How to Clean an Air Filter: Step-by-Step Guide

Your air purifier or HVAC system can only perform well when its air filter allows. With a dirty air filter, you have to compromise on its performance and even cause long-term damage. Fortunately, with just a bit of maintenance, you can extend the life of your air filters.

It's time to slide into the detailed steps for 'How to clean an air filter properly' whether it’s from an air purifier or home HVAC unit, air conditioner or furnace.

Why Is Cleaning an Air Filter Important?

Air filters, which are different from air purifiers, trap dust, pet dander, mold spores, and pollen over time. If not cleaned regularly, filters can become clogged and lead to:

● Reduced airflow and HVAC efficiency

● Poor indoor air quality

● Increased energy consumption

● Wear and tear on mechanical components

● Air filters can trap odor-causing particles, especially in homes with pets or smokers.

Types of Air Filters

Get the best air filters and accessories from Abestorm. All air filters are not meant to be cleaned, so read the instructions carefully. There are usually two types of filters:

Disposable Air Filters

Usually, residential air filters are disposable as they are made of pleated paper, fiberglass, or synthetic materials. They are made for single use and if you wash them, it will be damaged. You just have to replace disposable filters after a certain period of time and according to the manufacturer instructions.

Reusable (Washable) Air Filters

Reusable air filters are made of electrostatic or washable synthetic materials, and are a more environmentally friendly and cost-effective option in the long run. Their initial cost is higher but they pay for themselves over time as you avoid purchases of disposable filters.

You should clean washable air filters every 1-3 months, depending on the manufacturer instructions, HVAC unit, house occupancy, pets, allergies, etc.

Here are a few categories of air filters that are usually used. Make sure to check the manufacturer's label before making a purchase:

Things You’ll Need to Clean Air Filters

● Warm water

● Mild dish soap or detergent

● Soft brush (optional)

● Vacuum cleaner with brush attachment

● Garden hose (for larger filters)

● Microfiber towel or drying rack

How to Clean a Reusable Air Purifier Filter

Here is the step wise process to clean a reusable air purifier filter:

Step #1: Power Off and Unplug

Turn off the air purifier and unplug it for safety. Place it on a flat surface where you can work comfortably.

Step #2: Open the Filter Compartment

Open the back or side panel of the unit to access the filters. Most models have a pre-filter, HEPA filter, and sometimes a carbon filter.

Step #3: Remove and Inspect the Filters

Take out the filters carefully. Check if they are labeled as washable or reusable. Disposable filters should be replaced, not cleaned.

Step #4: Clean the Filters

For washable filters, gently vacuum both sides to remove dust. Then rinse with cool water. Avoid using soap unless the manufacturer recommends it.

Step #5: Dry Completely Before Reinstalling

Let the filter air dry completely. This can take several hours. Never reinstall a damp filter as it can cause mold or damage the unit.

How to Clean a Home HVAC or Furnace Air Filter (Reusable)

Here is the best way to clean reusable HVAC filter:

Step#1: Power Off Your HVAC System

Before you do anything, turn off your HVAC, furnace, or air conditioner completely. This prevents the system from cycling on while the filter is removed and protects you from any moving parts.

Step#2: Locate and Remove the Air Filter

Air filters are typically located at the air handler. Look for a slot or a dedicated compartment near where the return air duct connects to your furnace or air handler. Sometimes, the filter is located behind a large return air vent on a wall or ceiling. Carefully slide out the dirty filter.

Step#3: Initial Debris Removal

Take the filter outdoors, if possible, and gently tap it against a hard surface to dislodge loose dust and larger debris. You can also use a vacuum cleaner with a brush attachment to lightly vacuum both sides of the filter to remove surface dirt.

Step#4: Prepare for Washing

If the filters are mildly dirty,you only need water pressure and if they are heavily soiled, fill a tub of lukewarm water/ Then add a few drops of mild dish soap or the recommended filter cleaning solution.

Step#5: Wash the Filter

For how to wash an air filter, follow the steps:

●  If you are cleaning outdoors, use a garden hose with a spray nozzle and spray water through the filter against the direction of airflow until the water runs clear.

● If you are washing indoors, submerge the filter in the soapy water. Allow it to soak for 10-15 minutes to loosen stubborn grime. Then, using your soft-bristled brush, gently scrub both sides of the filter to remove any remaining dirt.

Step#6: Rinse Thoroughly

Rinse the filter completely under clean, running water (again, against the direction of airflow) to remove all traces of soap and dirt. The water running off the filter should be crystal clear.

Step#7: Let It Dry

Never reinsert a damp or wet air filter into your HVAC system. Moisture can promote mold growth within your ducts and even damage your system's electrical components. So, gently shake off excess water and place the filter on a clean towel. Allow it to air dry completely. This can take several hours, or even a full day.

Step#8: Reinstall the Clean, Dry Filter

Once the filter is completely dry, slide it back into its slot in the correct orientation. Most filters have an arrow indicating the direction of airflow; ensure this arrow points towards your furnace or air handler.

How Often Should You Clean an Air Filter?

● HVAC or Furnace Filter: Every 1–3 months depending on usage and environment.

● Air Purifier Filter: Every 1–2 months for reusable filters.

● Pet Owners or Allergy Sufferers: Consider cleaning more frequently.

When to Replace Air Filters Instead of Clean?

Cleaning is only effective if the filter is designed for reuse. Replace your filter if  it is made of paper or other non-washable material or you see tears, holes, or frayed edges. You can also replace it if it still looks clogged or discolored after cleaning or the airflow is still poor even after drying.

Final Thoughts

Learning how to clean an air filter properly can save you money, improve your equipment’s performance, and keep your air healthier. Just make sure to check whether your filter is washable before you begin. Whether it’s your air purifier, HVAC system, or furnace, a clean air filter is one of the easiest and most effective ways to keep everything running smoothly.