How To Tell Your Filter’s Efficiency Without A MERV Rating
When it’s time to buy a new air filter for your furnace or air conditioner, the best way to determine the efficiency of the new filter is by checking its MERV (Minimum Efficiency Reporting Value). The higher the MERV rating falls on the 1-16 scale, the more efficiently the filter will work. This rating system was developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) and is the industry standard for air filter ratings. The federal EPA suggests that most homes use a MERV 7 to 12 air filter for the best results.
What happens, however, when you go to a big-box retailer and can’t find the MERV number on the air filter packaging? Since MERV isn’t mandated by the government, individual manufacturers can use their own rating systems. 3M uses an MPR (Microparticle Performance Rating) and Honeywell and Rheem use FPR (Filter Performance Rating). Each of these systems uses its own scale. The problem is that if you don’t realize that the filter is using a different rating system, you may not be buying the correct filter for your system, or worse, you could be spending too much money on a filter that you don’t really need.
Since you will not find a MERV conversion chart at most stores, here’s a short comparison that will help you determine which filter ratings are right for you. MERV 8 filters equate to an MPR of 600 and an FPR of 5. MERV 10 is equivalent to an MPR of 1000 and FPR of 6. MERV 11 is equal to FPR of 7. MERV 12 is the same as MPR of 1900 and FPR of 8 or 9. MERV 13 filters are equal to an FPR rating of 10. The biggest issue with multiple rating systems, especially those created by the manufacturer, is that they are not independently verified.
If you have questions, or need more expert advice on choosing an air filter, please contact us at Sobieski Services. Our goal is to help educate our customers in Delaware, Pennsylvania, Maryland and New Jersey about energy and home comfort issues (specific to HVAC & plumbing systems).
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