When it comes to air filtration, two of the most popular options are HEPA and MERV filters. But which one is better? To answer this question, it's important to understand the differences between the two. The MERV scale, developed by the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE), is a useful way to compare the performance of different filters. The scale ranges from 1 to 20, with higher ratings indicating more effective filtration of smaller particles.
HEPA filters are considered the best of the best when it comes to HVAC air filters. They can trap airborne contaminants as small as 0.3 microns in diameter, which is much smaller than the average strand of hair on the head (45 microns). HEPA filters are tested with DOP, mineral oil, and other materials that generate a monodisperse particle. MERV ratings measure the efficiency of air filters by measuring the size of particles that can pass through them.
MERV 11 and 13 rated air filters are beneficial for people with asthma and allergies, as well as households with pets. However, HEPA filters require costly system upgrades and additional fans to filter the air, making compatibility difficult. In addition, MERV rates a filter's ability to trap microscopic and macroscopic particles; FPR ratings only look at the filter's ability to capture or remove particles from 0.3 to 1 micron. If you were to use the HEPA test on a 95% ASHRAE air filter, they would be approximately 50% efficient on 0.3 micron particles once they are loaded with dust.
So which filter is better? While HEPA filters are more effective at trapping smaller particles, they require costly system upgrades and additional fans for compatibility. On the other hand, MERV rated air filters are more affordable and easier to install but may not be as effective at trapping smaller particles. If you want to add HEPA filtration to your home, you can use a portable HEPA air purifier to further clean the air. Ultimately, it's important to consider your specific needs when choosing an air filter for your home or business.