It’s Time to Push for Greater Use of Higher MERV-Rated Air Filters
Technological advances over the last 30 years have increased the amount of sub-micron particles in the air we breathe. Manufacturing processes, material off-gassing and emissions are all adding to the airborne particulate matter that human bodies are not designed to filter. These particles can enter our bloodstreams through our lungs and cause a range of health problems.
Indoor air pollution has become an industry focal point, not just to the human processes that have created more sub-micron particulate matter, but also to the fact that humans now spend upwards of 90% of their lives indoors. Indoor air isn’t as quickly diluted as outdoor air, and furthermore, indoor air can constantly be “polluted” by the off-gassing of furniture, countertops, flooring and other materials inside the structure.
The advances in indoor air filtration are trying valiantly to keep up with the rise in indoor air pollution, but we need to emphasize the importance of equipping homes with more advanced air filtration systems. Until the 90s, residential HVAC air filters were designed primarily to protect the life of the machine, rather than the occupants. With advances in allergy science and the aforementioned increase in sub-micron airborne particles and the time spent inside, indoor air filtration has made a dramatic shift toward protecting human health.
But there is still a gap that needs to be closed. The majority of filters sold for residential air filtration capture less than 65% of particles in the .3 to 1 micron range, which represents most of this new category of manmade contaminants. In order to capture 95% of these particles, consumers need to use high efficiency filters. Two problems exist with this recommendation.
- The residential air filter market has edged away from MERV ratings (the official rating of ASHRAE), in favor of proprietary ratings like FPR (Home Depot) and MPR (3M). MERV is the only rating that will tell you what percentage of the .3-1 micron particles it can remove. So if you show up at Home Depot looking for a MERV rated filter, you will be hard-pressed to find one. They now sell almost exclusively FPR rated filters with values ranging from 1 to 10, which don’t adequately correlate to MERV values. Even the “best” FPR rated filter is said to equal a MERV 13 filter, which can filter at most 65% of the sub-micron contaminants.
- MERV filters above the 13 level are not widely available because residential HVAC systems that can accommodate a MERV 14, 15 or 16 filter are exceedingly expensive and not mainstream. Consumers who want that level of filtration will find themselves working with a specialty HVAC company and ordering filters from specialty providers, rather than using the local HVAC heavyweight and big box retailer down the street.
Now that we spend so much of our lives indoors and co-exist with much greater amounts of sub-micron particles our bodies are not designed to filter, we need to encourage greater use of advanced air cleaning technologies that protect human health and comfort.