MERV stands for Minimum Efficiency Reporting Value. This system is designed by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE). MERV ratings are derived from the ASHRAE 52.2-2012 test which groups the particles sizes into three categories. Small (.3-1.0 microns) Medium (1.0- 3.0 microns) and Large (3.0- 10 microns).

MERV ratings range from 1-16. The higher MERV rating does not always mean the better. Energy is the largest cost of operating a heating & air conditioning system. Having a higher MERV rated filter might contribute to a higher pressure drop depending on the filter selection. Which correlates to high energy cost of running your system. Our sales staff is CAFS certified and can help deciding on the right filter for you.

ASHRAE Standard 52.2-2012 test is done in a laboratory using a laboratory generated aerosol known as potassium chloride (KCI). It determines a filter’s efficiency in removing 12 different size fractions of dust using an optical particle counter. Smith Filter uses an independent third party testing laboratory for all products. This way of testing keeps us honest in the industry. Please ask our sales team for a copy of our test results if needed.

Here is the break down on typical filters in each MERV rating group:

MERV 1-8: Throwaway disposables- Fiberglass or synthetic panel filters. Smith products: Smith Economy Pleat, Smith Deluxe Pleat, Charcoal Pleated (odor removal), Fiberglass, Polyester, Self- Support Panels or Links, and Paint Arrestors.

Washable metal mesh- Galvanized, Aluminum, and Stainless. Smith products: Thrift-Aire, Lifetime, Heavy Duty, Bonded Aluminum, Perm-A-Steel, Steel Smith, 430 and 304 Stainless Steel, and Mist Eliminator, Foam, Perm-A-Foam, Hog Hair, and Poly Flo.

Electrostatic- Self charging woven polypropylene panel filter. Smith products: Electrostatic

MERV 9-14: Pocket Filters- Bag filters. Smith products: Smith Bag Filter MERV 9, 11, 13, and 14.

Disposables- High Temp Pleated.

Cell Style Filter- Rigid Cell and ASHRAE. Smith products: Smith Rigid Cell MERV 9, 11, 13, and 14 (Fiberglass & Synthetic), Smith ASHRAE MERV 11, 13, and 14 (Fiberglass & Synthetic).

MERV 15-16: HEPA type filters. Smith products: Smith HEPA.

Please use the link below to view a full description.

Download MERV Rating Chart