What Dr. Energy Saver Says About Air Leakage:
"By having your home professionally sealed, you can reduce your heating and cooling costs by 20% or more."
Air Seal Your Home for Energy Savings
"Who left that window open?
It's freezing in here!"

Not air sealing a home is like
leaving a window open.
Here’s a wake-up call: Many homes have the equivalent of an open window in terms of air leakage, even though all their windows are completely closed. Heat escapes through dozens of small holes, cracks and gaps spread throughout the house, from basement to attic. The combined area of these gaps can easily equal the area of a fully open window.
- Read more about where air leaks come from.
- Read more about finding the leaks with a blower door test.
- I've read enough, I want to Schedule my Home Energy Checkup!
Anecdote
Mr. and Mrs. Draft were having a spirited discussion (what their children more accurately called an argument) about the comfort level in their house during cold weather. “I don’t know what you’re talking about,” Mr. Draft observed, speaking into his cell phone from an upstairs hallway. “It’s toasty warm up here. I can’t feel any cold drafts leaking into the house.”
As warm air rises and leaks out at
the upper levels... the house sucks
new unconditioned (cold, hot,
damp) air in at the lower levels.
“I don’t understand how one part of the house could be so comfortable while another part is cold,” Mr. Draft said. “What can we do about this?”
The Stack Effect:
Air Leaking Out Causes Air to Leak In
Convection causes the warmest air in your house to rise. Since it’s lighter than surrounding air, it wants to keep rising, which is why the greatest amount of air leakage is into the attic, through dozens and dozens of cracks and openings (I’ll get to the origins of these openings in a minute). With air leaking out the top of the house, an equal amount of air is going to come in through openings lower down. Interior air leaks out the top, causing exterior air to enter at the bottom. This is called the stack effect, and it’s based on the fact that nature abhors a vacuum.
Dirt stains on fiberglass attic insulation
are a sign of air leakage.

