Heating & Cooling

How to Clean Ductless Mini Split Air Filters

ductless wall lg

Ductless mini-split heat pumps offer convenience and energy savings for small areas where traditional heat pumps are not practical. However, you’ll still have to perform regular maintenance on your ductless heat pump to keep it running smoothly. The number one maintenance item is keeping the air filters clean.

Ductless heat pumps have air filters located inside the interior wall unit. The air filters need to be inspected and cleaned every two weeks by rinsing them with water. It would be best to clean the air filters to maintain optimal airflow, efficiency, and indoor air quality.

Here’s how to clean the air filters in your ductless mini-split heat pump system:

  1. Turn off the power to the unit
  2. Wipe down the interior
  3. Remove the air filter
  4. Clean the air filter
  5. Allow the air filter to dry
  6. Replace the air filter
  7. Turn the power back on

How to Clean Your Ductless Air Filters

This article will teach you everything that you need to know about the cleaning process, including:

  • Every step to clean your filters quickly and efficiently
  • Frequency suggestions for cleaning
  • Whether you should replace or clean your filters

Turn off the power to the unit

Cutting the power to the machine is the most critical step. It’s not a good idea to run your ductless heat pump without an air filter installed. When the unit is running, it draws air into the system, where the filter prevents dust and dirt from collecting inside the unit.

Wipe down the interior

There might be a little bit of dust or debris on the ledge and the inside of the lid. Wipe down the surface and remove the filter from the pump. It would be best to replace the lid or close it to prevent anything from floating inside. When the filter isn’t in it, there’s nothing to protect your heat pump.

Remove the air filter

Unlike traditional HVAC systems, ductless heat pumps have two reusable air filters. Locate the air filters on the front of the system in front of the internal coil.

To remove the air filters, open the front cover by depressing the sides and lifting the cover till it latches open. Depress the clips on the air filters, then pull them down and out to remove them.

Clean the air filter

Once you’ve removed the air filter, please take it to a kitchen or utility sink to clean the filter. Using a sprayer, rinse the filter under low-pressure running water.

Dilute liquid or powder detergent in half a gallon of water. You should only use about one teaspoon or less, depending on the size of your filter. Dip it into the warm water and detergent solution using a sponge, then scrub the filter down thoroughly. Once you’ve removed all of the dust and debris, wash it off with more warm water in the sink.

Insiders Note: You could also use the AIRCONcare Organic Air Conditioner Cleaning Kit available at Amazon if you want to have a complete kit ready to go. It’s as simple as spraying, rinsing, and drying it in a few minutes.

Allow the air filter to dry

It’s essential to make sure the air filter is completely dry before reinstalling it. Please don’t place the air filter in direct sunlight to dry since it can weaken the material. Place the air filter on a towel to dry naturally.

It’s essential not to place a wet air filter back into your ductless system as it can clog faster, preventing proper airflow into the system.

Install the clean air filter

Once the filter is clean and dry, you can replace it with the ductless mini-split heat pump. Be sure to install the filter as directed by the airflow arrows on the filter frame. Some filters will only install in one direction to prevent improper installation.

Turn the power back on

Once you install the air filter, secure the lid, and turn the power back on. Verify that the air flows through quickly. If it does, then you’re all set.

Thinking about doing a DIY ductless heat pump installation? See our Installing a Ductless Heat Pumps: A DIY Guide

How Often Should You Clean Your Ductless Heat Pump Air Filter?

You should clean the air filter in your ductless heat pump once every two weeks. You don’t necessarily have to clean the filters every two weeks if you don’t use them often. The goal is to check it that often to ensure that it’s still allowing air to flow through.

If you live in a dusty or humid climate, then you might have to clean it weekly. However, most homeowners will only have to clean their filters once a month or so.

You might’ve read above that you should perform an inspection on your filters every two weeks or so. Several factors can change the frequency of each cleaning, so we’ll break them all down below to paint a clear picture of what you can expect.

  • Humid, rainy environments can cause your filter to need regular cleanings. Unlike what most people believe, heat pump filters can become dirty from mold rather than dust alone. You might not even find any dust, but it can be ridden with mildew and mold in a matter of weeks.
  • Dusty towns, such as those found in the deserts of Arizona, California, Utah, or Nevada, can increase the number of cleanings for your filter. Sand, dirty, and dead plants can clog up the filter, which means you might have to clean it every week. Again, it depends on how severe the wind is in your area.
  • Changing seasons and weather can directly affect your heat pump filter. Wind, rain, snow, and other weather patterns might make you have to clean it more or less. The best environment for ductless mini-split heat pump filters would be dry, moderate temperatures, and with very little wind, dust, or pollen.

You are failing to clean your filter as often as it should damage the heat pump. It can also make you have to replace it more frequently than you’d usually have to. Cleaning might not be the most exciting chore, but it’ll save you money.

If your filter isn’t looking too good and you’re curious about whether or not it’s time to replace it, proceed to the next section.

Should You Clean or Replace It?

Knowing if you should clean or replace it can be done by looking for the telltale signs of a dirty, damaged filter.

You should only need to replace the air filter if it is damaged or will not come clean. These air filters are designed to be reused and can last several years. Replacing a filter isn’t too expensive compared to other HVAC-related issues, but it’s never fun to spend money when you don’t have to.

Ductless heat pump filters are semi-permanent. These air filters can last up to 2 to 5 years, but they tend to cost well over $100. Ask your HVAC technician about the possible options while installing the unit, or call the company if it’s already installed.

If you notice that the mesh is loose or indented, it could mean that it’s about to give way. Ripped filters should always be replaced, regardless of how old they are. The gap left behind will be big enough to let dust right through, ruining the filter’s purpose.

You can order replacement air filters from the manufacturer. Most companies will have a website or customer service number on the data tag. If not, a Google search should point you to the manufacturer’s website.

You may also be interested in our 11 Best Uses for a Ductless Heat Pump. This article looks at the 11 best applications for ductless heat pump units.


Ductless mini-split heat pumps have all sorts of benefits, including the fact that they save you money. Cut your expenses even more by performing routine, scheduled cleanings to increase their longevity. Remember that you can hire a professional to clean it for you if you want to see the step-by-step process before you do it yourself.

Here’s a quick recap of the article:

  • Step-by-step instruction on how to clean your air filter
  • You should inspect the air filter every two weeks.
  • Disconnect the power, wipe the ledge, remove the filter, clean it with detergent, and let it air dry before putting it back into the unit.
  • Replace your filter every 2 to 5 years or if the air filter becomes damaged.

Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.