Even More Reasons Why Venting Your Crawl Space is a Bad Idea

Ever heard of the term stack effect?  It refers to the idea that as warm air rises into a home, it leaks out of the upper levels.  New air must enter to replace the air that escaped, which creates suction at the lower levels to draw air in.  In most homes, about half of the air escapes each hour out of the upper levels.  In older leaky homes, the exchange rate can be as high as two air exchanges per hour. 

So what does this have to do with venting your crawl space?  Well, the air that you breathe and live in upstairs originates from your cold, nasty crawl space.  This bottom-to-top airflow throughout the home means that whatever is in your crawl space air is in your home and is affecting you.  If there is high humidity, mold, or a damp odor in your crawl space, then it’s in the rest of your home, too. 

By having an open vent in your crawl space, you are creating the perfect environment for mold growth, odors, and uninvited creates.  Not to mention to high heating and cooling bills.  If you have an open vent during the frigid winter months, that cold air is circulating your home and making your floors even colder.  During the hot summertime, the high humidity levels are entering into your crawl space, creating condensation and mold.

The stack effect is what causes crawl space vents to suck air in rather than circulate air out, proving, once again, that it is never a good idea to vent your crawl space.