Changing your HVAC air filter is the single most important maintenance task you can do yourself. A clean filter improves air quality, protects your equipment, and maintains efficiency.
Why Filters Matter
Air filters capture dust, pollen, pet dander, and other particles before they enter your HVAC system. A dirty filter restricts airflow, forcing your system to work harder. This increases energy costs, reduces comfort, and can cause equipment damage.
How Often to Change Filters
Standard 1-inch filters: Every 1-3 months 4-inch pleated filters: Every 6-12 months High-efficiency filters: Follow manufacturer recommendations
Change more frequently if you have pets, allergies, or run the system constantly.
Step-by-Step Filter Change
1. Turn off the system. Switch the thermostat to OFF to prevent the system from running during filter change.
2. Locate the filter. Common locations include the return air grille, inside the furnace cabinet, or in a dedicated filter rack.
3. Note the size. Filter dimensions are printed on the frame (e.g., 16x20x1). Write this down or take a photo.
4. Remove the old filter. Slide out carefully to avoid releasing trapped dust.
5. Check the airflow direction. Filters have an arrow indicating proper airflow direction. The arrow should point toward the furnace/air handler.
6. Insert the new filter. Slide into place with the arrow pointing in the correct direction.
7. Turn the system back on. Switch the thermostat back to your normal setting.
Choosing the Right Filter
MERV rating indicates filtration efficiency. Higher numbers capture smaller particles.
- **MERV 8-11:** Good for most homes. Captures dust, pollen, mold spores.
- **MERV 12-13:** Better for allergies. Captures finer particles.
- **MERV 14+:** Hospital-grade. May restrict airflow in residential systems.
Higher MERV ratings restrict more airflow. Check your system specifications before upgrading.
Signs You Waited Too Long
- Visible dust on the filter
- Reduced airflow from vents
- Higher energy bills
- System running longer cycles
- Dust accumulation in the home
Set a recurring reminder to check your filter monthly.