What are signs of mold in AC units?« Back to Previous Page

Based on my experience as a certified mold inspector here in Dubai, the signs of mold in AC units are often distinct, especially given our high humidity and constant AC usage.

The most common visual sign is black, brown, or greenish dust-like patches around the air supply vents, exactly as you've described. This "dust" is actually a accumulation of microbial growth and spores being blown out from the contaminated evaporator coils or ductwork. A persistent musty, earthy odor when the AC is running is another major red flag; that's the microbial volatile organic compounds (mVOCs) released by active colonies. Health-wise, if occupants experience unexplained allergy-like symptoms—such as the coughing you mentioned, along with sneezing, itchy eyes, or sinus congestion—that seem to improve when they leave the property, the AC is a prime suspect.

The UAE's high ambient humidity causes significant condensation within AC units. If the drain pan is clogged or the unit isn't maintained, this stagnant water becomes a perfect breeding ground for mold. Under DM regulations and guidelines like the Dubai Green Building Regulations, indoor air quality is taken seriously, and contaminated systems need to be addressed.

For a case like yours, with visible growth and health symptoms, I strongly recommend a professional inspection. DIY cleaning often just disperses the spores. We use borescopes to inspect inside ducts and air sampling to identify spore types and concentration levels. If confirmed, a full hygienization of the entire system is needed.

For a proper assessment, you can call our team at 800-MOLDS or email hello@saniservice.com.