You may have heard about the stack effect and how it creates humidity and health problems in your home. But what is it?
The stack effect, also known as the chimney effect, is the movement of air in your home. And it all starts with the air in your crawl space or basement. As that air warms it's pulled up through your home and exits at the top through the chimney, gaps in the attic or loose windows. It's a continuous cycle.
While the stack effect seems harmless enough, it contributes to mold, humidity and dust mite problems within your home. Anything that's light enough to hitch a ride on the air - like mold spores and humidity - is carried through your home with the air movement.
So if you have mold or high humidity in your crawl space or basement, you'll also have these problems in the living areas of your home.
Do You Have Health Problems?
The stack effect could be to blame. Mold and dust mites are among the most common culprits of allergy and asthma problems. While mold is an obvious problem, there's a hidden health risk lurking in your home...dust mites.
Dust mites don't live in your crawl space. But they love areas that have a humidity level over 50% and are inhabited by people - like your living room couch or bed. While there are many ways to keep dust mites at bay, like removing all of the carpet in your home. One of the most effective ways to curb the invasion is to reduce indoor relative humidity to below 50%. Not only will this help keep dust mites out of your home it will also minimize mold.
How To Reduce Indoor Humidity
Since the stack effect carries humidity up from your crawl space, the best way to combat it is to seal or encapsulate your crawl space. This involves completely sealing your crawl space from the outside elements.
The first step is to install a 20-mil thick vapor barrier, like CleanSpace, over the floor and up the walls. This barrier prevents moisture from entering your crawl space through the floor or foundation cracks.
Next you'll want to cover the vents and doors with an airtight crawl space vent cover which prevents outside moisture from entering your crawl space and contributing to the humidity problem.
The final step step is to condition the air with a dehumidifier. A good crawl space dehumidifier will remove humidity, mold spores, be self draining and energy efficient.Resources:
Wikipedia. Stack Effect. Retrieved from http://en.wikipedia.org/wiki/Stack_effect
Wikipedia. House Dust Mite. Retrieved from http://en.wikipedia.org/wiki/House_dust_mite