Quick answer
Mini-split deep cleaning removes the mold, dust and slime that build up on the blower wheel, coil and drain pan of ductless indoor units. It fixes musty smells, black specks blowing out, weak airflow and dripping. Miami humidity makes these units especially prone to buildup.
Written by Sylvia Denton, HVAC Guides Editor. Updated 2026-09-22.
A mini-split indoor head pulls room air across a cold coil with a barrel-shaped blower wheel. Moisture on the coil and blower attracts dust and grows mold, which then blows back into the room.
Regular filter cleaning helps, but it does not reach the blower wheel or the back of the coil. Over a year or two in Miami, the buildup can choke airflow and cause dripping.
A deep cleaning uses a protective bag and a cleaning solution to wash the coil, blower wheel and drain pan in place, followed by a rinse and a drain flush.
