How to Clean Mini Split Filters

Routine maintenance keeps your ductless mini split running efficiently, and the most important task is cleaning the air filters. Dirty filters restrict airflow, forcing the system to work harder, raising energy use and utility bills, and leading to costly repairs. Mitsubishi, Fujitsu, Daikin and most other ductless mini split manufacturers recommend cleaning the filters every few weeks.

The Two-Week Rule

Because of how mini split filtration is designed, clean the main air filters every two weeks. Units that run less often may not need cleaning as frequently. To check, turn the unit off and open the front panel to look at the filters.

How to Clean Mini Split Filters, Step by Step

1. Turn off the unit. Always power off your mini split before removing the filters. Running it without filters circulates unfiltered air and lets dust reach the coil.
2. Remove the filters. Open the front panel of the indoor unit and slide out the filters. Many units have two or more, so remove them all. A few models need a screwdriver to lift the cover.
   Tip: Check that the filters are still in good condition. If they're torn, warped or brittle, it's time for a replacement filter.
3. Vacuum the filters. Use a vacuum with a soft brush attachment to gently remove loose dust and debris.
4. Wash the filters. If grime remains, rinse the filters under lukewarm water, or soak them for tougher buildup. Don't scrub hard.
5. Dry them completely. Let the filters air-dry fully before reinstalling. Don't dry them in direct sunlight, which can warp the plastic frame, and make sure they're completely dry to prevent mold.
6. Reinstall or replace. Put the clean, dry filters back in place. If a filter is still dirty after cleaning, replace it.

Filters You Replace Instead of Wash

Many mini splits also have secondary filters, such as anti-allergy enzyme, deodorizing, Nano Platinum, Apple Catechin or photocatalytic filters. These aren't washable and should be replaced on the manufacturer's schedule, usually once a year. Our annual filter bundles include every filter a given model needs for a year.

Professional Maintenance

Regular filter cleaning doesn't replace professional service. Have your mini split serviced twice a year to keep it safe, efficient and long-lasting. Also keep the area around the outdoor unit clear of leaves and debris, which block airflow and reduce efficiency.

Find the Right Replacement Filter

Not sure which replacement filter your unit needs? Find the model number on the indoor unit's nameplate, typically on the right-hand side of the unit or on the bottom edge facing the floor. Then see our mini split filter buying guide or look up your model in the Mitsubishi Filter Finder. Can't find it? Send us a photo of your nameplate and we'll match the right part.