Understanding the Different Levels of Filtration Provided by MERV Ratings for Air Filters

Air filters are essential for keeping the air in your home or office clean and free of pollutants. The Minimum Efficiency Reporting Value (MERV) rating is the industry standard for measuring how effective an air filter is at capturing dust, pollen, mold spores, and other contaminants. MERV indices range from 1 to 16, with higher ratings trapping small particles more effectively than lower ratings. The MERV rating system is the most commonly used system for determining the effectiveness of an air filter.

A MERV 8 filter is known to be effective at filtering out particles, but a higher MERV rating will provide even better filtration. It's important to note that using an air filter with a MERV rating higher than recommended by the boiler or air conditioner manufacturer can actually impair its performance. In general, MERV 8 filters can filter 90% of the particles suspended in the air, MERV 11 can remove around 95%, and MERV 13 can block approximately 98%. FPR stands for Filter Performance Rating and is a patented rating system used by Home Depot for their branded air filters.

MPR stands for Microparticle Performance Rating and is a patented rating system created by 3M for their air filters. Considering the threat posed by the spread of COVID-19 and other germs, replacing a building's air filter with a HEPA one is a much more effective measure than using a MERV 13 filter. This is because HEPA filters are designed to capture particles as small as 0.06 to 0.12 microns, which is much smaller than what a MERV 13 filter can capture. The only way to add a HEPA filter to an existing installation is through a separate or portable HEPA air filtration system with its own specific fan designed to increase the resistance of this type of filter. When it comes to choosing the right air filter for your home or office, it's best to comply with the furnace manufacturer's recommendations or consult an HVAC professional to determine exactly which MERV rating is best for your specific system.

With the right information and guidance, you can ensure that your air filter provides you with the best possible protection against pollutants.