Is HEPA Or MERV Better For Your Home?According to the U.S. EPA, poor indoor air quality is a major environmental hazard. It’s also one over which you have some control. The first line of defense against poor air quality in your Indianapolis area home is giving proper attention to the home’s air filtration system(s). This applies to both HVAC filters and any extra filtration you may have in place.

HEPA, MERV, FPR and other types of air filter rating systems may seem confusing but are meant to describe one thing: an air filter’s effectiveness at trapping certain sized airborne particles. The only universally accepted rating system is the one called MERV, which was developed in 1987 by the American Society of Heating, Refrigerating and Air Conditioning Engineers, or ASHRAE.

MERV, which stands for Minimum Efficiency Reporting Value, rates air filters on a scale from 1-20, with each larger number representing a greater efficiency at filtering progressively smaller particles from air being passed through it. Air filters with MERV ratings of between 1 and 12 are typically those used in residential furnace and A/C systems. Those with ratings between 13 and 17 are generally reserved for use in hospital surgeries and some laboratories, but can be used in a residential system with equipment modifications. MERV-rated filters between 17 and 20, which are commonly called HEPA filters, are used in pharmaceutical and electronics manufacturing “clean rooms.”

The HEPA designation, which stands for High Efficiency Particulate Absorption (or Arresting or Air, in some cases), is given only to filters that pass certain standards set out by the U.S. Department of Energy. To be considered a true HEPA filter, the filter must be able to remove no less than 99.97 percent of particles passed through it that are 0.3 microns or greater in size. Although this capability makes them invaluable in clean rooms, they’re not for use in ordinary home HVAC systems unless serious system modifications have been made to accommodate them. Otherwise, they’ll cause airflow drop that negatively affects air circulation and will damage equipment not specifically designed for their use. HEPA filters may be used, however, in dedicated air purification systems and vacuum cleaners used in your home.

For further information or advice regarding HEPA, MERV and general air filter maintenance, please contact us at Mowery Heating, Cooling and Plumbing. We proudly serve the Indianapolis metro area.

Our goal is to help educate our customers in Brownsburg, Indiana and surrounding areas about energy and home comfort issues (specific to HVAC systems). 

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