape, per
manufacturer instructions.
107
VENTILATION
Natural Ventilation
Well designed, natural ventilation can be the least
expensive and most energy efcient way to provide
cooling. Natural ventilation can improve indoor air quality
and maintain a healthy and comfortable indoor climate.
n
Fresh air moves through a building via pressure differences caused by prevailing
winds or the buoyancy effect created by temperature or humidity differences.
Design for natural ventilation must give equal consideration to supply and exhaust.
n
A successful ventilation design considers numerous factors for windows and doors
including type of operability (e.g., double hung versus casement window) and size
and placement of window and door openings at exterior walls.
n
To complete the airow circuit, interior features that are part of the design include
transom windows, louvers and grills, open oor plans, vertical air movement, ceiling
or window fans, and roof or upper level exhaust.
n
Because a house’s natural ventilation rate is unpredictable, ventilation may not be
uniform 100% of the time.
Courtesy of IBTS
108
VENTILATION
Mechanical Ventilation
General
Mechanical ventilation systems use ducts and fans rather
than windows, doors or vents alone to serve individual
spaces or whole houses. Individual spaces such as
bathrooms, kitchens, and laundry rooms typically use a
ceiling or wall mounted exhaust fan.
n
Provide consistent levels of comfort and air quality through controlled air movement
and removal of allergens, pollutants and moisture that can cause mold. Systems can
be supplemented with ltration and dehumidication.
n
Systems consist of single or multiple fans, ducts and equipment located at
appropriate intake and exhaust locations. Quiet, high efciency fans designed for
extended or continuous operation at source point can preclude the use of more
complicated systems.
n
Fans must be properly sized for individual spaces. ASHRAE recommendations:
n
Bathrooms
50 cfm for intermittent fans; 20 cfm for continuous ventilation.
n
Kitchens (based on room volume)
Exhaust independent of range: Continuous rate of 5 ACH min. or intermittent
rate of 100 CFM min.
Exhaust integrated with range: 5 ACH min.
Courtesy of the Department of Energy
109
VENTILATION
Mechanical Ventilation
Whole-House Ventilation: Exhaust
Exhaust ventilation systems work by depressurizing the
building. By reducing the inside air pressure, air can move
through the building via intentional paths such as windows
and vents.
n
Typically composed of a single fan connected to a centrally located, single exhaust
point in the house.
n
Advanced design connects the fan to ducts from several rooms, including kitchens,
bathrooms and laundry rooms where pollutants are generated.
n
Adjustable, passive vents through interior or exterior window or wall openings can
be installed to introduce fresh air, although may be ineffective when interior/exterior
pressure difference is inadequate.
n
Relatively simple and inexpensive to install as part of initial construction. Whole
house fans work best in colder climates. In climates with warm, humid summers,
depressurizing can draw moist air into building wall cavities where condensation
and moisture damage may occur and cause gas applicance backdrafting.
Exhaust air outlet
Air ow
Air inltration
Positive air pressure
Negative air pressure
Central exhaust fan
Exhaust Ventilation
110
VENTILATION
Mechanical Ventilation
Whole-House Ventilation: Supply
Supply ventilation systems work by positively pressurizing
the building.
n
Fan and duct system introduce fresh air into one or more rooms most often occupied
(bedrooms, living room, etc.). May include an adjustable interior or exterior window or
wall opening in other rooms.
n
Fan draws outside air into the building; air escapes through holes in the envelope,
bath and range fans and ducts, and other intentional vents.
n
Relatively simple and inexpensive to install as part of initial construction.
n
System can be enhanced to lter air to remove pollen and dust or to provide
humidity control.
n
Ideal in hot or mixed climates: may cause moisture problems in cold climates.
If excessive moisture exists in air entering the house, cooling costs may be
increased. Outdoor air may require mixing with indoor air to avoid drafts at cooler
temperatures and/or removal of moisture.
Supply Ventilation
Fresh air inlet
Central supply fan
Air ow
Air inltration
Positive air pressure
Negative air pressure
111
VENTILATION
Mechanical Ventilation
Whole-House Ventilation: Balanced Systems
Balanced ventilation systems introduce and exhaust
approximately equal quantities of fresh outside air
and inside air.
n
Balanced ventilation systems are appropriate for all climates, although are usually
more expensive to install and operate than supply or exhaust systems.
n
Balanced ventilation systems typically have two fans, two duct systems and
appropriately located exhaust vents. Distribution of fresh air is facilitated by placing
supply and exhaust vents in spaces most often occupied (bedrooms, living rooms,
etc.). Air is exhausted from rooms where most moisture and pollutants are generated
(kitchen, bathrooms and laundry). Filters can mitigate dust and pollen from outside
air before introduction into the house.
n
Unlike energy recovery ventilation systems, moisture and heat are not removed from
air before entering the house. This may contribute to higher heating and cooling
costs. Outdoor air may require mixing with indoor air before delivery to avoid drafts
at cooler temperatures.
Balanced ventilation
Exhaust air outlet
Room air exhaust ducts
Fresh air inlet
Supply fan
Air ow
Air inltration
Positive air pressure
Negative air pressure
112
VENTILATION
Mechanical Ventilation
Heat Recovery Ventilation (HRV) and
Energy Recovery Ventilation (ERV)
n
To reduce heating and cooling loads caused by outside ventilation air and provide
energy efciency, HRVs and ERVs exchange heat (sensible) and moisture (latent)
between the two airstreams.
n
HRVs exchange only heat (sensible).
n
ERVs exchange both heat (sensible) and moisture (latent).
n
To achieve balanced air ows, HRV or ERV ventilation systems have two fans:
one brings outside air into the building, and the other exhausts stale interior air.
These systems also lter incoming air, provide spot ventilation for bathrooms
(eliminating separate fans) and deliver ventilated air throughout the house.
n
HRV/ERV can be installed using an existing HVAC duct system and/or as a complete
stand alone, fully ducted system.
n
Proper design, system installation, commissioning, testing and customer education
is required.
Courtesy of DOE
113
DOMESTIC HOT WATER
Hot Water Heaters
Storage
Traditional water heaters maintain heated water in insulated
tanks at a constant temperature. High efciency units and
insulation jackets are recommended to counteract any
inherent inefciency and heat loss.
n
Traditional fuel sources for storage water heaters include natural gas, oil, propane
and electric. Heat pump storage water heaters that use electricity to transfer heat
(instead of generating heat directly) can be two to three times more energy efcient
than a conventional electric resistance water heater.
n
High efciency sealed-combustion hot water heaters use outside air to fuel the
unit. In particular, in buildings with tighter thermal envelopes, these boilers reduce
unwanted interior drafts and are safer since not subject to backdrafting.
n
Water heaters should be selected based on the Energy Factor (EF), an annual
measure of the useful energy coming out of the water heater divided by the amount
of energy used to heat the water. The higher the energy factor, the better. However,
due to varying rates for fuel sources, higher energy factor values don’t guarantee
lower annual operating costs.
n
Storage water heaters should be sized based on peak-hour demand (the busiest
one-hour) as determined by use of the GAMA Water Heater Sizing Tool. The unit’s
rst hour rating should match within 1-5 gallons of peak-hour demand.
n
Additional uses of storage hot water heaters can include providing hot water for
heating or radiant oors in small spaces, or where supplemental or back-up heat
is required.
n
Because large bathtubs/spas have a signicant impact on storage capacity,
instantaneous water heaters should be considered for these applications.
114
DOMESTIC HOT WATER
Hot Water Heaters
Tankless (Instantaneous)
Tankless or Instantaneous water heaters deliver a constant
supply of hot water on demand without standby energy
loss. These are smaller in size and more efcient than
conventional storage water heater when hot water demand
is less than 40 gallons per day. Separate units are installed
for different areas of demand.
n
Traditional fuel sources include natural gas, propane or electricity. Gas models
produce a higher ow rate than electricity, but may require a constantly burning
pilot light.
n
Initial cost is greater than conventional storage models.
n
Should be sized based on match of estimated peak-hour ow rate GPM and design
temperature rise (difference between coldest inlet water temperature and outlet water
temperature) with manufacturer rated ow rate.
Tankless (Instantaneous) Water Heater
Valve
Flow sensor
Hot water out
Heat exchanger
Burner
Fan
Gas line
Cold water in
115
DOMESTIC HOT WATER
Hot Water Heaters
Tankless Coil (Indirect)
n
Uses main furnace or boiler to heat a liquid circulated through a heat exchanger
in a storage tank.
n
When well insulated and used with a high efciency boiler or furnace, can be the
least expensive means to provide hot water.
n
Works most efciently when heating system is in use. Summer usage may not be
cost effective.
Indirect Water Heater
Boiler
Burner
Cold water inlet
Hot water outlet
Storage tank
Heat exchanger
Drain
116
DOMESTIC HOT WATER
Hot Water Heaters
Insulation
n
Hot water temperature should be maintained at 115° – 120° F.
n
Storage tanks with an integral R-value < 20 should have an
insulation blanket (jacket) to reduce standby heat loss.
n
Insulation blanket must be taped in place without compressing
or blocking the ue draft collar.
Pipe Insulation
n
Reduces heat loss and can maintain a 4° F higher water
temperature than uninsulated pipes.
n
Typically closed cell foam purchased in precut lengths;
seams must be taped.
n
Prefabricated tting insulation is best, but may be
most expensive.
n
At gas heaters, insulation must be kept away from
combustion heat per manufacturer recommendations,
approximately 6”.
117
PLUMBING FIXTURES AND APPLIANCES
Plumbing Fixtures
Products with the WaterSense
®
or other energy efcient
labels often perform better and are up to 20% more
water efcient.
n
WaterSense
®
is a federal program that encourages the use of water and energy
efcient products, including bathroom sink faucets and accessories, showerheads
and other accessories or equipment.
n
The average household could save more than 2,300 gallons per year by installing
WaterSense
®
labeled showerheads alone, as well as reduce operational demands on
water heaters.
118
PLUMBING FIXTURES AND APPLIANCES
Appliances
ENERGY STAR
®
qualied appliances incorporate advanced
technologies and use 10 – 50% less energy than standard
appliances. Every appliance is labeled to indicate purchase
and operational costs.
ENERGY STAR
®
is a joint program of the U.S. Environmental
Protection Agency and the U.S. Department of Energy.
n Refrigerators and freezers:
ENERGY STAR
®
qualied refrigerators use up to 40% less energy
than conventional models.
n Dishwashers:
ENERGY STAR
®
qualied dishwashers use at least 40% less energy
than the federal minimum standard for energy consumption.
n Clothes washers:
ENERGY STAR
®
qualied clothes washers use up to 50% less energy
and 55% less water than standard washers.
119
LIGHTING / ELECTRICAL
Interior Lighting
Energy (kWh) = power (kilowatts) x time (hours).
Given the great opportunity to save energy through the
selection and location of lighting equipment, codes
specically establish which xtures and lamps are
minimally acceptable. There are several ways to reduce
energy used for lighting purposes:
n
Use energy-efcient xtures and lamps.
n
Select and lay out lighting xtures to maximize task (vs. general) lighting.
n
Locate windows to maximize daylight.
n
Use occupancy sensors to control xtures automatically.
Courtesy of the Lighting Research Center
120
LIGHTING / ELECTRICAL
Interior Lighting Controls
People are good at turning lights on when they
enter a room but less reliable in turning lights off
when they leave.
n Occupancy Sensors:
Ceiling or wall mounted units turn lights on or off based on detected movement
in a room.
n
Manual on/auto-off (Vacancy) Sensors:
Occupants must turn lights on manually on entering a space; lights turn off
automatically when no motion is detected.
n
Dimming Switches:
Provide energy savings by giving occupants control over light output in a room
versus a standard switch. Dimmers may not be compatible with all xtures, with
particular concern given to CFLs.
121
LIGHTING / ELECTRICAL
Interior Lamps
Bulbs
Homes will soon be required to have at least 75% of the
lamps in permanently installed lighting xtures be high-
efcacy lamps, although this does not require the use of
low-voltage lighting.
Cost savings:
n
An ENERGY STAR
®
qualied compact uorescent light bulb (CFL) uses about 75%
less energy than a comparable standard incandescent bulb. Replacing a 60-watt
incandescent with a 13-watt CFL can save more than $30 in energy costs over the
life of the bulb.
n
Compared to standard incandescent bulbs, ENERGY STAR
®
qualied CFLs
generate about 75% less heat. They are cool to the touch and can help
reduce home cooling costs.
n
When comparing bulb types, the higher efcacy bulb may not always be the
best choice or even the most efcient. Factors including color and temperature
should be considered.
n
Rapid advances in code requirements and manufactured products ensure an
increased use of energy efcient bulbs in residential construction.
Incandescent Compact
uorescent
LED Metal halide Linear
Fluorescent
122
LIGHTING / ELECTRICAL
Interior Lamps
Comparing Bulbs
Efcacy, or lumens per watt, is an indication of a bulb’s
efciency. High efcacy bulbs may have unacceptable color
rendering, a measure of how colors are represented.
0 20 40 60 80 100 120 140
High Pressure Sodium
Metal Halide
Compact Metal Halide
Linear Fluorescent
Compact Fluorescent
Light Emitting Diode (LED)
Infrared Halogen
Halogen
Incandescent
Maintained Efcacy (Lumens/Watts)
123
LIGHTING / ELECTRICAL
Exterior Lighting
Lighting gardens, driveways, walkways and entry doors
is important for safety and aesthetics. However, too
much lighting or lighting in the wrong locations wastes
energy and causes “light pollution.”
Exterior lamps should be either:
n
Low voltage.
n
High efciency xtures or lamps.
n
Photovoltaic.
Exterior lighting should be controlled using either:
n
Timeswitch control.
n
Photosensor.
Courtesy of the Lighting Research Center
124
LIGHTING / ELECTRICAL
Snow and Ice Melt Systems
Snow and ice melt systems are used to remove snow and
ice from walkways, driveways and roof eaves via embedded
electric cables or hydronic piping.
Snow melt systems should be equipped with controls that are either:
n
Automatic shutoff when the pavement temperature is above 50º F degrees and no
precipitation is falling.
n
Automatic or manual shutoff when the outdoor temperature is above 40º F.
Shutoffs should be readily accessible and turned off when not needed.
Courtesy of IBTS
125
LIGHTING / ELECTRICAL
Pool Heaters
Many swimming pools located in New York State are
heated. Without proper oversight, these are a substantial
and unnecessary source of energy use.
Requirements for pool heaters include:
n
An accessible manual on-off switch to permit shutting off of heater without adjusting
the thermostat setting.
n
Time switches that automatically turn on and off heaters and pumps according to a
preset schedule, except for solar- pool heating systems.
n
Heaters red by natural gas or LPG are not permitted to have continuously burning
pilot lights.
Pools must also be equipped with a vapor-retardant cover: those heated to more than 90° F
require a cover with a minimum insulation value of R-12.
Glossary
and Index
GLOSSARY
AND INDEX
GLOSSARY
AND INDEX
127
GLOSSARY GLOSSARY
Advanced framing: Strategy for reducing
thermal bridging by minimizing wall
framing needed for structural support,
thus permitting additional insulation.
Common techniques include 2x6 inch
framing at 24 inch on-center spacing,
single top plates where trusses align with
wall framing below, insulated headers,
2 or 3-stud corners, lattice (ladder) strips
at exterior/interior wall intersections, and
the elimination of redundant re blocking
and excessive window and door framing.
Air barrier: Any material that restricts air
ow. In wall assemblies, the exterior air
barrier is often a combination of sheathing
and either building paper, housewrap, or
rigid foam insulation. The interior air barrier
may be fully sealed gypsum board.
Air changes per hour (ACH): Number
of times per hour that the air equal
to the volume of a space is changed.
ACH depends upon the efciency
of the ventilation method and the
building tightness.
Air conditioning: Process of modifying air
to meet the requirements of a conditioned
space by controlling its temperature,
humidity, purity, and distribution.
Air-impermeable insulation: See Insulation,
air-impermeable.
Alignment: Condition where the air
barrier and thermal barrier (insulation)
are contiguous (touching) and continuous
across the entire building envelope.
Ambient air: Air external to a building
or device.
Annual fuel utilization efciency (AFUE):
Measure of the amount of fuel converted
to space heat in proportion to the amount
of fuel entering the furnace, expressed as
a percentage. A furnace with an AFUE of
90 is considered to be 90% efcient.
ASHRAE: Membership organization
previously known as the American
Society of Heating, Refrigeration, and
Air-Conditioning Engineers. ASHRAE's
Standard 90.1 is a commonly used code
path applicable to residential buildings
greater than three stories in height.
Assembly: For the purposes of this
document, assembly refers to the
composite of materials used in the
building thermal envelope. For example,
an exterior wall assembly may include
gypsum board, vapor retarder, wood
framing, sealed rigid board insulation,
exterior sheathing, and exterior cladding.
Attic, vented: In an insulated building, an
unconditioned attic space insulated at the
oor level with natural ventilation typically
provided through soft and ridge vents.
Attic, unvented: In an insulated building, a
conditioned attic space insulated at the
roof level (within or above roof cavity), with
no ventilation provided to this space.
Batt insulation: See Insulation, batt.
Glossary
128
GLOSSARY GLOSSARY
Blower door test: See Envelope Air
Leakage.
Boiler: Self-contained appliance where
heat produced from the combustion of
fuels (natural gas, fuel oil, wood or coal)
is used to generate hot water, which
is circulated for space heating and/or
heating of domestic hot water.
Boiler rating: Heating capacity of a steam
boiler expressed in Btu per hour (Btu/hr),
horsepower or pounds of steam per hour.
British thermal unit (Btu): Amount of heat
(energy) required to raise the temperature
of one pound of water one degree
Fahrenheit. This is a standardized unit
of measurement to describe capacity
of heating appliances.
Building Code of New York State (BCNYS):
One in a family of codes in New York State
that establishes minimum requirements
for construction for buildings, including
residential structures greater than three
stories in height. Published by the NYS
Department of State, the BCNYS is based
on the International Building Code.
Building envelope: Components (walls,
roof, oor, and foundation) of a building
separating the inside living space from
outside elements. Unconditioned spaces,
such as an attached garage, are part of
the building envelope.
Building thermal envelope: The basement
walls, exterior walls, slab, roof, ceilings,
and/or other building components that
enclose conditioned space and serve as
the boundary between conditioned and
unconditioned space.
Building system: Combination of
equipment, components, controls,
accessories, and interconnecting means
that transforms energy to perform a
specic function, such as heating,
ventilation, air conditioning, hot water
heating, or lighting.
Cantilever: Overhang where one oor
extends beyond a wall below, exposing
the underside of the oor to exterior
conditions.
Cathedral ceiling: Finished ceiling that
follows the roof line.
Cavity: Space between inner and outer, or
upper and lower, surfaces of wall, ceiling,
oor, or roof sheathing that can be lled
with insulation to reduce heat loss.
Cellulose insulation: See Insulation,
cellulose.
Central air conditioning system: System that
provides cooling to all areas of a building
from a single appliance through a network
of ducts. May be integrated with a ducted
central heating system.
Central heating system: System that
provides heat to all areas of a building
from a single appliance through a
network of ducts or pipes. Ducted
systems may be integrated to central
air conditioning systems.
Chimney: Masonry or metal stack that
creates a draft to bring oxygen to a re
and removes the gaseous byproducts of
combustion safely out of the building.
129
GLOSSARY
Chimney Effect: See Stack effect.
Cladding: See Siding.
Climate zone: Zone that describes
exterior design conditions for a building.
New York State has three climate zones
(4, 5, and 6) which are dened in the
NY State Energy Code. Requirements
for building materials, systems, and
equipment are based upon the climate
zone in which the building is located.
Codes: Laws that regulate construction to
protect public health, safety, and welfare
and establish a minimum standard of
construction. Prescriptive codes detail
specic and mandatory requirements,
while performance codes establish a
mandatory performance level and permit
greater design exibility.
Combustion air: Air providing necessary
oxygen to appliances for combustion.
A specic quantity of air is required to
ensure complete and clean combustion.
Commissioning: A process that ensures the
as-built building, including mechanical and
electrical systems, are installed, tested
and functioning according to building
design. A commissioning report that
records the results of the commissioning
process is typically provided for above-
code energy construction projects.
Compact uorescent lamp (CFL):
Lamp that operates when
electric current is conducted
through mercury gas,
causing the phosphor-coated
glass tube of the lamp to
emit light. An alternative to
the standard incandescent
lamp (light bulb), CFLs can use one-fth to
one-third the electricity and last 8 to
15 times longer.
Compressor: Device in air conditioners,
heat pumps and refrigerators that
pressurizes refrigerant, enabling it to
ow through the system.
Condensate: Liquid that separates from
a gas due to a reduction in temperature,
such as water that condenses from ue
gases or air circulating through the
cooling coils in an air conditioning unit.
Condensation: Water droplets formed on
a surface when humid air encounters
a cooler surface. Condensation is
undesirable because it can encourage
mold growth and create a desirable
microclimate for insects.
Condenser: Device in air conditioners
or heat pumps in which the refrigerant
condenses from a gas to a liquid when it
is depressurized or cooled.
Conditioned space: Interior space within
the building thermal envelope that is
insulated and heated or cooled (new
construction).
130
GLOSSARY
Conductivity: Measure of a material's
ability to conduct heat. Materials of low
thermal conductivity are used for thermal
insulation because heat transfer across
materials of low thermal conductivity
occurs at a lower (more desirable)
rate than across materials of high
thermal conductivity.
Construction documents: Drawings and
specications, typically prepared by
an architect or engineer, that describe
construction requirements for a building.
Construction documents are a part of
required submittals for obtaining a
building permit from the municipal
building department.
Convective air ow: Air ow that occurs
in gaps between insulation and the air
barrier due to temperature and pressure
differential in and across the gap. Occurs
at locations of thermal bypass, resulting in
energy inefcient heat loss or gain.
Crawl space: An area under a building
not high enough to walk under, which
may be used for passage of building
system components.
Department of Energy (DOE): Federal
agency that provides technical information
and a scientic and educational foundation
for technology, policy, and leadership to
achieve energy efciency, diversity in energy
sources, a productive and competitive
economy, improved environmental quality,
and a secure national defense.
Dense packed insulation: See Insulation,
dense packed.
Design professional: A licensed and
registered architect (RA) or professional
engineer (PE).
Dew point: Temperature at which saturated
air that can no longer hold moisture turns
water vapor into liquid water, creating
condensation on colder surface.
Direct vent: See Vent, direct.
Double-pane or double-glazed window:
Window with two layers (panes or glazing)
of glass separated by an air space that
is typically hermetically sealed and lled
with gaseous material to improve thermal
resistance. The thermal resistance of a
window is identied by its U-factor.
Door assembly: Includes the door, hinges,
frame, and saddle. The thermal resistance
of the door assembly is identied by
its U-factor.
Door sweep: Metal or plastic strip typically
with vinyl, felt-back, or foam applied to the
bottom of a door to reduce air inltration.
Also referred to as weather-stripping.
Ducts: Conduits for distribution of heated
or cooled air in buildings, usually round
or rectangular in shape, constructed of
sheet metal, berglass board or a exible
plastic-and-wire composite located within
a wall, attic, oor or ceiling, or exposed.
Ducts outside conditioned spaces
require insulation.
131
GLOSSARY
Duct pressurization leakage: Diagnostic tool
designed to measure the
air tightness of ductwork
and to help locate
leaks. Duct leakage can
increase heating and
cooling costs up to 30%
and adversely affect
occupant comfort, health
and safety.
Duct return: Duct(s) through which heated
or cooled air passes on its way back from
the conditioned space to the heating or
cooling unit.
Duct supply: Duct(s) through which heated
or cooled air passes on its way to the
conditioned space from the heating or
cooling unit.
Duct system: Continuous passageway to
transmit heated or cooled air in a building.
In addition to ducts, the duct system
includes duct ttings, dampers, fans,
and accessory air-handling equipment
and appliances.
ECCCNYS: Energy Conservation
Construction Code of New York State.
See Energy Code.
Economizer, air: Duct and damper
arrangement and automatic control
system that allows a cooling system to
use outside air to reduce or eliminate the
need for mechanical cooling during mild
or cold weather.
Economizer, water: Component of a cooling
system that permits supply air to be
cooled by indirect contact with water that
has been cooled (by heat or mass transfer
to the environment) without the use of
mechanical cooling.
EDPM (ethylene propylene diene monomer):
Synthetic rubber membrane used for low
slope roof applications and, on a limited
basis, for vapor barriers at crawl
space locations.
Energy (use): Quantity of onsite electricity,
gas or other fuel required by building
equipment to meet building heating,
cooling, lighting, hot water, and other
loads including refrigeration, cooking,
and plug loads.
Energy audit: Inventory and descriptive
record of features, undertaken by an
energy professional, impacting energy
use in a building. This includes but
is not limited to: building component
descriptions (locations, areas,
orientations, construction attributes,
and energy transfer characteristics);
energy using equipment and appliance
descriptions (use, make, model, capacity,
efciency, and fuel type); and any
additional energy features.
Energy Code (Energy Conservation
Construction Code of New York State,
ECCCNYS): One in a family of codes in
New York State that establishes minimum
energy conservation requirements for
all buildings. Published by the NYS
Department of State, the Energy Code
is based on the International Energy
Conservation Construction Code.
132
GLOSSARY
EnergyGuide labels: Labels placed on
appliances that permit comparison of
energy efciency and energy consumption.
Energy rater: See HERS and HERS score.
Energy recovery ventilation system (ERV):
Systems that employ air-to-air heat
exchangers to recover energy from
exhaust air for the purpose of preheating,
precooling, humidifying or dehumidifying
outdoor ventilation air prior to supplying
the air to a space, either directly or as
part of an HVAC system.
ENERGY STAR
®
Home: A home that is
documented to meet a prescribed
standard more energy efcient than homes
constructed to minimum code. ENERGY
STAR
®
is trademarked by the U.S.
Environmental Protection Agency.
Envelope Air Leakage: Diagnostic tool
designed to measure the air tightness of
buildings and to help locate air leakage
points. Air tightness is a code requirement
for residential buildings in New York State.
EPA Indoor airPLUS
®
specications:
Construction specications from the
U.S. Environmental Protection Agency
for moisture control systems; heating,
ventilating, and air conditioning systems;
combustion venting systems; radon
resistant construction; and low-emitting
building materials.
EPA WaterSense
®
: Program from the
U.S. Environmental Protection Agency
to promote water efciency through
water efcient products, programs, and
practices.
Exltration: Uncontrolled outward ow of
air from a building through unintentional
gaps, voids or cracks in the building
envelope caused by wind, inside and
outside pressure, and temperature
differences and/or imbalanced supply and
exhaust airow rates. Exltration is likely to
occur at points of intersection of framing
and sheathing members, at perimeters of
windows and doors and at penetrations.
Exhaust air: Air discharged from a
conditioned space to the outside of
a building either by mechanical or
natural ventilation.
Fenestration: Window and door openings
in the building envelope.
Fiberglass insulation: See Insulation,
berglass.
Flash and batt: See Insulation,
ash and batt.
Floating slab: See Slab, oating.
Flue: Metal or masonry passageway
from heating appliances used to contain
combustion gases until they are emitted
to the building exterior.
Foam Insulation: See Insulation,
spray foam.
Forced ventilation: See Ventilation,
mechanical.
Freeze-Thaw Cycle: In buildings, the
cycle of water freezing and thawing.
Water expansion on freezing can cause
permanent damage to building materials,
in particular masonry.
133
GLOSSARY
FSK radiant barrier: Foil-coated insulation
providing re protection, commonly used
in high heat areas of a building such as
behind replaces. FSK stands for the
foil, scrim, and kraft components
of the material.
Geothermal heat pump: See Heat pump,
geothermal/ground source.
Glazing: Material, usually exible, to
cushion and seal glass against the
window or door stop and frame.
Heat gain: Increase in temperature of a
space due to conduction, convection or
radiation, typically desirable for winter
(heating) and undesirable for summer
(cooling).
Heat load: Quantity of heat added to or
removed from the building (or hot water
tank) in order to maintain temperatures at
a specied thermostat setting.
Heat loss: Decrease in temperature of a
space due to conduction, convection or
radiation.
Heat pump: Device used for heating,
cooling (in reverse mode) and water
heating that primarily uses energy from
the external environment.
Heat pump, air-to-air: Type of electrically
driven heat pump that transfers heat
from outdoor to indoor air where it is
used for heating and cooling (in reverse
mode). Air-to-air heat pumps are the
most common type used in residential
applications. Available for individual rooms
(most efcient) or as centralized, ducted
units serving more than one space. Most
are split systems with outdoor condensers
and indoor air handlers and evaporators.
Heat pump, air-to-water: Type of electrically
driven heat pump that transfers heat from
outdoor air to the indoors where it is used
for heating and cooling (in reverse mode).
Available for individual rooms (most
efcient) or as centralized, ducted units
serving more than one space. Most are
split systems with outdoor condensers
and indoor air handlers and evaporators.
Heat pump, geothermal/ground source:
Type of electrically driven heat pump that
transfers heat collected from the ground
(via circulated water in buried pipe) to the
indoors where it is used for heating and
cooling (in reverse mode). The ground
acts as both a heat source and heat sink.
Typically more efcient and expensive
than air-to-air heat pumps. Also known as
closed-loop or ground-coupled systems.
Heat pump, geothermal/water source:
Type of electrically driven heat pump that
transfers heat collected from groundwater
wells (via circulated water in buried pipe)
to the indoors where it is used for
heating and cooling (in reverse mode).
The groundwater acts as both a heat
source and heat sink. Typically more
efcient and expensive than air-to-air
heat pumps. Also known as open-loop
or groundwater systems.
Heat recovery ventilator (HRV): Energy
efciency device that captures the heat
from a building's exhaust air to preheat
air entering the mechanical ventilation
system or the fresh air supply.
Heat trap: Arrangement of piping and
ttings or a commercially available
manufactured unit that prevents
thermosiphoning of hot water during
standby periods.
134
GLOSSARY
HERS (Home Energy Rating System):
Standardized system developed by the
Residential Energy Services Network
(RESNET) to rate the energy efciency of a
home. HERS rating may establish eligibility
for programs (e.g., ENERGY STAR
®
) or, in
some communities, code compliance.
HERS score: Value between 0 and 100
that indicates the relative energy efciency
of a given home compared with the
user dened Reference Home. The lower
the score, the more efcient the home.
High efciency lamps: Compact
uorescent lamps and other emerging
new technologies with greater efcacy
than traditional incandescent lamps.
Housewrap: Pliable fabric used for
wrapping the exterior of the building
envelope to provide a water resistant
barrier between the exterior cladding and
sheathing material. When fully sealed, may
also serve as an air barrier. Wraps vary by
material, permeability and manufacturer
installation requirements.
HSPF (Heating Season Performance Factor):
A measure in Btu/Wh of total seasonal
electric power input in watt hours of
the seasonal efciency of an electric
heat pump.
HVAC (Heating, Ventilation, and Air-
Conditioning): Term used to describe
building trades or elements associated
with mechanical systems.
Hydronic system: Heating system that
uses water instead of air as the heat
transfer medium.
IAQ: See Indoor air quality
IC: See insulated contact lighting xture.
Impervious material: Ground covering, or
surface or building material that absorbs
little water. Can benet or detract from a
site's need for water run-off and collection.
Impervious soil may create adverse
conditions for sub-grade tree roots.
Incandescent: Lights using an electrically
heated lament to produce light in
a vacuum or inert gas-lled bulb.
Largely phased out in favor of high
efciency lamps.
Indoor air quality (IAQ): Quality of air within
a building that affects the health and
comfort of occupants.
Inltration: Uncontrolled inward ow of
air into a building through unintentional
gaps, voids or cracks in the building
envelope caused by wind, temperature,
and pressure differentials between inside
and outside and/or imbalanced supply and
exhaust airow rates. Inltration is likely to
occur at points of intersection of framing
and sheathing members, at perimeters of
windows and doors, and at penetrations.
135
GLOSSARY
Infrared thermal imaging (IFR): Images
taken by a heat-
sensing camera
that reveal missing
or improperly
installed insulation
including thermal
bypass conditions at voids and openings
that allow unintended thermal, air, and
moisture movement. The thermal image
graphically distinguishes between hot and
cold surface temperatures.
Insulated concrete forms (ICFs): Factory
made wall or foundation system
comprised of interlocking empty blocks
intended to be lled onsite with concrete
and steel reinforcement. ICFs create an
air-tight, well-insulated and sturdy system
with insulation inherently aligned with the
interior and exterior air barriers.
Insulated contact lighting xture (IC): Rating
for recessed light xtures that can be
installed in insulated cavities with direct
contact with insulation.
Insulation (thermal): Materials which
prevent or slow down the transfer of heat.
Insulation, air-impermeable: Insulation
which provides thermal resistance and an
air barrier when installed properly. Air-
impermeable insulation (typically foam)
is commonly used to insulate roofs in
unvented attics.
Insulation, batt: Insulation available in batts
(or rolls) sized for typical wall, oor and
ceiling framing bays that can be manually
tted into place. Typical materials are
berglass, cellulose, mineral (rock or slag)
wool and plastic and natural bers. Also
known as blanket insulation.
Insulation, blanket: Pre-cut layer of
insulation applied around a water heater
storage tank or other appliance to reduce
heat loss from the tank. Also used in
reference to batt insulation.
Insulation, blown-in: Insulation made from
berglass, cellulose, mineral wool, or
other materials that is blown dry or wet
into construction assemblies. Blown-in
insulation lls the entire framed assembly
without gaps, voids, compression, or
misalignment. Term typically excludes
spray foam insulation, which uses
alternate equipment to blow in
plastic foam materials.
Insulation, cellulose: Type of insulation
composed of recycled newspaper,
cardboard or other forms of paper.
Available as batts, loose ll, or blown-in
(damp or dry spray), including dense-
pack. A separate vapor retarder is typically
required on the interior unless the exterior
sheathing or siding is impermeable.
Insulation, dense packed: The process of
completely lling a building cavity with
blown-in insulation material, such as
cellulose or berglass, creating a densely
insulated space free of voids. Common in
the retrot of existing buildings, this can
also be used in new construction.
136
GLOSSARY
Insulation, berglass: Type of insulation,
composed of small diameter glass bers,
formed into blankets or batts, or used in
loose-ll and blown-in applications.
Insulation, ash and batt: Insulation method
for exterior walls where cavities are lled
with a combination of spray foam and batt
insulation. Using higher R-value and air
sealing foam creates a better building, and
using less expensive batt insulation at the
interior face of the cavity saves money.
Insulation, foam: High R-value insulation
product made from a variety of plastic
materials (polyurethane, polystyrene,
extruded polystyrene, expanded
polystyrene, polyisocyanurate). Available
in boards or spray onto roofs, oors, rim
joists, and gaps such as at penetrations
and window and door frames. A less
common application is injection into
closed wall or oor cavities. R-value,
expansion rates, permeability, and setting
times vary by material.
Insulation, loose ll: Insulation made from
berglass, cellulose, or other materials
composed of loose bers or granules,
which can be applied by pouring directly
from the bag or with a blower unit.
Insulation, rigid board: Plastic foam
insulation product, pressed or extruded;
typically used as insulation for interior
basement or crawl space walls, beneath
basement or crawl space slabs, and at
exterior below-grade or above-grade
walls. Panel dimensions and thicknesses
vary. R-values typically range from 3.2 to
7 per inch. At exterior walls, it can provide
contiguous insulation that creates the
building thermal envelope (foundation,
exterior walls, and roof).
Insulation, spray foam: Foam insulation
(open cell/low density or closed cell/
high density) for spray application and/or
injection into closed cavities. Installation
includes mixing of polyurethane resin
with a blowing agent using specialized
equipment, causing foam to expand to ll
cavity and encapsulate tiny gas cavities.
Must be separated from the interior of a
building by an approved thermal barrier
or approved nish material unless rated for
exposure. A less common application is
injection into closed wall or oor cavities.
Insulation, spray foam-open cell: Open
or low density foam (approximately
.5 lb/ft
3
) that is sprayed or injected.
R-value approximately 3.6 per inch.
One advantage of open cell spray foam
is that alternate blowing agents with
less adverse environmental impact and
greater durability are available. Considered
an air barrier. when minimum thickness is
5 inches.
Insulation, spray foam-closed cell: Closed
or high density foam (approximately
2.0 lb/ft
3
) that is sprayed or injected.
R-value approximately 6.0/inch, although
decreases over time as air replaces
hydrocarbon gas used as the blowing
agent. Considered an air barrier; has good
adhesion and structural strength.
Light pollution: Excessive articial light
from a building site that exceeds occupant
needs and produces glare.
137
GLOSSARY
Low-E coating: A thin, metallic oxide
coating for high performance glass (“E”
stands for emissivity or radiated heat
ow) that increases the U-factor of a
fenestration product by reducing heat ow.
Low-E coatings allow short wavelength
solar radiation to travel through glazing but
reect back longer wavelengths of heat.
Low voltage lighting: Lighting equipment
powered through a transformer such as
a cable conductor, a rail conductor, or
track lighting.
Lumen: Measurement of how much light
a lamp (bulb) creates. The more lumens
produced per watt of power, the more
efcacious (efcient) the light source.
Manual D: Standard method used to size
and design a duct system that matches
equipment blower capabilities. Published
by the Air Conditioning Contractors of
America (ACCA).
Manual J: Standard method used to
calculate residential heating and cooling
loads developed by the Air-Conditioning
and Refrigeration Institute (ARI) and
the Air Conditioning Contractors of
America (ACCA).
Manual S: Standard reference developed
by ACCA for selection of residential
equipment based on load calculations.
Includes sizing strategies and
manufacturers performance data.
Manual T: Standard reference developed
by ACCA for residential equipment for
selection, sizing and location of supply
air diffusers, grilles, and registers and
return air grilles.
Mechanical ventilation: See Ventilation,
mechanical.
Misalignment: Condition where air barrier
and thermal barrier (insulation) are not
contiguous (touching) and not continuous
across the entire building envelope.
Natural ventilation: See Ventilation, natural.
Net-zero energy building: A building that
produces as much energy as it uses over
the course of a year
Occupancy sensor: Optical, ultrasonic or
infrared sensor that turns lights or other
equipment on or off when occupancy
is detected.
Off-gassing: The evaporation of volatile
organic compounds (VOCs) from non-
metallic synthetic and natural materials.
Off-gassing, in particular for new products,
is a potential issue associated with IAQ.
Penetration: Point at which unintended air
inltration and exltration occurs between
conditioned and unconditioned spaces.
Common penetration points include,
but are not limited to, holes created for
exhaust stacks and vents, chimneys,
electrical conduit, and plumbing lines.
Performance test: An on-site measurement
of the energy performance of a building
energy feature or appliance conducted in
accordance with pre-dened testing and
measurement procedures. Should occur
prior to building occupancy.
Perm: A unit of measure of water vapor
permeance. The greater the number, the
greater the amount of water vapor that will
pass through a given material.
138
GLOSSARY
Pervious material: Ground covering, or
surface or building material, that allows the
passage of water. It can benet or detract
from waterproong and damp proong of
below-grade building components.
Phantom load: Electrical power consumed
by appliances when turned off.
Photovoltaic (PV): Method of generating
electrical power by converting solar
radiation into direct current electricity
using solar panels (solar cells containing
a photovoltaic material).
Power vent: See Ventilation, power.
Pressure boundary: The point in a building
at which inside air and outside air are
separated. Unequal interior and exterior
pressures contribute to air inltration and
exltration.
Programmable thermostat: Thermostat
that allows the user to program a pre-set
schedule of times to turn HVAC equipment
on and off.
PV: See Photovoltaic.
Radiant barrier: Thin, reective foil
sheet that exhibits low radiant energy
transmission and blocks radiant heat
transfer, usually installed in attics.
Radiant heat: Heat emitted from a warm
object, such as a oor or wall, which
warms people and objects rather than
heating the air (as in convection heating).
Exterior applications include snow melt,
gutter and roof de-icing, and patio heating.
Radon: A naturally occurring, colorless
and odorless radioactive gas that comes
from the natural decay of uranium found
in nearly all soils. Radon typically moves
up through the ground into homes through
cracks and other holes in the foundation.
A known carcinogen, radon must be
captured or prevented from entering
a house.
Rain screen: An intended space inboard
of building siding or cladding that drains
to the exterior and permits drying of the
assembly. Position, material, and detailing
vary by application.
Re-circulated air: Return air re-used as
supply air.
Registered design professional: See design
professional.
Renewable energy source: Source of energy
(excluding minerals) derived from incoming
solar radiation including natural day
lighting and photosynthetic processes,
wood, wind, waves and tides, lake or pond
thermal differences and from the internal
heat of the earth.
Residential Code (Residential Code of New
York State, RCNYS): One of a family of
codes in New York State that establishes
minimum requirements for construction of
most residential buildings not more than
three stories in height. Published by the
NYS Department of State, the RCNYS
is based on the International Residential
Code.
Rigid board insulation: See Insulation,
rigid board.
139
GLOSSARY
R-value: A measure of how well a material,
or series of materials, retards heat ow
(thermal resistance). As R-value increases,
the heat loss or gain through the material
decreases. The effective R-value of a
wall, ceiling, or oor assembly is reduced
by gaps, voids, compression, moisture,
settlement, and misalignment.
Sealed combustion: Combustion occurs in
a sealed combustion chamber using air
brought in from the outside. Combustion
products are vented to the outside through
a separate, dedicated sealed vent. Sealed
combustion with high-efciency furnaces
and boilers are the safest alternative for
increasingly airtight buildings.
Seasonal Energy Efciency Ratio (SEER):
A measurement of the seasonal cooling
efciency of an electric air conditioner
or heat pump.
Semi-permeable: Description of a
material's permeability or ability to transfer
water vapor (expressed as a numerical
value between 1 and 10 perms). Semi-
permeable materials allow water vapor to
pass through at a slow rate.
Sheathing (exterior): Construction material
used to cover the exterior of wall framing
and roof structures, not intended for long
term exterior exposure.
Siding (cladding): Material that covers the
exterior of a building envelope that is in
direct contact with outside elements. May
be wood, manufactured wood product,
cement board, or other manufactured
material including vinyl or aluminum.
Siding selection will impact choice and
location of exterior or interior air barriers
and vapor retarders.
SIPs: See Structural insulated panels.
Skylight: Fenestration located on a roof
that provides natural daylight and/or heat
and ventilation (when operable) to interior
building spaces.
Slab, oating: An economical means of
constructing a slab foundation. The slab
"oats" on a gravel base above the soil,
with thickened concrete at the edge to
hold the slab in place. Rigid insulation
can be placed between the thickened
edge and the slab to provide
slab-edge insulation.
Slab, radiant: Concrete oor slab with
integral piping or electrical conduit to
provide radiant heat.
Soft, exterior: Enclosed, horizontal
exterior area that connects lowest portion
of roof with exterior building wall.
Soft, interior: Interior area in a ceiling
that is dropped, usually to hide plumbing
or electrical services. Often found above
kitchen cabinets or bathroom showers
and bathtubs.
Solar Heat Gain Coefcient (SHGC): Measure
of how well a window or skylight blocks
the heat from sunlight. Expressed as a
number between 0 and 1, the lower the
SHGC, the less solar heat is transmitted
and the greater the energy efciency.
Solar heater, active: Solar water or space
heating system in which solar energy is
collected and/or moved from the solar
collector to a storage tank subsystem
using pumps or fans to circulate water
or heat transfer uid.
140
GLOSSARY
Solar heater, passive: Solar water or space
heating system in which solar energy is
collected and/or moved from the solar
collector to a storage tank subsystem by
natural convection without the use
of pumps or fans.
Solar power: The conversion of
sunlight into electricity using
photovoltaic materials.
Split system: An air conditioning system
that splits the hot side of the system
(condensing unit, located outside) from
the cold side (air handler, located inside).
May use ducts within the building to
circulate air.
Spray foam insulation: See Insulation,
spray foam.
Stack effect (chimney effect): The upward
movement of air through a building caused
by the normal buoyancy of warm air. As
warm air escapes through unintentional
openings high in the building, cold air is
pulled in through openings low in
the building.
Storm door: Secondary door, often glass
or plastic panels in wood, metal, or plastic
frame, used to create an insulating air
space between itself and the primary
door. Creates a secondary seal at the
exterior wall to reduce air inltration and
exltration.
Storm window: Secondary layer of glazing,
constructed of glass or plastic panel in
wood, metal or plastic frame, used to
create an insulating air space between
layers of glazing. Creates a secondary seal
at the exterior wall to reduce air inltration
and exltration.
Structural Insulated Panels (SIPs): Factory-
built insulated wall panels comprised
of insulated foam board sandwiched
between interior and exterior layers of
sheathing, typically oriented strand board
(OSB) or plywood. May be manufactured
with precut window and door openings
and conduits for electrical circuits
and piping.
Sunroom: As dened by the Energy Code,
a structure attached to a dwelling with a
glazing area exceeding 40 percent of the
gross exterior walls and roof.
Tankless water heater: Energy-efcient
water heater that heats water on demand.
Thermal barrier: Fire protection barrier
installed over foam plastic insulation.
Thermal break (barrier): Material (such
as rubber) with low thermal conductivity
placed in a construction component, such
as a window, to reduce or prevent the ow
of heat between conductive materials.
Thermal bridging: Rapid heat conduction
caused by the contact of very conductive
materials, such as metal studs and
drywall, that are poor insulators. The result
is unwanted heat loss or gain or conditions
where condensation can occur.
141
GLOSSARY
Thermal bypass: Movement of heat around
or through insulation that occurs when
gaps exist between the air barrier and
insulation or where air barriers are missing.
Thermal conductivity: Quantity of heat
transferred through a material due to the
difference in temperature on both sides of
the material.
Thermal isolation: Space that is heated
and/or cooled by a system separate
from the other conditioned spaces of the
building or controlled as a separate zone.
U-factor: The measure of how much heat
a building element conducts or thermally
transmits. The lower the U-factor, the
more energy efcient the building element.
Window and door performance labels
include U-factors to help compare
different fenestration products.
Unconditioned space: Interior space
outside the building thermal envelope
that is neither heated or cooled.
Vapor barrier: Material that prohibits or
severely limits the entry of water vapor
into and out of building assemblies.
Because a vapor barrier traps moisture,
use is limited to at-grade applications
over dirt and below slabs. Interior vinyl
coverings can act as vapor barriers and
should be avoided, particularly in air
conditioned structures.
Vapor diffusion (transmittance): The
process by which moisture moves
from areas of higher vapor pressure or
temperature to areas of lower vapor
pressure or temperature.
Vapor retarder: Material used to control
the entry of water vapor into and out
of building assemblies through the
mechanism of vapor diffusion.
Vent: A device that is part of a heating
or ventilation appliance or system that
conducts fresh air into, or waste air or
combustion gases out of, the appliance or
interior space. Examples include ue vents
and fresh air vents.
Vent chute: Elements placed between low
sides of roof rafters in buildings, typically
with vented attics, to permit air entering
soft vents to move freely above the
insulation, through the attic, and exit at
ridge vent or other roof-mounted vents.
May also protect insulation at low side of
roof rafters from displacement due to
wind exposure.
Vent damper: In a heating system, device
that causes a vent to close when the
heating unit is not ring in order to trap
heat rather than allow its updraft and
escape through the vent system.
Vent, direct: Component of a combustion
appliance installation that draws
combustion supply air from the outside
and vents combustion exhaust directly
to the outside. May be combined with
power vent exhausts.
Vent pipe: A duct, usually round, in which
combustion gases from an appliance are
vented to the outside.
142
GLOSSARY
Vent, power: Sealed exhaust ventilation
system for combustion appliances that
uses a fan to move combustion exhaust
outside the building. Depending on the
appliance, may be located at roof or walls.
Ventilation: The natural or mechanical
process of supplying or removing
conditioned or unconditioned air
to a space.
Ventilation, mechanical: Process of
supplying or removing air to or from an
indoor space by powered equipment such
as air handlers, motor-driven fans and
blowers. Typically excludes devices such
as wind-driven turbine ventilators and
mechanically operated windows.
Ventilation, natural: Ventilation of a
building without the use of fans or
mechanical systems.
Weatherization: Process of improving a
building to reduce its energy usage, may
include sealing gaps and penetrations
in a building to reduce air inltration and
exltration using sealants, caulks, foam,
and weather-stripping.
Weather-stripping: Material used to seal
gaps around perimeters and moving parts
of windows, exterior doors, and skylights.
May be metal, foam, felt, or vinyl.
Whole house fan: Mechanical device used
to pull air through an interior space and
exhaust it to a vented attic or directly
to the outside.
Wind bafe: Elements placed between
low sides of roof rafters in buildings, or
at other required locations, to protect
insulation from displacement due to wind
exposure.
Wind washing: Process of wind-driven air
moving through insulation. Wind washing
occurs most commonly in attic spaces
when air enters through soft vents and
directly encounters insulation. Insulation
at the eaves of vented attics should be
protected from wind washing using bafes
to allow unobstructed airow through the
soft vents without disturbing insulation.
Wind washing reduces the effective
R-value of insulation.
Window assembly: Includes the window
glazing, sash and frame. Windows are
U-factor rated for the whole assembly.
Zero energy building: See Net-zero
energy building.
Zone: A space or group of spaces within
a building with similar heating or cooling
requirements that permit desired indoor
air conditions to be maintained throughout
using a single control device.
143
INDEX
Index
A
Advanced framing
......................... 75
Air barrier
..................................... 127
Air conditioning
........................... 127
Air economizer
............................ 131
Air-impermeable insulation
.......... 127
Appliances
................................... 118
Attics
........................................92-95
Unvented
.................................... 95
Vented
........................................ 92
B
Barriers and Wraps
................... 33-40
Air, Water, and Vapor Control
..... 34
Barriers and Vapor Retarders
..... 35
Drainage Planes
......................... 38
Housewrap
................................. 39
Rainscreens
................................ 38
Selection of Barriers
and Vapor Retarders .......... 36
Weather-Resistive, Air,
and Radiant Barriers .......... 37
Basements
...............................56-63
Conditioned
...........................59-62
Dampproong
............................. 57
Rim Joists
................................... 63
Unconditioned
............................ 58
Batt insulation
.............................. 127
Blower door test
.......................... 128
Boiler
................................... 100, 128
C
Cellulose insulation
..................... 128
Central air conditioning system
... 128
Central heating system
................ 128
Chimney
...................................... 128
Cladding
...................................73-74
Climate Zones
............................... 15
Code
................................................ 2
Combustion air
............................ 129
Compact uorescent lamp (CFL)
129
Compressor
................................. 129
Condenser
................................... 129
Convective air ow
...................... 130
Cooling
........................................ 103
Crawl Spaces
...................64-66, 130
Unvented
.................................... 66
Vented
........................................ 65
D
Dampproong
................................ 57
Dense packed insulation
............. 130
Domestic Hot Water
.............113-116
Hot Water Heaters
.............113-116
Door assembly
............................ 130
Door installation
............................ 87
Door sweep
................................. 130
Double-pane or
double-glazed window
..... 130
Drainage
........................................ 11
Ducts
........................................... 130
Duct return
.................................. 131
Duct supply
................................. 131
Duct system
................................ 131
E
ECCCNYS (see Energy Code)
......... 2
Economizer
.................................. 131
Air
............................................. 131
Water
........................................ 131
Electrical
...............................119-125
Pool Heaters
............................. 125
Snow and Ice Melt Systems
..... 124
Energy Code
.................................... 2
Energy Recovery
Ventilation system (ERV)
... 132
ENERGY STAR
®
...................... 3, 132
EPA Indoor airPLUS
®
specications
................... 132
EPA WaterSense
®
........................ 132
144
INDEX
Exterior Lighting .......................... 123
Exterior Walls
............................ 71-82
Advanced Framing
..................... 75
Cladding
................................73-74
Insulated Concrete Forms (ICF).. 82
Mass Walls
.................................. 80
Metal Framing
............................. 72
Narrow Cavities
.......................... 79
Sheathing
.................................... 71
Structural Insulated
Panels (SIP)
........................ 81
Wood Framing
............................ 72
F
Fiberglass insulation
.................... 132
Flash and batt
.............................. 132
Floating slab
................................ 132
Floors
........................................89-91
Cantilevered
................................ 90
Level Changes
............................ 91
Separating Conditioned
and Unconditioned
Spaces
............................... 89
Flue
.............................................. 132
Foam Insulation
........................... 132
Foundations
..............................53-55
Drainage
..................................... 55
Types
.......................................... 54
FSK radiant barrier
...................... 133
Furnaces
...................................... 101
G
Geothermal heat pump
....... 102, 133
H
Heating
..............................................
Boilers ...................................... 100
Conditioned Spaces
................... 99
Duct Insulation
......................... 106
Duct Sealing
............................. 105
Furnaces ................................... 101
Heat Pumps
.............................. 102
Programmable Thermostats
..... 104
Heat pump
........................ 102, 133
Heat pump, air-to-air
................... 133
Heat pump, air-to-water
.............. 133
Heat pump, geothermal/
ground source
.................. 133
Heat pump, geothermal/water
source
.............................. 133
Heat recovery ventilator (HRV)
.... 133
HERS (Home Energy Rating
System)
............................ 134
High efciency lamps
.................. 134
Housewrap
.................................... 39
HVAC (Heating, Ventilation,
and Air-Conditioning)
....... 134
Hydronic system
.......................... 134
I
Incandescent
............................... 134
Insulated concrete
forms (ICFs)
................. 82,135
Insulated contact lighting
xture (IC)
......................... 135
Inspections
...................................... 5
Insulation
..................................20-32
Batts (Blankets)
.......................... 24
Blown (Dry)
................................. 28
Cellulose
..................................... 28
Comparing R-Values
.................. 22
Dense Pack
........................ 27, 135
Fiberglass
........................... 23, 136
Flash and Batt
............................ 25
Foam
.................................. 31, 136
Materials
..................................... 21
Mineral (Rock or Slag) Wool
....... 32
Rigid Board
......................... 30, 136
Sprayed (Damp)
.......................... 28
Spray (Open or Closed Cell)
... 31,136
145
INDEX
L
Lighting
................................. 119-123
Exterior
..................................... 123
Interior
...................................... 119
Interior Lamps
............................. 121
Interior Lighting Controls
............. 120
Low-E coating
............................. 137
Low voltage lighting
.................... 137
Lumen
.......................................... 137
M
Manuals D, J, S, T
....................... 137
Mass Walls
.................................... 80
Mechanical ventilation
................. 137
N
Natural Ventilation
............... 107, 142
NYSERDA
................................. I, II, 3
O
Occupancy sensor
...................... 137
P
Penetrations
.............................45-51
Bathtub and Shower
.................. 49
Chimney
..................................... 46
Dryer
........................................... 48
Exhaust Fan
................................ 48
Exterior Wall
............................... 45
Flue Shaft
................................... 48
Heating and Electrical
................ 50
Interior Bypass
........................... 51
Other Roof
.................................. 47
Plumbing
.................................... 49
Recessed Lighting
...................... 50
Performance Testing
....................... 5
Photovoltaic (PV)
......................... 138
Plantings
........................................ 12
Plumbing Fixtures
........................ 117
Pool Heaters
................................ 125
Programmable thermostat
.......... 138
R
Radiant barrier
............................. 138
Radon
.................................... 13, 138
Rainscreen
............................. 38, 138
Renewable energy source
........... 138
Rigid Board Insulation
........... 30, 136
Roofs
........................................95-97
R-value
........................................ 139
S
Safety
.............................................. 7
Sealants
.................................... 42-44
Sealant Chart
.............................. 42
Sheathing (exterior)
..................... 139
Siding (cladding)
.......................... 139
Siting and Orientation
................. 9-10
Building Orientation
.................... 10
Site Selection
............................... 9
Skylights
................................ 88, 139
Installation
.................................. 88
Slab-on-Grade
..........................67-69
Exterior Insulation
....................... 68
Interior Insulation
........................ 69
Solar power
................................. 140
Split system
................................. 140
Spray foam insulation
.................. 140
Storm door
.................................. 140
Storm window
............................. 140
Structural Insulated
Panels (SIPs)
.................... 140
Sunrooms
...................................... 98
146
INDEX
T
Tankless water heater
.................. 140
Thermal Envelope
..................... 16-19
Envelope Testing
........................ 18
Infrared Thermal Imaging
........... 19
Thermal Bridging
........................ 17
Thermal barrier
............................ 140
Thermal break (barrier)
................ 140
Thermostats
................................ 104
U
U-factor
....................................... 141
V
Vapor barrier
................................ 141
Vapor retarder
.............................. 141
Vent
.............................................141
Ventilation
.............................107-112
Mechanical
....................... 108, 142
Natural
.............................. 107, 142
W
Water Economizer
....................... 131
Weather-stripping
........................ 142
Windows
................................... 83-86
Window Frames
......................... 84
Window Installation
.................... 86
Window Labels
........................... 85
Z
Zero energy building
.................... 142
New York State Energy Research and Development Authority
nyserda.ny.gov | [email protected].gov
Albany
17 Columbia Circle
Albany, NY
12203-6399
(P) 1-866-NYSERDA
(F) 518-862-1091
Buffalo
726 Exchange Street
Suite 821
Buffalo, NY
14210-1484
(P) 716-842-1522
(F) 716-842-0156
New York City
1359 Broadway
19
th
Floor
New York, NY
10018-7842
(P) 212-971-5342
(F) 518-862-1091
West Valley Site
Management
Program
9030-B Route 219
West Valley, NY
14171-9500
(P) 716-942-9960
(F) 716-942-9961
EES-CI-EC-fieldguide-bk-1-V2 5/15
