Which filter should I use in my furnace

Furnace filter is one of the most important and easiest item to maintain or improve your indoor air quality. Replacing the filter regularly is also important for the furnace blower. A standard furnace filter replacement frequency is 3-4 months. This is one maintenance aspect you DO NOT WANT TO MISS for the sake of your family’s health because the air you breath is filtered through it.

Every household will have different internal and external factors and needs. The filters start at a couple of bucks for the most basic one and go in the range of 50-60 $ or more depending upon the filter quality and rating.

Here is a quick chart explaining the filter need and price range. There are 3 general ratings criteria – MERV, MPR and FPR. Higher the rating (number), more expensive and better filtering capacity it will have.

MERV: Minimum Efficiency Reporting Value

MPR: Microparticle Performance Rating (used by 3M/Filterate)

FPR: Filter Performance Rating (used by Home Depot)

Interestingly enough, a high value (HEPA) filter is not recommended for furnaces because it may put a heavy burden on the furnace blower. Please make sure that the size of the filter you are buying matches with the size your furnace requires.

Some examples of different rated filters are: Filtrete MPR 300; Nordic MERV 8; Filtrete MPR 1000; Nordic MERV 12; Filtrete MPR 1500

Here is easy to understand comparison between different ratings and what it means for you.

Please be sure to let me know if this information is helpful to make an informed decision next time you are in the market.