When it comes to air filters, it can be a confusing task if you haven't done it before. Pretty much every product will say they're the best, so it's important to do some research and understand the specifications. The acronym MERV stands for Minimum Efficiency Reporting Value and is an essential indicator of an air filter's ability to trap unwanted particles. A MERV rating of 13 is suitable for keeping the air fresh and clean in a home without damaging the air conditioning system during the process.
Air filters with a high MERV rating mean that they have better filtration capacity. These particles are invisible to our eyes because we can't identify particles smaller than 40 microns. For comparison, human hair has a diameter of around 50 microns. Sensitive lab equipment can detect them, and the worst score in the test determines the MERV, since this rating is intended to measure the “minimum efficiency” of the filter. A product must trap 95% or more of the particles in order to be considered a MERV 16 filter.
While these are suitable for places like hospitals, they are not recommended for home use. MERV 13 will prevent less than 75% of 0.3-1.0 micron particles from passing through, MERV 14 up to 84%, MERV 15 up to 94%, and MERV 16 can trap 95% or more of the smallest particles. It's important to monitor your air filter and change it periodically with the right MERV value for your home and family. Filters with higher MERV ratings should be changed more frequently (at least every three months) to avoid airflow restriction, which can cause the system to operate inefficiently or even damage it. In addition, a MERV 12 filter that is only 1 (one inch) thick is likely to be more restrictive than a 4 (four inch) thick MERV 12 filter. Filters in the MERV range of 5 to 8 can also trap particles between 3.0 and 10.0 microns in size, but are more efficient at doing so. The American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) uses particle size to classify MERV values.
So when you're thinking about what type of air filter to place in your home, remember that it's best not to exceed the MERV 13 rating.
