A Complete Guide to Changing Your AC Filter

One of the simplest yet most effective maintenance tasks you can do for your HVAC system is changing the air filter regularly. A clean filter improves air quality, boosts efficiency, and extends the life of your system. Here's everything you need to know.

Why Filter Changes Matter

Your AC filter traps dust, pollen, pet dander, and other particles. Over time, it becomes clogged and restricts airflow. This forces your system to work harder, increasing energy use by 5-15% and potentially causing costly breakdowns.

Step 1: Find Your Filter

Locate your return air vent or the filter slot in your HVAC system. Filters are typically found in one of three places: the return duct, the air handler unit, or wall/ceiling vents. Check your owner's manual if you're unsure.

Step 2: Note the Filter Size

Before removing the old filter, write down the size printed on the frame (e.g., "16x20x1"). You'll need this information to purchase the correct replacement. Never guess the size—using the wrong filter can reduce efficiency or damage your system.

Step 3: Remove the Old Filter

Turn off your HVAC system before changing the filter. Slide out the old filter carefully to avoid spreading trapped particles. Note which direction the airflow arrow points—this will help you install the new filter correctly.

Step 4: Install the New Filter

Slide in the new filter with the airflow arrow pointing toward the blower fan. Make sure it fits snugly with no gaps around the edges. A loose fit allows unfiltered air to bypass the filter entirely.

How Often to Change Your Filter

• Standard 1-inch filters: Every 1-3 months
• Higher quality 4-5 inch filters: Every 6-12 months
• If you have pets, allergies, or live in a dusty area, check more frequently.