The air Leakage in your home is making your home dirty

T air leakage in your home is making your home dirty. For many years a house that could “breath” or leak air through the walls was important to allow for drying of the wall. Then we started adding insulation and mechanical air conditioning and heating to our homes. This limited air flow through a wall so it reduced drying potential. The air leaking through walls, crawl space, and attic brings with it dirt particles or dust.


Air leakage through a wall is not required for drying the wall system once we started using mechanical systems for heating and cooling. The cooling system will dehumidify and the air movement, if designed right, will dry the air in the home. The exact humidity level in your home can be monitored and controlled using your mechanical system. This will improve comfort as well and provide for a healthier and cleaner home.

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The “dirty” air is caused through poor installation or missing insulation as air moves through your thermal envelope. As air moves through the crawl space, attic, and walls into your home it picks up dust particles and brings them inside the home. It can also carry insects into the home as some travel on the breeze that comes into your conditioned space. If you find dust in your home, that dust is the dirt moving through our thermal envelope into your living space. It also represents money wasted on trying to keep your home comfortable.


Using spray foam insulation or caulk in key locations can stop this air movement. This strategy will improve the air quality inside your home and reduce the amount of “dirty” air infiltrating your thermal envelope. Of course, building science is not a simple formula. If you stop the air leakage you will reduce your energy used to heat and cool your home, however you will need to have systems to control humidity year round. These are systems you should have anyway instead of depending on a wall leaking uncontrollably. No question for me that air leakage in your home is making your home dirty – understanding building science will fix this and many other issues faced in modern construction.

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Caulking for Healthy Indoor Air Quality – Learning From a Local Network of Thought Leaders

Crossroads FarmIn a recent Facebook post, I included this statement:

Caulking is one of the best protections for Healthy Indoor Air Quality in a home.

Which led to this question:

How does caulking help with healthy indoor air-quality?

The answer came from Insulation and building science expert, Ken Wells of Elite Insulation.

Air infiltration can account for 30% or more of a home’s heating and cooling costs, and contribute to problems with moisture, noise, dust, and the entry of pollutants, insects, and rodents. Reducing infiltration can significantly cut annual heating and cooling costs, improve building durability, and create a healthier indoor environment. According to a 2005 National Institute of Science and Technology (NIST) study, an energy savings of up to 62% can be realized by undertaking specific air tightness measures. In addition to energy loss, air infiltration reduces occupant comfort, interferes with efficient operation of mechanical systems, reduces indoor air quality, and contributes to condensation and moisture damage in the building envelope system. Using tight construction methods is said to be like closing a hole in your wall the size of an open window.

According to the Air Barrier Association of America, a “typical 2,500 square foot home has more than a half mile of cracks and crevices.” Unsealed, about a third of the air leakage in a home occurs through the floors, walls, and ceilings.