How do we de-stink our air conditioner?

May 12, 2021 5:16 PM

Our Mitsubishi mini-split smells bad at certain times. I've read about dirty-sock syndrome and understand something must be cleaned, but I'm not sure what or how to do it. The manual is completely unhelpful on this point.

Our mini-split has a heat function and that never smells, and it doesn't smell when it's really cranking cold. But when the temperature inside matches the set temperature for the unit, the stink shows up and the humidity also seems to increase (though I haven't measured so maybe not). I've seen numerous things to buy on Amazon that seem to involve a big plastic bag and soaking down the indoor unit, but is that the correct thing to do? We've replaced the replaceable filters and cleaned the screens, but this is clearly something deep in the guts of the machine. I've never had a house with any sort of AC before so this is all new to me.

posted by oneirodynia to Home & Garden (2 answers total)

Best answer: You will need to clean the blower wheel of the mini split indoor unit. The filters in the indoor unit are not sufficient to completely prevent mold from growing inside the unit. During the winter (when you're heating), humidity is relatively low, so mold isn't prominent. During the summer (when you're cooling), humidity is reduced when the unit is actively cooling. However, when the unit is more or less stable, it will be somewhat humid and mold can grow.

You can either remove and clean the blower wheel and drain pan of the unit or use the "giant bag and hose down the unit" approach. Both approaches are described here. The remove/clean approach is more complicated, but less messy. The giant bag approach is less complicated, but more messy.
posted by saeculorum at 5:29 PM on May 12, 2021 [4 favorites]

Response by poster: Great, that is exactly what I needed. Thank you!
posted by oneirodynia at 11:10 AM on May 13, 2021 [1 favorite]