Understanding MERV Ratings: What Do They Mean and How to Choose the Right One

MERV stands for “Minimum Efficiency Reporting Value” and is a measure of how effectively a filter removes particles from the air passing through it. The higher the MERV rating, the more particles the filter captures. This rating is determined by the effectiveness of a filter in filtering particles of different sizes, specifically 12 particles of different sizes from 0.3 to 10 microns (µm) in diameter that were created in a laboratory environment. These 12 particles are divided into three different size ranges (E1, E2 and E3) and four subranges that exist within each range.

Filters with a MERV rating of 8 to 13 are usually high-end filters for domestic use or high-quality commercial filters. Pleated filters that are MERV 8 to 13, unlike fiberglass, can effectively filter small particles and decrease pressure drop. Filters with higher MERV ratings trap small particles more effectively than filters with lower MERV ratings. In general, filters with a MERV 16 rating or lower are considered HVAC system grade filters for residential, commercial, and general hospital use.

The higher MERV rating means that an air filter will capture the most dust, while the lower rating means that a filter will capture the least amount of dust. 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. The answer to this question will vary depending on your HVAC system, but overall, aiming for a MERV rating between 8 and 13 is ideal for a typical home. It's best to select a filter with the highest possible MERV rating for your specific HVAC system.

All air filters require regular cleaning and filter replacement to function properly. Follow the manufacturer's recommendations for maintenance and replacement.