Furnace Filters are rated in “MERV”…ever wonder what exactly a “MERV RATING” is?

What are MERV Ratings?

MERV (Minimum Efficiency Reporting Value) is the industry-standard ratings system used to measure the effectiveness of air conditioner filters. Ratings for residential and commercial AC filters typically fall between MERV 5 and MERV 12. Filters with higher MERV ratings remove more small particles from your air than lower-rated filters.

The MERV system was developed in 1987 by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE), the international trade group that represents HVAC professionals.

What MERV Rating is Right for Me?


  • BetterOn Time Air Filters Better quality level filters are rated MERV 8. Filters rated from MERV 5 to MERV 8 are categorized as Better Residential filters. Filters in this range pick up most of the dust, debris, mold and pet dander in your home or office. This is the minimum quality level that we recommend to our customers and do not sell filters rated below MERV 8.
  • Best – Our Best filters are rated MERV 11. Superior Residential filters are rated between MERV 9 and MERV 12, and will pick up a larger amount of dust and allergens. We highly recommend these filters for any customers who have asthma, allergies and any other respiratory condition.
  • Best for Pets – These filters are made with Activated Charcoal, which is proven to eliminate odors, especially chronic household ones let smells left by pets and tobacco smoke. Our Best for Pets filters are rated MERV 8.

Why Not Go Higher?

Filters with very high MERV ratings (MERV 13+) are designed for specialized commercial uses (hospitals, clean rooms, etc.). These filters restrict air flow so much that they use substantially more electricity and can damage your air conditioner or furnace unit.

What About FPR and MPR Ratings?

FPR and MPR are proprietary ratings systems developed by home improvement stores and filter manufacturers.  They are not directly relatable to MERV (an FPR 4 filter cannot be compared to a MERV 4 filter).  These ratings systems are not endorsed or backed by ASHRAE, and we do not recommend using filters not rated under the MERV system.

You can order the right filter for you right now on our online filter store!  SWENSONS FILTER STORE