The black dust may be patchy and difficult to wipe off.
What causes mildew around air conditioning vents.
If warm and humid air is coming from the attic this can cause condensation to form on the cold air ducts and leak.
You can see the same principle at work when you drink an icy beverage and water beads up on the outside of the glass.
Nobody wants moisture to turn into mold or mildew in their air ducts.
As cool air flows through the vents on hot days the moisture in the air can condense inside the air vent.
Air conditioner vents can be breeding grounds for black mold.
Mold in air ducts most commonly occurs when there is moisture inside the ductwork.
If you notice black dust around your air vents this could be a sign of black mold growing within.
You may need more duct or attic insulation in order to solve the problem.
Black mold has a distinctive unpleasant musty smell.
If there is black mold growing in your air vents you may notice a musty aroma when you run.
Black dust around air vents.
If you live in a wet climate such as a southern state or tropical country it is likely that you ve had to clean mildew off your bathroom walls basement floorboards or even from behind your wallpaper.
An unusual or musty odor is often the first sign of mold in air ducts or in air vents.
In many cases you ll smell it before you can see it.
Mildew can also often grow inside air conditioning vents.
If you notice a musty or moldy smell that goes away when you are not using your air conditioning or heating if they share ducts that can narrow the cause down to mold in your hvac system.
Condensation forms in the coils and ducts as cool air circulates through the system creating a habitat for moisture loving mold.