The general recommendation is to change the air filter in a house every 1 to 3 months. However, the exact frequency depends on various factors such as the type of filter, indoor air quality, presence of pets, and whether there are allergy sufferers in the home. Here are more specific guidelines:
- Every 30 days if the indoor air quality is poor or there are smokers, or if the home uses a wood-burning fireplace.
- Every 60 days if there are pets in the home.
- Every 20 to 45 days if there are multiple pets or occupants with allergies or respiratory conditions.
- For vacation or rarely used homes, filter changes can be every 9 to 12 months.
Regular inspection of the filter is also advised; if it looks dirty or clogged, it should be replaced regardless of the time interval. Changing the air filter regularly helps maintain HVAC efficiency, indoor air quality, and system longevity.