MERV: How To Navigate Efficiency Ratings To Improve HVAC Performance, Indoor Air Quality
When choosing a replacement air filter for your heating and cooling system, there is one essential thing you need to check: MERV (minimum efficiency reporting value). MERV measures overall air filter efficiency, with rating numbers from 1 to 16. The higher the MERV number, the more airborne matter the filter will trap.
Filters in the MERV 1-4 range clear less than 20 percent of all airborne particles on every pass, and they rarely catch anything under 10 microns in size. They are designed to catch pollen, dust mites, fibers and fine dust.
Filters in the MERV 5-8 range catch particles as small as 3 microns wide. The biggest upgrade here is the ability to catch mold spores. Efficiency here is slightly better as well. Filters at the higher end of this category will trap up to 35 percent of all airborne particles in a single pass.
Filters in the MERV 9-12 range will catch particles as small as a single micron in size. This will filter out auto emissions and lead dust, among other smaller dust particles. Efficiency ratings climb up to near 75 percent on a single pass with these filters. They are used in hospital labs, commercial buildings and residential homes.
Filters in the MERV 13-16 range will remove particles down to 0.3 microns in size. These will catch nearly all bacteria and cigarette smoke. This is hospital operating room quality,with an efficiency of up to 95 percent on every pass.
For expert advice on all home-comfort issues, please feel free to contact us at Symbiont Service Corp. We’ve been serving the Florida Suncoast since the early 1980s.
Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems). For more information about MERV and other HVAC topics, download our free Home Comfort Resource guide.