The Minimum Efficiency Report Value (MERV) rating for an air filter is a system used to measure how effectively the filter prevents dust and other contaminants from passing through it into the air stream. Filters with higher MERV ratings are able to trap smaller particles more efficiently than those with lower ratings. An official website of the United States Government, gov, belongs to an official government organization in the United States. The Minimum Efficiency Report, or MERV, values report a filter's ability to capture particles between 0.3 and 10 microns (µm).
All air filters require regular cleaning and filter replacement to function properly, so it is important to follow the manufacturer's recommendations for maintenance and replacement. Have you ever looked closely at your HVAC filters when replacing them? If so, you'll have noticed that each filter has a MERV rating, and this number has important implications. Filters with high MERV ratings can remove more harmful pollutants from your home, but they can actually reduce the quality of the air you breathe if you select a filter with a MERV rating that is too high for your HVAC system. MERV 11-13 air filters are a kind of midpoint between the cheapest and the most expensive. A MERV 14 or higher air cleaner can create more resistance in the airflow than a residential HVAC system is designed to withstand. The MERV rating of filters tells you, on a scale of 1 to 16, how effectively the filter traps small particles you don't want to circulate in your home, such as dust, pollen, mold, and other irritants.
Exceptionally powerful HVAC fans are needed to effectively push air through the filters at the upper end of the MERV rating scale. If someone in your household suffers from allergies or asthma, you should consider buying a higher MERV air filter. In residential HVAC systems, filters in the 1 to 4 range are the most common, but it's not uncommon for homeowners to use filters with MERV ratings up to 8 on typical home systems. Therefore, if you are looking for a high-quality oven filter that is not too expensive, a MERV 8-10 filter is worth considering. Oven and air filters above MERV 13 are typically found in a hospital environment, where air sanitation is of the utmost importance. Filters with higher MERV ratings generally have a denser filter material, which means more force is required to push air through the filter.
Therefore, while higher MERV ratings are more efficient, the recommended MERV ratings for residential filters are between MERV 7 and MERV 13. Basically, the higher the MERV rating, the greater the air filtration capabilities of a particular filter.