The air filter of your air conditioner is a crucial element. The filter is there to remove particles from the air, such as dirt, dander, dust and other debris, all of which can otherwise contaminate the air in your home. Air filters should be replaced every one to three months. If you’ve ever looked at the packaging of your air filter (and you should!), you most likely have noticed a MERV and/or MPR rating. What exactly do these ratings mean?
What Do MERV and MPR Stand For?
MERV and MPR are two different rating systems for HVAC air filters, and their ability to filter and capture particles and other airborne pollutants. The ratings are based measurements in micrometers, or microns. To illustrate how small a micron is, a piece of paper is 100 microns thick, while a human hair is 80. Pet dander is only 2 to 4 microns thick, and can float in the air for several hours.
MERV stands for Minimum Efficiency Reporting Value. This rating is regulated by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE). While it is an independent rating system, it is nationally regulated, and every air filter has a MERV rating.
MPR stands for Microparticle Performance Rating. This system was developed by 3M, and is only used on 3M and Filtrete air filters.
What’s the Difference?
The MERV rating ranges from 1 to 16. Most homes use filters with a rating between 8 and 13. The system is designed to measure the worst that a specific filter can perform, filtering particles ranging from 0.3 to 10 microns. The higher the rating, the smaller the particles that a given filter can remove from the air. For instance, for a rating of 13, a filter must remove approximately 90% of contaminants ranging from 3 to 10 microns, 85% of those ranging from 1 to 3 and 50% of those ranging from 0.3 to 1.
An MPR rating, on the other hand, only takes into account particles ranging from 0.3 to 1 microns in size. The higher the rating, the smaller the particles the filter can remove. This system does not consider particles larger than 1 micron.
So, how do the two ratings compare to one another? A MERV rating of 6 is approximately equivalent to an MPR rating of 300. A filter with these ratings have the ability to remove dust, lint and pollen. A MERV rating of 8 equates to an MPR rating of 600. This filter can remove the first three contaminants plus dust mites and mold spores. Finally, a MERV rating of 13 is similar to an MPR rating of 1500 to 1900. In addition to the previously mentioned contaminants, these filters can also remove pet dander, smoke, smog, bacteria and viruses.
Getting the right air filter for your air conditioner, and your home, is essential to the efficiency of your unit and the quality of the air you and your family breathe. If you have any questions about the best air filter for your needs, be sure to contact Brinson and Sons of Wilmington, North Carolina today.