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08_14_13Air filters in your central cooling and heating equipment serve as a barrier to common pollutants such as pollen, pet dander, dust mites and tobacco smoke, which find their way in your home every day. Without proper filtration, these allergens can ruin your indoor air quality, and set your respiratory system into a tailspin.

Aren’t all air filters basically the same?

The answer is no. Fortunately, the HVAC industry has a standard rating system in place. All air filters come with a Minimum Efficiency Reporting Value, or MERV rating, that tells consumers how effective they will be at removing particles from the air. For residential purposes, ratings range from 1 to 16. For example, a standard 1-inch fiberglass filter with a rating of MERV 4 will remove less than 20 percent of particles down to 3.0 microns as they pass through your ductwork. This includes pollen, dust mites and carpet fibers. Upgrading to a pleated filter with a rating of MERV 8 will dramatically improve your indoor air quality by removing at least 70 percent of similar particles, in addition to mold spores.

What about HEPA filters?

High-efficiency particulate air (HEPA) filters use an advanced design to trap particles down to .3 microns with 99.9 percent effectiveness. They are primarily used in hospital or clinical settings. HEPA filters can be used in central HVAC systems in residential settings, but usually require professional modifications to existing equipment and ductwork, which can make them costly options for homeowners. Stand-aline HEPA air cleaners are also available for comprehensive air purification in the home.

HEPA-like air filters

Choosing an air filter with a MERV 7-13 can provide virtually the same level of filtration as a HEPA filter without the modifications required to install those types of filters. According to the federal EPA, filters rated above MERV 13 will not provide a significant increase in the reduction of indoor air pollutants but may impede airflow in your system, which is something to be avoided. Changing your air filters on a regular basis will do more to ensure that your indoor air remains clean.

At Crawford Services, we understand the importance of maintaining the air quality in your Dallas area home. Proper installation is the key to getting the most of any air filtration device, so call us today and let us put our experience to work for you.

Our goal is to help educate our customers in North Texas about energy and home comfort issues (specific to HVAC systems).

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