Are You Changing Furnace Filters Enough?

Changing furnace filters when you can no longer see light through it is the easiest rule of thumb to remember.

If you’re thinking that you only have to be changing furnace filters once a year, you may well be shortening the life of your furnace. Actually, you should check your filter monthly and often change it monthly, depending on the type of filter you use. To determine if it’s too dirty, remove the filter and hold it up to the light. If you can no longer clearly see light, change the filter (see photo above).

Many costly repairs can be avoided by simply changing furnace filters regularly. If you don’t change the filter, lack of airflow through the furnace will cause it to overheat and shut down. Similarly, a dirty filter can cause an air conditioner to shut down because the coils freeze up when airflow is inadequate. Both events stress the system.

Furnace air filters primary job is to protect the blower motor and the evaporator coil from dirt. Blower motors become less efficient and more susceptible for failure when they get dirty.  A dirty evaporator coil decreases the airflow through the coil and can cause the air conditioner to freeze up if the cold air is not circulated properly through the home.

The other key job of the furnace air filter is the reduce the indoor air pollutants circulating throughout the home. Furnace air filters are rated by the amount of particulate that they can trap. The rating is called the MERV rating. The higher the MERV rating, the more they trap.

A 1? fiberglass filter that can be bought at most home centers and hardware stores typically have a MERV rating around MERV 4. These are usually adequate to collect the large particles that can harm the blower motor and evaporator coil.

While the highest MERV rating is 20, most filters designed for residential use have a maximum rating of 16. These include electronic media air filters that can trap up to 99% of the airborne pollutants in a home including pollutants as small as virus’.

The lower the MERV rating, the more frequently you should be changing furnace filters.

The experts at Midwest Comfort Heating and Cooling can review your present furnace air filter situation and offer any recommendations that can improve the indoor air quality of your home.