Informational Guide

How To Properly Clean AC Filters

AC filters can be difficult to clean. Learn how to replenish your unit no matter what the brand of air conditioner.

by Josh M

Air conditioner filters trap dirt in the air that circulates through your home. If a filter gets clogged, the air conditioner can’t send air into your house. It pushes itself to the limits to try and pump air into your home, which uses more electricity and can damage the unit.

Learning how to clean an air conditioner filter ensures you’ll always have clean air in your home. It also helps maintain your expensive HVAC unit. That’s why we’ve prepared this guide for your future reference the next time you clean your AC filter.

carrier air conditioner

Central air filters look like basic cardboard constructions but have intricate fibers inside. Spun fiberglass or pleated paper make up the interior, and they’re fine enough to capture particles like pollen, mold, lint, bacteria, and more.

Central air filters are different from what you’d use in a window unit. Those filters don’t have a sturdy frame, so you can wash the entire soft filter in the sink or replace it altogether.

Manufacturers make filters from different materials, so some are more expensive. Many last for a long time, while others are washable. You might need certain filters depending on any pets you own, as well as any allergies or medical conditions people in your house have.

Different Types Of Central AC Filters

There are different types of central AC filters you can choose for your HVAC unit. Besides having distinct materials inside, they have assorted levels of effectiveness. The Minimum Efficiency Reporting Value (MERV) of a filter tells you how well it will trap debris. The scale ranges from 1 to 16, with the higher numbers being more effective.

Disposable Fiberglass Air Filters

Fiberglass air filters have a MERV rating of four, so they’re best used if no one in your home has a respiratory condition. There’s a layer of adhesive to ensure the debris stays in place without blowing into your system. These filters are disposable, so you’ll want to replace them every month.

Washable “Electrostatic” Air Filters

As the name implies, the cotton and paper fibers in electrostatic filters create static that grabs dust from the air. Most have a MERV rating of four. Since you can wash and reuse the same filter, it’s better for your wallet and for the environment.

Pleated “Allergy” Air Filters

Pleated air filters have a large surface area, so they catch most of the particles in the air. Due to the pleats, you might find your unit has to work harder, which can decrease efficiency. These filters have a MERV rating between 5 and 13 and come as reusable or disposable.

Electronic Air Cleaners & Filters

Electronic air cleaners have prefilters that clean air before it enters your HVAC system. They use electrically charged filters that you can clean every few months. These add an extra layer of protection to your AC unit since they use filters with a MERV rating of 10 or higher.

HEPA Furnace Filters

High-efficiency particulate air (HEPA) filters are 99.9% effective at removing debris from the air. They have a MERV rating close to 16. If anyone in your home has allergies, you’ll want to invest in a HEPA filter. A contractor can fit the filter into your AC unit.

Furnitures in Living Room

Why Is A Clean Air Filter So Important

It’s important to have a clean air filter in your AC unit because it affects the air you breathe. Ineffective filters don’t have the capacity to trap more debris, so you’re more likely to inhale mold and bacteria.

A clogged filter also wears out your HVAC unit, which can decrease its ability to keep your air at the ideal temperature. Over time, leaving dirty filters in your unit will damage the mechanics, which can lead to expensive repairs.

How To Clean The Central Air Conditioner Filters (Step By Step Guide)

Regularly cleaning air conditioner filters should become part of your monthly maintenance routine. It’s not hard to clean central air conditioner filters, but there are different steps to take according to the type of filter you’re using.

Most air filters are behind the unit’s return vent, which could be close to the floor or ceiling. Large units have multiple return vents, so you’ll want to check each filter during the cleaning process.

You can use water to clean central air conditioner filters, so it’s recommended to wash the dirt away with a hose. Water damages other types of air conditioner filters, so you can only use the brush or vacuum on them.

Reusable Or Washable Filters

To clean your reusable filters, you’ll need some cleaning supplies:

  • Screwdriver
  • Brush
  • Vacuum with attachments
  • Garden hose
Step 1:

Turn off the entire HVAC system. If it’s still running when you remove the air filter, debris will enter your home.

Step 2:

Use the screwdriver to remove the vent cover.

Step 3:

Take out the filter and go outside so you can clean it without the debris getting in your home.

Step 4:

Use the brush to dislodge any particles that are stuck on the filter.

Step 5:

Turn on the vacuum to remove the loose dirt and dust.

Step 6:

Use the hose to get the filter wet on both sides. Keep running water through the filter until it seems to flow freely.

Step 7:

Let the filter air dry.

Step 8:

When the filter is completely dry, you can reinstall it.

Metal AC Filters

The process for metal AC filters is like other washable options, except you’ll use a mild detergent when you wash it.

Before you begin, gather all the necessary supplies:

  • Screwdriver
  • Vacuum with attachments
  • Garden hose
  • Dish soap or mild detergent
Step 1:

Turn off the entire HVAC system so debris doesn’t blow through your house.

Step 2:

Use the screwdriver to remove the vent cover.

Step 3:

Take out the filter and vacuum all the dust and dirt from it. Be thorough, or it might turn to mud when you wash it.

Step 4:

Check and see which side is dirtier and turn that side down. Start spraying water through the back of the filter, so it pushes the dirt out instead of getting it stuck inside the filter.

Step 5:

Once the filter is relatively clean, use the dish soap to wash both sides.

Step 6:

Rinse the filter until no soap remains on the surface. Water should flow through the filter without forming soap bubbles.

Step 7:

You can use paper towels to partially dry a metal filter, but you still want to let it air dry to prevent mold from forming in your system.

Step 8:

When the filter is completely dry, you can reinstall it.

How To Clean The Air Filters Of Popular AC Units

The type of air filter your unit uses depends on many factors. The size of your home, the medical concerns of the residents, and what your HVAC professional recommends impact the filter you buy.

  • Cleaning Carrier Central AC Filter
    Carrier uses fiberglass, pleated, and washable filters, so check to see what type you have. You should replace fiberglass filters, but you can wash the others following the steps above.
  • Cleaning Samsung Split AC Filter
    Samsung units have an auto-clean function you can run as needed, but you should still clean the filter every two weeks following the steps above. Samsung also advises that you clean the exterior of the HVAC unit to prevent corrosion.
  • Cleaning Hitachi Inverter AC Filter
    Hitachi advises users to clean their filters every three to six months. Depending on your model, you might have FrostWash, which cleans the interior of the unit after it runs for a certain number of hours.
  • Cleaning Gree Central AC Filter
    You can clean Gree’s filters with water, and they recommend you clean them regularly. For best results, you should call a professional to clean the condenser coils every so often.
  • Cleaning LG Dual Inverter AC Filter
    You should clean the filter of your LG unit every two weeks. Since it’s a different type of system than a central AC, LG has a detailed video showing you how to take care of your air conditioner.
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People Also Ask (FAQ)

How many air filters does a central AC have?

Most houses have two air filters, both in the intake vent and return. Multi-level homes or those with a lot of square footage may have more filters. You can check with your HVAC company or system manufacturer to ensure you maintain them all regularly.

How often should you clean your central AC filter?

It’s best to clean most central air filters each month. During seasons of heavy use, you might prefer to clean it twice a month, just to ensure your unit works efficiently. Check the filter every week or two and see how it looks. If you see a lot of dust, then go ahead and clean it.

What happens if your central AC filter is dirty?

Your air quality will decrease if your central AC filter is dirty. Clogged filters also push your AC unit to work harder, which can cause it to overheat or even malfunction. Your electricity bills will increase because your unit is using more power.

Can a central AC run without an air filter?

You can run central AC without an air filter, but you don’t want to let it go for more than eight hours. The air that flows through your house will contain dust, bacteria, pollen, mold, and more. Not using a filter can also damage your AC system.

Conclusion

There are different types of central air filters on the market. You can find the best one for your home depending on the material, reusability, and MERV rating. Make sure you check the filters to get the best air quality in your home and prevent your unit from malfunctioning.

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.

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