MERV Ratings: Choosing the Right HVAC Filter

MERV Rating (Minimum Efficiency Reporting Value) is a standard developed by ASHRAE in 1987 to measure the overall effectiveness of air filters used in HVAC systems. MERV values report the minimum performance of a filter based on particle size and airstream velocity. The precision of the MERV scale allows for improvements in cost, health and HVAC system efficiency by allowing users to choose filtration based on application and specific contaminants.

Higher MERV ratings are assigned to filters capturing the greatest percentage of airborne particles and contaminants. HVAC filters with MERV ratings of 1 to 16 are capable of filtering particles ranging from 0.3 to 10 microns.  Higher MERV ratings of 17-20 are assigned to HEPA and ULPA filters capable of trapping particles smaller than 0.3 microns. 

MERV 1-4: Lower-quality residential filters with minimal filtering ability.  

MERV 5-8: A better choice for homeowners, commonly used in commercial settings.  Can stop particles as small as 3 microns (mold spores, dust mite debris, pet dander).

MERV 9-12: Capable of filtering particles of 1 to 3 microns such as Legionella, humidifier dust, lead dust.  Usually used in commercial and industrial applications. 

MERV 13-16: Effective for hospital and surgery settings.  A MERV 16 filter captures more than 95% of particles spanning the full test range including bacteria and tobacco smoke. 

MERV 17-20: Used in pharmaceutical and electronics manufacturing and in clean rooms, these filters are capable of filtering viruses, radon, carbon dust.  Impractical for typical HVAC systems.

About MSC - The Go To Guys

We are a service sub-specialist in the technical intricacies of HVAC, process cooling, and building automation systems in commercial, industrial, and institutional environments. MSC is recognized as the leading industry expert in solving elusive problems and attaining peak performance from clients’ mechanical equipment and overall systems.

Located in northern New Jersey, MSC is the only specialized contractor of our kind in the Northeast and Mid-Atlantic regions. We are MSCA STAR-qualified, NEBB-certified, fully-licensed in electrical, plumbing and HVAC, and our engineers and technicians are the most knowledgeable in our field.

Mechanical Service Corp.
41 South Jefferson Road
Whippany, NJ 07981
732-884-5000
http://www.mscnj.com