Definition
An air filter is the replaceable panel, pleated or fiberglass, that sits in a return grille or a filter slot at the furnace or air handler and catches dust, lint, pollen, and other particles before they reach the blower and coil. It protects the equipment first; its MERV rating describes how well it captures smaller particles.
Also called: Furnace filter, HVAC filter
Why it matters to you.
Central Kentucky's spring and fall pollen, cottonwood fluff and agricultural dust load filters quickly, and the system runs through both a cooling and a heating season. A clogged filter restricts airflow, which can freeze the evaporator coil in summer or trip a furnace's limit switch in winter.
Practical guidance.
With the system off, check the filter regularly and replace it when it looks gray or loaded, matching the size printed on the frame and pointing the airflow arrow toward the equipment. Ask a technician to confirm how many filters you have and what rating your blower can handle.
About this definition
Written by the Feistritzer Heating & Air Conditioning team — family owned and operated in Danville since 1976, Kentucky HVAC license M02584. Definitions inform; a whole-system diagnosis in your home decides.