How to Clean an Air Purifier Filter?

Any filter can be clean...... well almost. If you own a Honeywell, Bionaire, or GermGuardian models, you need to make sure it is in tip-top condition. The cleaner the air purifier, the more airborne particles it can take in. In this post, we are going to glide through the few ways of keeping the filter nice and clean without lifting a finger. After all, what's the point of having an air purifier when itself is filled with dust and dirt?
Short answer
Unplug, vacuum air inlet, outlet, and pre-filter every 2-3 weeks.

Before You Get Started (Pre-care)

  • Check if you have the right tools, right weather, and time need. Cleaning an air purifier can sometimes be time-consuming.
  • Make sure the filter can be clean. Most pre-filter or permanent filter is washable to a certain extent. Check the product manual for more details.
  • Most HEPA filter/ carbon filter cannot be clean and require direct replacement. Same goes with carbon pre-filter.
  • Never use glass cleaners, detergents, or dishwasher to clean the filters. Do not wash the filters with a washing machine.
  • Replace filter instead if is worn out or damaged.
  • Be careful not to drop your cleaning tools into the air inlet/ outlet. Also never obstruct any opening of an air purifier.
  • Check if the cord or plug is damaged. If it is, stop cleaning and get it sorted before resuming the operation.
  • Air purifier should be used in room temperatures between 40° F (4° C) and 110° F (43° C) unless stated otherwise in manual.
  • Make sure your hand is not wet during the whole cleaning progress. We do not want to soak the filter with dripping water.
Most HEPA/ carbon filter requires interval replacing annually. Regularly cleaning a pre-filter will extend the other filter’s lifespan. It will also protect the air purifier from short-circuiting due to compromised ventilation.

Exterior Cleaning

  • Turn off and unplug the air purifier before anything else. Some models will take a few seconds before it dies off.
  • Start by using a soft, damp rag or better yet microfiber cloth and wipe any opening. For ventilation, use a soft brush to dust off narrow gaps.
  • Focus on the gap in air inlet and outlet that is usually filled with dust.
  • For stains that are not easily removable, apply a little bit of soap or mixture of water and lemon. Scrub it off with a damp cloth.
  • For plastic cover or grill that is removable, you can soak it in water and let it dry before installing it back. It’s way faster than cleaning through every single hole.
  • Repeat the steps every 2-4 weeks or when necessary.

How To Clean Air Filter (Permanent or Pre-filter)

  • First and foremost, turn off and unplug the air purifier before cleaning. Move the device to an open space area before removing the filter. This can reduce the dust or allergens from being re-released into the same space.
  • Depending on the model, Remove the front, back or bottom panel to gain access to the filter. Most cover can be snap open easily. If not, you might be doing the wrong way or the panel is damage (dent/ bend).
  • Check the permanent filter condition. If there is a noticeable amount of dust, lint or particulate accumulation, remove the filter by pulling the tab.
  • If the filter is lightly discolored or yellowish, is perfectly normal due to oxidization.
  • You can use a handheld vacuum at low speed and gently brush through the filter.
  • For more stubborn particulates, gently wash it by hand in warm soapy water.
  • If the air purifier comes with humidifying filter, soak the filter in a sink or bucket filled with normal temperature water. Wait at least 10 minutes and dab it with a soft cloth.
  • Leave the filter drip dry remove installing back to the air purifier. Avoid using hairdryer or dryer as the heat might damage the filter.
  • We recommend cleaning the permanent/ pre-filter every 30 days or so. You can adjust the time frame if you notice there is a dip in the airflow performance.
  • Some air purifiers come with filter check indicator. If the light lit up, it’s time to perform the cleaning.

Finally, insert back the filters according to the previous arrangement. Usually, there will be an arrow pointing on which side of the filter should be oriented. Turn on the air purifier and let it run on max speed for an hour. If there is grumbling or weird creaking sound, see if there is any displacement on the filters. If everything sounds normal, congratulations your air purifier is completely clean.

There are 8 types of air cleaner in the market. An air purifier that utilizes a mechanical filter will not perform its best when there is an overload of contaminants in it. This includes dust, dust mites, mold, spore, pollen, pet hair, dander, smoke, and germs. The clogged air vents and filter will affect its airflow distribution and CADR. The motor will work harder to compensate the losses in airflow thus reducing the air purifier lifespan. In a worst-case scenario, the collected contaminants will be dispersed back into the air. This defeat the entire purpose of owning an air purifier.

This is a general guideline of how to clean your air purifier. We recommend going through the product manual at least once to see if there are any unique steps that you need to be aware of.


Max Fernandez

A loving father and a dedicated reviewer for airfuji.com with more than 1000 air purifiers under his belt. Max Fernandez is also one of the million patients currently suffering from asthma. Feel free to nudge him if you have any questions.