Air-Filter Efficiency: Investigate Factors That Influence Savings

Air-Filter Efficiency: Investigate Factors That Influence SavingsUnderstand the Importance of Ratings When it Comes to Air Filters


There are two types of heating and air filter ratings. One is HEPA. This stands for High Efficiency Particulate Arresting. HEPA is a more strict government rating for an air filter and is not recommended for home heating or cooling use. The most common and less expensive equipment filters have MERV ratings. MERV is an acronym for Minimum Efficiency Reporting Value. True HEPA filters are in the highest ratings range of the MERV filters, 17 to 20. Air filters rated this high have to, by law, show that they are able to remove 99.97 percent of all in-home airborne contaminants. Their problem is that they restrict air movement.

MERV rating range

The range for MERV filters is normally 1 to 16. The lower range is rather porous and catches only large particles. The high range up to 16 is good to catch many contaminants but is more dense and restricts air flow. Restricting air “starves” your home of good circulation. Without easy and unrestricted air flow, your equipment must work harder to both deliver heating and cooling and, therefore, uses more energy, increasing operating costs.

Harmony between your air filter and equipment

Mid-range MERV-rated filters are generally the best option for homeowners. A filter rated in the 9 to 12 range on the MERV rating scale can give both good filtration for your equipment as well as good air circulation in your home. Air flow is necessary to circulate heating and cooling properly as well as move contaminants more easily through the system into the filter. Matching air filter to equipment will provide both good indoor air quality and maximum energy savings.

Different manufacturers recommend certain MERV ratings for best performance. If you’re not sure what rating is best for your system, consult your heating and air technician.

To make sure you have the correct filtration for your home and equipment, contact us at T.F. O’Brien Cooling and Heating. Our indoor air experts can guide you to the best filtration to maximize your efficiency and keep your indoor air clean. Call on us with your questions. We’re ready to help.

Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems).   For more information about air filters and other HVAC topics, download our free Home Comfort Resource guide.

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