How to Clean an AC Filter and Reduce Energy Costs

Why You Should Clean Your AC Filter

  • Dirty filters block airflow, making your AC work harder. This uses more electricity.
  • Clogged filters reduce your AC’s efficiency and capacity.
  • Particles like dust and dirt trapped in a filter can allow mold and bacteria to grow.
  • Cleaning filters makes your home’s air cleaner and healthier to breathe.
  • Replacing a dirty filter can lower your AC’s energy use by 5% to 15%.

How Often To Clean The AC Filter

  • Check filters every 1-3 months during heavy use seasons.
  • Replace filters every 3-6 months for normal use.
  • Clean filters at least once a year before peak AC season.
  • Some high efficiency filters may need replacing every 1-2 months.
  • If filter looks very dirty, go ahead and clean or replace it.

What You Need To Clean An AC Filter

  • The old filter you are replacing.
  • A new replacement filter specifically made for your unit.
  • A vacuum with hose and brush attachment.
  • Soap and water.
  • Clean cloths, sponges, brushes.

Step-By-Step Guide To Clean An AC Filter

Turn Off AC Unit

Turn your thermostat to the “off” position before beginning. This will prevent the fan from turning on unexpectedly.

Remove Old Filter

Locate your filter either in the return vent or main plenum. Slide it out carefully without tearing it.

Take Outside and Vacuum

Use a vacuum crevice tool to remove loose debris from the filter. Vacuum both sides.

Run Under Warm Water

Rinse filter under warm running water, holding it gently to avoid bending.

Apply Soap and Scrub

Put mild detergent on a wet sponge and scrub to lift stuck-on dirt and buildup.

Rinse Thoroughly

Rinse detergent off completely until water runs clear. Gently shake excess water off.

Air Dry the Filter

Allow filter to fully air dry for at least 24 hours before returning to the AC unit.

Install New Replacement Filter

Once dry, install a new, clean filter of the same size and type in your AC.

Turn AC Back On

Return thermostat to desired temperature. Make sure air flows properly from vents.

Tips For Maximizing Filter Cleaning

  • Vacuum filter outdoors to contain dust.
  • Use a mild dish soap and warm water only.
  • Scrub gently to avoid damaging the filter.
  • Always use replacement filters made for your specific AC unit.
  • Consider upgrading to a pleated or electrostatic filter.
  • Mark your calendar to remind you when to check and replace filters.

Why Cleaning Filters Reduces Energy Costs

  • Keeps air flowing freely through the AC system.
  • Lowers the load on the blower fan motor.
  • Allows cooled air to flow better through ducts.
  • Lets the AC compressor easily cool incoming air.
  • Prevents system freezing and tripping safety controls.

Regularly cleaning your air conditioner filter extends the life of your AC system. It also saves you money by allowing it to run more efficiently and avoiding costly repairs. Just this simple maintenance routine will pay for itself through lower energy bills!

Frequently Asked Questions About AC Filter Cleaning

How do I know if my AC filter needs cleaning?

Check your filter if you notice reduced air flow from vents, the AC running constantly, higher energy bills or unusual smells from vents. Visually inspect the filter to see if it looks clogged with dust and debris.

What size filter does my air conditioner use?

The filter size should be marked somewhere on the frame holding the filter. Common residential sizes are 16x20x1, 20x20x1, and 16x25x1. Measure the length, width and thickness to find a direct replacement.

Where is the filter located in a central air system?

The filter is usually found either in the return air vent or within the main blower plenum itself. It may slide in from the side or front. Consult your owner’s manual if unsure.

My filter is in bad shape. Do I need to replace my AC?

Not necessarily. Replacing a filter is much cheaper than a new AC! Just be sure to use a replacement filter of the same size and type as your original.

Should I use water or soap to clean my filter?

For light cleaning, you can simply rinse the filter with water. For deeper cleaning to remove stuck-on gunk, use mild dish soap and warm water. Avoid harsh cleaners.

How can I remember to change my filter regularly?

Mark the date on your calendar, set a reminder on your phone, or tie a ribbon on your unit as a visual reminder. Check the filter when you pay your monthly bills.


Cleaning or replacing your central air conditioning filter regularly is some of the easiest and most cost-effective maintenance you can perform. By keeping air flowing freely through your AC system, it will run more efficiently and allow you to enjoy cleaner, healthier air circulation. Just this simple step can save 5% or more on costly cooling bills during warm weather! Be sure to properly clean and dry filters before reinstalling them. Mark your calendar with reminders so you never forget this important task. Your AC unit and wallet will thank you.