Mini-split upkeep
Mini-split filter schedule by brand
Pick your brand to see how often it says to wash the filters, how to wash them, and when the inside needs a professional deep clean.
Mitsubishi
Every 2 weeks (EZ FIT ceiling cassette)
Source: Mitsubishi help center, checked .
In New Orleans: start at every 2 weeks, and stretch it only if the filters come out clean.
Mitsubishi says not to use water hotter than 122°F or soak them more than 2 hours, and that running without filters can cause a malfunction.
Daikin
Every 2 weeks
Source: Daikin, checked .
In New Orleans: start at every 2 weeks, and stretch it only if the filters come out clean.
Daikin says to vacuum them first. If they're very dirty, wash them in lukewarm water with detergent and dry them in the shade.
Fujitsu
Every 2 weeks under normal use
Source: Fujitsu manual, checked .
In New Orleans: start at every 2 weeks, and stretch it only if the filters come out clean.
Fujitsu says to use warm water with a neutral detergent, dry them in the shade, and always run the unit with the filters in.
LG
Every 2 weeks
Source: LG, checked .
In New Orleans: start at every 2 weeks, and stretch it only if the filters come out clean.
LG says some of its fine-dust filters must not be washed with water. Check which kind you have before you rinse.
Carrier
Inspect and clean every 4 to 6 weeks
Source: Carrier, checked .
In New Orleans: start at every 4 weeks, and stretch it only if the filters come out clean.
Carrier says to vacuum them or wash them with mild soap, and let them dry completely.
Gree
Once a month
Source: Gree, checked .
In New Orleans: start at once a month, and stretch it only if the filters come out clean.
Gree says to rinse or vacuum them, and not to scrub them with a brush or put them in the dishwasher.
Senville
Every 30 to 60 days; every 2 to 4 weeks with pets, allergies, or dust
Source: Senville, checked .
In New Orleans: start at every 30 days, or every 2 weeks with pets, allergies, or dust, and stretch it only if the filters come out clean.
Senville says not to dry them with a hair dryer, a heater, or direct sun, and not to run the unit without them.
MRCOOL
Every 4 to 6 weeks
Source: MRCOOL, checked . Another MRCOOL page says every 1 to 3 months, depending on use. (MRCOOL filter sizes and maintenance)
In New Orleans: start at every 4 weeks, and stretch it only if the filters come out clean.
MRCOOL says to use warm water and mild detergent, and to let them dry completely before they go back in.
Other / don't know
Your manual decides. ENERGY STAR says to clean them when they look dirty or the filter light comes on.
Source: ENERGY STAR, checked .
In New Orleans: start at every 2 weeks, the most common interval among the brands here, until you find your manual, and stretch it only if the filters come out clean.
How to wash them
- Turn the power off at the breaker.
- Lift the front cover and slide the filters out.
- Vacuum the loose dust off first.
- If they're still dirty, wash them in lukewarm water with a little mild dish soap. Never use hot water. Rinse the soap out.
- Let them air dry in the shade. No hair dryer, heater, or direct sun.
- Slide them back in dry, close the cover, and turn the power back on.
Never run the unit without the filters while they dry. Mitsubishi says that can cause a malfunction, and Fujitsu says to always run with the filters in.
The filters guide has the full steps, with each brand's own words.
Why New Orleans starts at the short end
A mini-split here cools for most of the year, and the air is wet. The city's normal humidity at 6 a.m. is 88%, according to NOAA. The filters load faster than a calendar month suggests, so start at the short end of your brand's range. If they come out clean every time, stretch it.
When the inside needs a deep clean
Clean filters protect the coil, but they don't clean it. Each time you wash the filters, shine a flashlight up through the louvers at the blower wheel, the long round fan inside. A light film of dust can wait. Dark spots or a thick coat mean the inside needs a professional deep clean. That look comes from PNNL's Building America Solution Center.
Not sure what you're seeing? Take the cleaning check.