How are air conditioning and heating filters rated?
Filter rating methods: MERV, FPR and MPR
The air filters used in heating and air conditioning systems are rated based upon their ability to trap airborne particles. There are several filter rating methods. The most widely used are MERV, FPR and MPR. Of the three, FPR and MPR are proprietary.
To meet our customer needs, we created premium MERV 13 filters. But, what does that mean? Is a higher MERV rating better? Worse?
In this article we’ll focus exclusively on MERV as it represents the standard that most consumers and professionals use.
What is the MERV rating for air filters?
MERV is an acronym for Minimum Efficiency Reporting Value. If MERV sounds familiar it’s because MERV is the most widely used filter rating.
The measurement scale was created in 1987 by the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) to rate how the effective performance of air filters.
Professionals and researchers often talk about MERV ratings in terms of the size particles they are able to capture. Since the airborne particles we’re talking about are so small, we’ll take a more straightforward approach.
The table below breaks up the MERV ratings for furnace and air conditioning filter scale into 5 groups. Beside each group we’ve included a few examples of the types of the airborne contaminants that filters with that rating can capture.
|1-4||Carpet fibers, dust mites, pollen, sanding dust||Residential|
|5-8||Fabric protector, mold spores, pet dander||Better residential and commercial|
|9-12||Humidifier dust, lead dust, legionella||Superior residential, commercial and laboratories|
|13-16||Bacteria, most smoke, most paint pigments||Healthier residential and commercial* and hospital|
|17-20||Carbon dust, smoke, virus||Manufacturing cleanroom|
There’s an asterisk beside ‘best residential and commercial’ in the MERV 13-16 row because that’s an application not covered by MERV. We added the best residential and commercial use as our 1″ MERV 13 filters are made for those looking for hospital-grade clean air filtration at home or in the workplace.
Is a higher MERV rating better?
Yes. Generally speaking, a higher MERV rating is better as it is capable of filtering out more airborne contaminants. But, it’s also important to realize that there are limitations to how high of a MERV rated filter some residential HVAC units can handle.
Only commercial and industrial HVAC systems run filters with a MERV rating higher than 13. And, some older residential systems that struggle to effectively circulate air through a home’s ducts might not be able to use a MERV 13 filter. If you have a question about the furnace or air conditioner at your home or office we recommend you ask an HVAC professional.
We hope you are as excited about MERV 13 filters as we are! And, regardless of the filter brand or rating you use, be sure to change them at the suggested interval for the best possible performance.