Owens Corning

Outline | Three Key Areas of Focus
•
1 Air Sealing •
2 Insulating
– Why & how houses leak – Material choices
GHBA Custom Builder Council – Importance – Proper installation
Air Sealing & Insulating Residential Buildings – Measuring air leakage – How infrared
– Sealant choices
Sealant choices thermography can help
thermography can help
– Ventilation

•
3 Bonus Room Comfort
20 September 2011 – Why it is such a challenge
– How it can be addressed with
Dave Wolf, Ph.D.
Owens Corning, Science & Technology
effective air sealing & insulating
Confidential Information 2

Air Sealing
How leaky is a typical house?

 

AIR SEALING
Leaky enough to exchange all of its volume
with the outside every two hours.
Median air leakage of existing homes is 0.5 NACH.
3 Residential Energy, Krigger & Dorsi.
4

Air Sealing Air Sealing
Where do houses leak? | Attic Where do houses leak? | Walls

Light fixtures Chimneys Wall ceiling
Wall-ceiling intersections

Hatches Vents Bath fans Soffits/Chases
Drawing from “The Facts About Insulation And Air
Infiltration,” NAIMA Pub. No. BI 480.
Drawings from “Attic Bypasses,” Minnesota Department of
Commerce Energy Information Center.
5 6

1

Why do houses leak air? What are the benefits of reduced air leakage?
1 Experience dramatic savings on home heating and cooling
See immediate savings of up to one‐third on heating and cooling.

Enjoy a more comfortable home
More consistent room‐to‐room comfort with fewer drafts. Feel warmer in the
winter, cooler in the summer.
2 Help prevent moisture from entering walls
Reduce conditions that can lead to the growth of mold.

Diminish outside noise penetration
Up to 40% less outside noise from traffic and neighbors, as compared to traditional
spray foam systems.

3
Defend against insects and pests
Block gaps and holes to create a first line of defense against the critters and pests
that bug your family.

Improved indoor air quality
Help seal out allergens and pollutants to create a healthier indoor environment with
the inclusion of a mechanical air exchanger.

Drawing from Green Building Advisor website.
7 8

How do you measure air leakage? Sealant Choices
Pros Cons
• The “Blower Door” test. • Low cost • Poor flexibility (without
silicone) & compressibility
– Pressurizes/depressurizes Caulk • Requires clean surface
the house to measure • No hard‐to‐reach joints

leakage. • Low cost • Poor flexibility &
• Good expansion compressibility
– Blower is quickly inserted Can Foam • Requires clean surface
into the door of the house.
into the door of the house
– The amount of air leakage is • Excellent flexibility & • Moderate cost
commonly normalized to the Spray Applied compressibility
house volume – air changes Flexible Foam • Self‐cleaning spray
• Seals hard‐to‐reach joints
per hour at 50 Pascals of
• Excellent expansion • High cost
pressure (ACH50). Full Cavity • Seals hard‐to‐reach joints • Does not address all joints
• Insulates
Spray Foam

9 Confidential Information 10

Air Sealing
Ventilation
• Old (and accurate) adage …
build tight, ventilate right.
– Infiltration (uncontrolled)
– Ventilation (controlled)

• Types of ventilation
Types of ventilation
– Supply
– Exhaust (not recommended for Houston climate)
– Balanced with heat recovery
INSULATING
• The builder should consult with the HVAC
contractor on the selection and installation.

Confidential Information 11 12

2

Insulating Insulating
Material & Application Choices Fiber Glass
• Fiber Glass • Advantages
– Inexpensive
• Cellulose
– Easy to install
• Spray Polyurethane Foam – Excellent fire & moisture
resistance
• Foam Board
• Disadvantages
– Batts must be custom fit for
irregularly shaped cavities
and obstructions
– Does not air seal

Confidential Information 13 Confidential Information 14

Insulating Insulating
Cellulose Spray Polyurethane Foam (SPF)
• Advantages • Advantages
– Inexpensive – Easily handles irregularly shaped
– Easy to install cavities and obstructions
– Provides some air resistance when – Air seals the cavities
tightly packed
• Disadvantages
g
• Disadvantages – Expensive
– Absorbs water – Requires building evacuation
– Can settle in wall cavities during installation and for
– Requires chemical treatment to avoid 24 hours thereafter
fire hazard – Requires highly trained installers
– Does not air seal


Insulating
Foam Board
• Advantages
– Continuous thermal break
(not interrupted by the framing)
– Can function as the water barrier, if
properly detailed

• Disadvantages
– May require window/door jamb
extensions, depending on the thickness.
– Requires some form of shear bracing
when applied instead of OSB or
plywood.


3

Insulating
More Information
• 12‐page pictorial
document that includes
quality checklists, critical
details and more.

www.owenscorning.com


Insulating
How infrared thermography can help …

BONUS ROOM COMFORT


Bonus Room Comfort Bonus Room Comfort
What affects comfort? Relative Humidity The Silver Bullet …
Moist air that infiltrates in the
Air Temperature summer makes a person feel warmer.
Moist air that exfiltrates in the winter • Bad news … There isn’t one.
makes a person feel cooler.

• A bonus room is the most thermally challenging
place in the house
– Five‐sided exterior enclosure
Air Flow Radiant
Air infiltration gives
the sensation of Temperature
Air infiltration and/or
draftiness.
inadequate insulation
• The details of construction are really important.
effects the wall
surface temperature, • Thermal barrier • Windows
which, through • Air barrier • HVAC
radiation, affects • Lighting
Source: Krigger, J. & Dorsi, C., Residential Energy, Cost Savings and
Comfort for Existing Buildings, 4th ed., Saturn Resource Management, 2004.
thermal comfort.


4

Thermal Barrier Thermal Barrier | Walls
• Two important requirements for the proper • Insufficient
installation of insulation sheathing on
the knee wall
1. Minimize/eliminate air leakage through the insulation
by ensuring a 6‐sided cavity
• Think of a sweater … very warm with no wind blowing; not so
Think of a sweater …  very warm with no wind blowing; not so Air leakage paths
warm with the wind blowing.  The 6‐sided cavity is the
“windbreaker” over the “sweater”.

2. Ensure contact with the surface that you want to
insulate
• Think of a blanket …  very warm when in contact with the body;
not so warm when separated


Thermal Barrier | Walls Thermal Barrier | Walls
• Open stud cavities • Double walls

attic
space

Air
leakage
path

Air Double-depth cavity;
leakage unbacked insulation
paths


Thermal Barrier | Walls Thermal Barrier | Floor
• Unbacked walls • Contact with the sub‐floor is essential

Correct Wrong

His & Hers
closet

All arrows show air leakage
paths and areas of
unbacked insulation. Source: Krigger, J. & Dorsi, C., Residential Energy, Cost Savings and
Comfort for Existing Buildings, 4th ed., Saturn Resource Management, 2004.


5

Thermal Barrier | Floor Thermal Barrier | Ceiling
• Piping creates a • Continuous and aligned
challenge for achieving air baffles in cathedral
contact with the sub‐ ceilings keeps the
floor. warm/cold air from
p g
seeping into the
• Could the plumbing insulation.
contractor apply a rigid
insulation between the
pipes and sub‐floor (e.g.,
foam)?


Air Barrier | Walls Air Barrier | Floor
Bonus Room

• Same examples as with the thermal barrier …
Garage House

All drywall Floor temperature
penetrations is affected.
must be sealed.
Air leakage paths

Air
leakage
paths

Air
leakage
path

Double-depth cavity; All drywall
unbacked insulation
All arrows show air leakage terminations
paths and areas of
unbacked insulation. must be sealed.


Air Barrier | Ceiling Air Barrier | Ceiling
• Seal around recessed lights. • Seal around exhaust fans.

Source: Retrofit Techniques & Technologies: Air Sealing – A Guide for
Contractors to Share with Homeowners, U.S. Department of Energy, 2010


6

Air Barrier | Ceiling Air Barrier | Ceiling
• Seal around duct boots. • Seal the top plates.

Sealant

Without a seal, the air from
the duct boot entrains
unconditioned attic air at the
drywall interface.


Windows HVAC
• Minimize their use in bonus rooms • Things to consider
– Windows are a weak link in the wall’s thermal barrier. – Duct size
• Is it large enough for the length of run and higher thermal load
associated with a bonus room?
• Consider higher performance windows on south‐ – Duct kinks
g g
facing and west‐facing walls of bonus rooms • The attic space above a bonus room is often smaller than the rest
The attic space above a bonus room is often smaller than the rest
– Low‐e coatings for a cooling climate, like Houston. of the house, making duct kinks more likely.
– Duct sealing
• Prevents loss of conditioned air to the attic (supply) and gain of
unconditioned air from the attic (return).
– Returns
• Bathroom & closet doors are often closed for privacy, which makes
the presence of a return duct more important.


Bonus Room Comfort
Lighting MORE INFORMATION
• Bathrooms typically have the largest Books
Residential Energy, Krigger & Dorsi
concentration of artificial lighting of any
room in the house Websites
• Written
• www.greenbuildingadvisor.com
• Incandescent lighting will worsen a
Incandescent lighting will worsen a • www.buildingscience.com
g
• Video
comfort problem in summer months • www.homeenergypros.lbl.gov
• www.bestofbuildingscience.com

• Compact fluorescent lights (CFLs)
significantly reduce this thermal load
QUESTIONS?


7

Owens Corning

Recommandé

Recommandé

Contenu connexe

Similaire à Owens Corning

Similaire à Owens Corning (7)

Plus de Greater Houston Builders Association

Plus de Greater Houston Builders Association (10)

Dernier

Dernier (20)

Owens Corning