Air movement between your home and outside isn’t a bad thing. The EPA recommends that the air in your home be replaced by outside air every 3 hours – a rate of .35 ACH (Air Changes per Hour). As more air enters your home from outside, the more air you have to heat and cool. Unfortunately, most homes are not sealed up properly, and they have an air change rate of 10 per hour! That is 1/30th as effective as recommended by the EPA.
Improving Your Homes Air Circulation
Why is this important to you? You are having to heat 30 times as much air as is recommended! Not only do you have to heat more air, your home is getting all of the moisture during the summer and losing all its hot air in the winter. Essentially, the stack effect, which is the total effect of air buoyancy forces on your home, is causing your home to be less comfortable, more humid, and more expensive to heat.
How can you stop the stack effect? The best way to stop the stack effect is to seal off your home until you get the recommended ACH. As mentioned before, the home has many entry/exit points for air. Doors, windows, attics, crawl spaces, and even the cracks between your siding will cause your home to lose air.
While most people decide to upgrade their windows and doors to improve energy efficiency, this often has the least impact. Up to 40% of heat loss is through walls, up to 35% is through attics, up to 10% air loss is through floors, and up to 25% is through your windows and doors! Don’t mistake air loss with a need to replace windows; address the real problem – your walls and attic.
Many walls and attics are insulated, albeit under-insulated. Some people have older homes without insulation. In fact, in the United States, insulation was not required in homes until the 1970’s. This explains why up to 93% of homes in the U.S. are under-insulated. But how can air still escape through your walls and attic if you have insulation? Some stats say the average home has 2 miles worth of cracks on the outside. That’s like having a window open all year long! Fortunately, existing homes can now be retrofitted with improved home insulation with superior air sealing properties to stop the stack effect!