You're Always Breathing Basement Air

Everyone knows that warm air rises, which is why the basement is always colder than the upper levels of your home.  However, the warm air that rises also leaks out of the upper levels, and the air that escaped has to be replaced somehow.  New air is constantly being sucked in through your basement or crawl space to replace the air that was lost.  With low air pressure on the lower levels, the home sucks on the ground, then blows air out of the upper levels due to a higher air pressure.  This is known as the “stack effect.”

In the average home, about half of the air escapes each hour out of the upper levels.  In older homes that have more leaks, the air exchange rate can be as high as full air exchange per hour.  Why is it so important to be aware of this?  Well, studies have shown that 50% of the air you breathe on the first floor in your home is air that came from the basement.  Therefore, whatever is in the air in your basement may be affecting you more than you think.

Don’t believe this is true in your home?  There’s a test you can do to prove it.  In the winter, open a window in your basement and feel the cold air blasting in at you.  Then, go upstairs (to the second floor if you have one) and crack the window open an inch or so.  You won’t feel any cold air blowing in on the upper level because warm air is blowing out.  This is because the air pressure upstairs is higher than it is downstairs.

Many people think it doesn’t matter if their basement is leaky or moldy because they never spend time down there anyway.  However, if there is high humidity downstairs, then there is even higher humidity upstairs than there would be otherwise.  If there is mold in the basement, there are mold spores in the air that you are breathing upstairs.  This is also true with damp odors that may be lingering in your basement or crawl space.  Also, studies have shown that prolonged exposure to mold can actually cause asthma, as well as irritate people with existing asthma and mold allergies.

Since there’s no way to prevent the stack effect from occurring, sealing off your basement as well as getting rid of any mold or odors is the best way to ensure that your family will be breathing healthy air in your home.