For a small patch (under one square meter), you can clean it yourself. Wear an N95 mask and gloves. Isolate the area and avoid spreading spores. Scrub with a solution of detergent and water, then disinfect with a diluted bleach solution (one part bleach to ten parts water). Dry the area completely within 24-48 hours using fans or a dehumidifier to prevent immediate regrowth.

However, the visible patch is often just the surface manifestation. The leak from your AC unit is the root cause. If the condensation leak is internal to the ductwork or the drain pan is blocked, moisture will continue to seep into the building materials, and the mold will return. This is a very common scenario here.

Given the location on the ceiling and the ongoing AC leak, a professional assessment is strongly recommended. They can identify the exact source of the condensation, assess if the mold has spread into the ceiling cavity or AC system itself, and ensure it is remediated according to DHA and Dubai Municipality standards for indoor air quality. The most effective solution addresses the moisture problem first, then the contamination.