Air Filters and Some of the Many Things It Pays to Know About Them

You want to take care of your air-conditioning system and make it last well beyond its warranty, so you dutifully change the air filter regularly. But as you buy those replacements, have you ever stopped and wondered whether you were buying the right one–the filter that would do the best job of removing particulates while also allowing optimal airflow? If you have asked that question, a good place to find the answer is the air filter’s MERV rating.

Meet MERV

MERV is an acronym for minimum efficiency reporting value. The rating indicates how effectively a filter removes particulates from the air. A MERV 1 rating is least effective, because it can trap only very large particulates, and a MERV 16 is the most effective. (HEPA filters, which cannot be used with most residential HVAC systems, have higher ratings.) So the best filter is a MERV 16, right? Not quite. Remember, you’re changing the filter because air cannot flow freely when it’s dirty.

So what should you get? The answer depends on your unit. For most residential systems, a MERV 8 to 11 filter can do an effective job–removing pollen, mold spores, pet dander, smoke and other contaminants–while ensuring adequate airflow. These filters, however, cannot remove bacteria from the air.

The right size 

Air filters must also fit properly to ensure the best circulation. You can find the size on the filter you’re replacing, or if it’s bent or ill-fitting, refer to your HVAC owner’s manual. If all else fails, contact your HVAC-system contractor.

For more information on the care and maintenance of your heating and cooling system, contact Mathews CCAC Inc. We’ve been keeping Corpus Christi residents cool since 1979.

Our goal is to help educate our customers in Corpus Christi, Texas 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.

Image courtesy of Shutterstock