Black spots near AC vent: DIY or call a pro?« Back to Previous Page

Black spots near the AC vent are almost certainly mould growth, a common issue here due to Dubai's high humidity and constant AC use. The damp smell confirms it's active. Vinegar is a mild fungistat but often fails on porous surfaces like drywall where roots penetrate.

For a small, surface-level patch, you can try a stronger DIY approach using a solution of diluted bleach (1 part bleach to 10 parts water) or a commercial mould remover. Always wear gloves, a mask, and ensure good ventilation. Scrub the area thoroughly and let it dry completely.

However, if the spots reappeared after vinegar, the growth is likely more established. The main concern isn't the visible spot on your wall but the contamination inside the AC unit and its ductwork. The unit's cold evaporator coil produces condensation, creating a perfect damp environment for mould to thrive out of sight. Cleaning the vent cover alone is a temporary fix.

A professional inspection is recommended to assess the AC unit itself. They can check the drainage pan for blockages, clean the coil, and inspect the insulation lining the ducts, which is a common food source for mould. Proper remediation involves treating the entire system to prevent spores from continually blowing back into the room. In many cases, a full system clean and treatment by a certified provider is the only way to resolve the issue and the odour permanently.