Why Does My AC Smell Musty?

You start the air conditioner and the condo smells like a damp closet for the first few minutes. In Aventura, Miami Beach and Fort Lauderdale that complaint is routine. The cause is usually moisture plus dust, and it is usually inside the air handler.

Where the smell comes from

The evaporator coil is cold whenever the system runs. Humidity in the air condenses on it and should drain away through the pan and the condensate line. Dust that lands on those wet surfaces stays wet. That film is what you smell when the blower first pushes air into the rooms.

A dirty vent cover can look bad and still not be the source. Wiping the grille does not clean the coil behind it.

What you can check before you call

• Look at the filter. A filter that does not fit, or one that has not been changed in months, lets the coil load up.
• If the air handler is in a closet, open the door when the system is off and see whether the closet itself smells. A strong odor there points at the cabinet, not the bedroom vent.
• Look for water under the air handler. A pan that does not drain keeps the cabinet wet, and cleaning alone will not hold if the clog returns.
• Notice whether the smell fades after the system has run for a while. A startup odor often means the wet parts are the problem.

What cleaning can and cannot do

HVAC cleaning removes the film on the coil, blower and drain pan. HVAC mold treatment is the visit when that wet equipment is the source of the smell. Air duct cleaning removes debris in the runs so it is not blown back onto a clean coil.

We do not test for mold. Looking at a dirty coil is not a lab result. If you see growth on drywall, ceilings or insulation, that is outside the air conditioner and needs a qualified remediation contractor.

If a building leak or a clogged drain keeps the system wet, the smell can come back after a thorough cleaning. We will tell you if that is what we find.

Purify Air Duct Cleaning serves Aventura and nearby cities seven days a week. Call 954-945-9428 or see our Hollywood, Fort Lauderdale and Hallandale Beach pages.