Surprisingly, the air inside your home can be more polluted than the air outside. Fortunately, a high-quality HVAC filter can help.
People often talk about outdoor air quality and how it affects our health—but poor indoor air quality can be just as detrimental. Poor indoor air quality can cause or contribute to the development of infections, lung cancer and chronic lung diseases, according to the American Lung Association.
“Mold, dust mites, insect feces and other particles in the air can trigger allergies and asthma attacks,” says Janice Nolen, assistant vice president of the American Lung Association in Washington DC.
If you want to improve indoor air quality, keep sources of pollution out of the home by ensuring you have good ventilation, both into and out of the house, Nolen explains. “A lot of mold, bacteria and other pollutants need moisture to grow. So keeping humidity levels below 50% and fixing leaks can help reduce risks,” she says.
What’s Your MERV Rating?
Another way homeowners can maintain healthy indoor air quality is by making sure their HVAC system (heating, ventilation and air conditioning) has filters with the recommended MERV (minimum efficiency reporting value), and that they are clean and operating effectively.
The MERV rating was designed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) in the 1980s to rate how efficiently a filter captures particles of different sizes. Filters for residential use have a MERV rating that ranges from 1 (least efficient) to 16 (extremely efficient). Ratings higher than 16 are for commercial and hospital use; the fans on home furnaces aren’t powerful enough to move air through them.
Choosing the right filter depends on your home and your goals. There are four categories of MERV filters to choose from.
Common disposable spun-fiber filters generally have a MERV rating of 1 to 4 and won’t stop particles of less than 10 microns. They catch pollen and dust mites, but aren’t ideal for maintaining healthy indoor air quality.
MERV filters with a 5 to 8 rating collect particles as small as 3 microns, such as mold, making them a better choice for homes.
Filters with a MERV rating of 9 to 16 are a good choice for families with allergies or respirator problems, and for people who want the best dust control possible. They filter out lead dust and Legionella bacteria, which causes Legionnaires’ disease.
Filters with a MERV rating higher than 16 require an HVAC system with a stronger blower fan than most home furnaces have. These filters typically are used in hospitals and cleanroom manufacturing.
No matter which filters you choose, replace them frequently (every three months or so) before they become clogged with dust, so they can work as they should.
To learn more about indoor air quality from our Sears Home Services experts, you can schedule a free in-home consultation.