Today's homes are more tightly constructed than ever. This means less fresh air infiltrates the home from outside.

However, it also means dust, grease, pollen, mold spores and other airborne particles that already exist in a home can't get out and are re-circulated over and over again.

To remove these particles, which may cause unnecessary physical discomfort as well as damage furnishings, more and more homeowners are turning to high efficiency air filtration systems.