How to Find My Air Filter

Locating My Air Filter

Just about all HVAC systems have an air filter that traps and holds dirt, dust, pollen, and other fine particles, and these filters should be changed on a regular basis to ensure that heating and cooling systems continue to operate efficiently and air quality in the home is maintained. While replacing an HVAC air filter is usually a fairly straightforward job, finding it is not always easy.

Protecting the HVAC Unit

The primary job of the air filter is to keep dirt and debris from entering and damaging the HVAC unit. This means that they are often placed in close proximity to the units they protect. Air filters can usually be found either in the duct that returns air to the main unit or next to a large metal box known as an air handler. However, there are many types of HVAC systems in use, which means finding the return duct or air handler may involve some searching around. The most common places to find HVAC air filters include:

• A slot on the duct that attaches to the air handler. Depending on the type of system you have, the return duct could attach to the top, bottom or side of the air handler.
• Behind ceiling or wall vents. If you find an air filter here, check the vents in every room as they each may need a replacement filter.
• Inside floor registers. This is common when air ducts run in crawlspaces or basements.

Air Filter Factors to Consider

Air handlers are often placed in closets. Some HVAC systems have separate heating and cooling filters, so check both the air handler and the return duct. Air filters have an airflow arrow on them. The filter should be installed with this arrow pointing toward the unit. Use HEPA-style filters if possible. Air filters should be changed more frequently if you have pets or members of your household who suffer from allergies. Before installing a new air filter, clean any dirt or dust off the grill that will be holding it in place.