How to Locate Your System’s Air Filters

To support maximum heating/cooling efficiency and performance, HVAC system air filters need to be changed regularly. Installing a fresh filter at least every other month reduces operating costs, improves indoor air quality and keeps comfort optimum throughout the house. It’s a simple DIY procedure once you know how—as long as you know where the air filters are, too.

In most homes, a single primary filter is located at the system indoor air handler. This filter serves the return airflow before it passes through the furnace and the air conditioner coil. Also, in some houses that do not have individual return air vents in every room, an additional filter may be mounted behind the central air return grille.

Air Handler Filter

In an upflow air handler—the most common in residential HVAC systems—the large rectangular return air duct usually runs down the side of the air handler and makes a 90-degree turn into the bottom of the unit. Return air then flows upward through the furnace and A/C coil.

Near the point where the return duct connects to the bottom of the air handler, the filter is usually installed in a vertical slot in the duct. The slot may (or may not) have a spring-loaded access door. To change the filter simply slide out the old filter and slide in a new fresh filter.

Air filters have directional arrows printed on the edges. When installing the new filter make sure the arrows point in the direction of the return air flowing into the air handler.

Central Return Filter

Typically located in the wall or ceiling of a main hallway of the house, the large central return air grille is usually hinged along one edge and secured with a locking screw.

Release the screw, open the grille and pull out the dirty filter. Use a rag to wipe residual dust out of the filter frame and off the grille. Install the new filter, close the grille and turn the locking screw.

To schedule maintenance or have a pro change your HVAC air filters, contact the pros at Energy 1 Heating & Air Conditioning.

Our goal is to help educate our customers in Lorain, Ohio about energy and home comfort issues (specific to HVAC systems). For more information about other HVAC topics, download our free Home Comfort Guide or call us at 440-201-2959.