How do you fix or prevent sweating on an air duct?

Answer by  jaho (47)

It sounds as though there is high humidity where the ducts are located. There are two approaches to fixing the problem. Installing a dehumidifier will take moisture out of the air, leaving less to condense upon a cold duct. The other approach is to identify the source of the moisture in the space and eliminate the source.

Answer by  kipcat (1964)

Sweating on duct work happens because the temperature of the duct work is below the dew point of the moisture in the air. Most of the time this happens where duct is run through an unheated basement. This problem can only be solved by heating the basement or insulating the duct.

Answer by  Stu780 (6)

Condensation or "sweating" occurs where there is a difference between hot and cold air on bare metal. If the duct has not been properly sealed at the joints, they should be screwed and taped. The duct should be insulated as well, properly stapled and taped and mastic applied.

Answer by  jim68 (44)

It is caused when hot air surrounds a cold object (improperly insulated ducts.) You can reduce the temperature of the surrounding air or provide better insulation.

Answer by  Amber40 (24961)

You should probably look into pipe insulation. You need to create a barrier of insulation to keep the damp air from hitting the pipes surface and condensing.

Answer by  chitraanilkumar (340)

Ducts sweat due to the outside surfaces of the ducts are below the dew point of the air in their immediate surroundings. The primary ways to stop ducts from sweating is to raise the surface temperature of the ducts.

Answer by  japratt (1687)

If your air duct seems to be sweating then you will need to provide more air so it will not do this.