When it comes to air filters, the Nominal Minimum Efficiency Value (MERV) rating is a measure of how effectively the filter prevents dust and other contaminants from passing through and reaching the air stream. MERV ratings range from 1 to 16, with higher indexes trapping small particles more effectively than lower ones. The best MERV rating for residential use is one that properly cleans the air in your home without decreasing airflow or overloading your HVAC equipment. Filters with a MERV rating of 14 to 20 are considered the highest, and include commercial, HEPA, and ULPA filters.
These are generally not necessary in most homes and businesses, but those with severe allergies should choose a filter with a higher MERV rating or also have an air purifier in their home with a True HEPA filter. Air filters with the highest MERV ratings are designed to trap the smallest particles and tend to be thicker. Filters with a MERV rating of 13 to 16 capture 90 to 95% of airborne particles from 3 to 10 microns in size, 90% of those from 1 to 3 microns and 70 to 90% of particles as small as 0.3 microns. In general, filters with a MERV rating of 16 or lower are suitable for air conditioning systems for residential, commercial and general hospital use.One of the best ways to determine which MERV classification you should use is to compare the options side by side. This will help you find the best filter for your needs without overloading your HVAC system.
It's important to remember that using an air filter with a MERV rating higher than that recommended by the boiler or air conditioner manufacturer can affect its performance.
