Most homes lose between 40% and 60% of their conditioned air due to leakage every hour. This level of leakage can account for 40% of your heating and cooling costs. Additionally, air leaks make a home feel drafty.
What is it?
Air leakage can be reduced using a variety of tools such as expanding foam, caulking, airtight can light kits, weatherstripping . Most homes leakage can be reduced between 15% and 50% using these methods.
The Stack Effect
The stack effect occurs in all homes. Simply stated, hot air rises, and escapes through the attic. As this air escapes, your home pulls in more cold air through the foundation and lower extremities in order to maintain the balance of pressure pre-existing in your home.
Many drafts that you feel are the direct result of the stack effect. Good air-sealing and a continuous air barrier between the attic and the home’s conditioned (living) space are important, not only to save energy and reduce fuel bills, but also to prevent moisture problems in the attic.
Sealing the foundation will further slow the stack effect. Sealing the sides (such as doors, windows, walls, outlets, etc.) will reduce more localized drafts.
- 1.0 & Higher- Sever air leakage
- .75 to .99- Extremely leaky
- .50 to .74- Very leaky
- .35 to .49 Fairly leaky
- .20 to .34 Fairly airtight (goal for most homes)
- .10 to .19 Very airtight (Mechanical ventilation needed)