4 Reasons Why Your Filter Isn't Filtering the Air

Dust particles and other airborne contaminants in your home can make you less comfortable and aggravate allergies, asthma and other respiratory conditions. Your HVAC filter plays a big role in keeping your indoor air clean. If it’s not doing the job, here are four possible reasons why.

When a filter becomes too dirty, air will go around the filtration section and deposit dirt directly on system components, such as the fan or blower. Much of that stuff can get blown back into your home, reducing indoor air quality. Replace your filter now if it looks dirty and clogged like the one pictured above, then change it regularly according to manufacturer’s instructions.

Filters are designed so that air should flow in only one direction through the filter medium, and most filters have arrows printed on the side indicating the right direction. A filter facing the wrong way will not capture dust particles as well. That unwanted debris will end up on HVAC system components and floating in your home’s air. When installed correctly, the filter arrows should point toward the furnace.

That cheap one-inch filter may be cheap, but it’s not doing a whole lot to improve your indoor air quality. Filter performance is measured by Minimum Efficiency Reporting Value, or MERV. For many homes, a MERV value between 7 and 12 is adequate to remove most dust particles and other contaminants.

No filter, of course, means no filtration. For most units, a filter slot is located where the return air duct connects to the furnace. Some systems have the filter placed behind a return air vent, so check wall or ceiling vents. If you don’t have a filter, install one immediately. It’s also likely that your system needs to be cleaned and inspected, so schedule a tune-up with a qualified, SWEPCO-approved contractor.