How Often to Change a Furnace Filter
Check your furnace filter once a month. ENERGY STAR advises inspecting, cleaning or changing the air filter in a furnace, central air conditioner or heat pump once a month. For when to replace it, the EPA says to follow the filter maker's recommendations.
1Month between filter checks (ENERGY STAR)
13+MERV rating EPA suggests when upgrading, if your system can take it
1Year between professional check-ups, heating system in the fall
How to tell when to change it
- Look at it every month. That's ENERGY STAR's interval for checking furnace, AC and heat pump filters.
- Follow the filter's label. EPA says all filters need periodic replacement and to follow the manufacturer's maintenance and replacement recommendations.
- Book an annual check-up. ENERGY STAR recommends a pre-season check of the heating system in the fall and the cooling system in the spring.
Which filter: MERV ratings
MERV (Minimum Efficiency Reporting Value) rates how well a filter captures particles, on a scale of 1 to 16. When upgrading, EPA suggests a filter rated at least MERV 13, or as high as your system's fan and filter slot can handle. HEPA filters are rated on a different system.
Sources
- ENERGY STAR (EPA and DOE), Maintenance Checklist
- US Environmental Protection Agency, What is a MERV rating?
Cite: Home Stats Data, "How Often to Change a Furnace Filter," https://homestatsdata.com/hvac/how-often-to-change-furnace-filter/