About Furnace Filters

Tucked away in a closet or the basement, your furnace filter is an item that doesn't get much attention. It's easy to forget it's there. But learning about furnace filters and making sure that you maintain them can make a big difference in your home and possibly even with your health. Furnace filters need to be replaced several times a year. Read on to learn more about furnace filters and how they can help you and your home.

Significance

The average person breathes in 32,000 pints of air every day. These 32,000 pints of air contain over 1 billion dust particles, which can contain contaminants, pollution and allergens. Researchers have found that indoor air is generally two to five times more polluted than outdoor air. Furnace filters can significantly reduce the amount of pollution and dust particles inhaled by the members of your household.

Function

Furnace filters trap dust particles, dust mites, molds, allergens and pet dander and keep these contaminants from recirculating through the heating system. Beyond this, clean furnace filters help the furnace to run more efficiently and extend the life of the furnace. Replacing furnace filters frequently can also reduce your heating bill in the winter by helping the furnace to run more efficiently.

Types

Pleated furnace filters use a dense mesh to trap dust and allergens. This type of filter can be very cheap or very expensive depending on quality and MERV rating.
Disposable fiberglass filters are the least expensive type of furnace filter. These filters are effective enough to protect your furnace, but they're not effective enough to protect your lungs. Allergens and other small particles pass right through.
Electromagnetic filters are washable and therefore reusable, so you don't have to continually buy new filters. They attract dirt and dust, but they're not very effective against allergens.
HEPA filters are very good at blocking allergens, but they're also good at blocking airflow. You'll want to do some investigating about your furnace before you use a HEPA filter so you don't damage the furnace.

Considerations

Most furnace filters today have a MERV rating on their labels. MERV stands for Minimum Efficiency Reporting Value. The higher the MERV rating is, the more contaminants the filter will weed out of your air. Generally, filters with high MERV ratings are more expensive, but this isn't always the case. Be a careful consumer and read the labels.

Expert Insight

The American Lung Association recommends using a furnace filter with a MERV rating of at least 10. They also recommend that you change your furnace filter quarterly, the first day of each season. If any members of your household have allergies or other respiratory problems, consider replacing your filters more frequently than quarterly.