How Often Should I Change My Air Filter?

If you Google "how often to change AC filter," you'll likely see advice stating "every 3 months." If you follow that rule in Lancaster or Palmdale, you are likely killing your HVAC system.

Our environment is unique. We deal with:

• High Winds: Blowing sand and dust into every crack of your home.
• Seasonal Allergens: Pollen from Joshua Trees and agricultural fields.
• Wildfire Smoke: Ash from fires in the Angeles National Forest often settles here.

The 1-Inch Filter Rule: Every 30 Days

If you have a standard 1-inch fiberglass or pleated filter (the kind you buy at Home Depot in a 3-pack), you need to check it every 30 days.

During peak summer (July-August) and windy season (April-May), it usually needs to be replaced monthly. A clogged filter restricts airflow, causing your coil to freeze and your compressor to overheat.

The Better Solution: 4-Inch Media Filters

If you are tired of monthly changes, consider upgrading to a 4-inch or 5-inch media cabinet. These thick, pleated filters have massive surface area. They trap smaller particles and only need to be changed every 6 to 12 months, even in our dusty climate.

Pet Owners Warning

If you have dogs or cats, their fur and dander will clog a standard filter twice as fast. In the Antelope Valley + Pets scenario, a monthly check is mandatory.

What MERV Rating Should I Use?

Don't just buy the highest MERV rating (like MERV 16). High-MERV filters restrict airflow so much that they can actually damage older systems. For most homes, MERV 8 to MERV 11 is the sweet spot: it catches dust and pollen without choking your system.