Condensation is most commonly caused by a difference in temperature between the air conditioning duct and the air outside. Hot, moist air surrounding a cold air duct becomes condensed when it cools down, forming water droplets that can be seen as condensation around the ducts.Click to see full answer. People also ask, how do you stop condensation on ductwork? Reduce the humidity level around your air ducts. Keep ducts spaced apart so air can flow between them. Unblock any ducts that are restricting air flow and have them cleaned regularly. Keep your air filters clean and change them regularly. Repair leaking ducts. Secondly, why is my ductwork full of water? Clogged Condensate Drain Line The problem: If condensation accumulates within the air vent, it can cause water to drip from the AC vents. Sometimes when systems are installed in these areas, problems with the condensate drain can cause water to overflow from the drip pan and into the air ducts or air vents. Secondly, why do ducts sweat? Ducts sweat because 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 or to lower the dew point of the air surrounding the duct by some form of dehumidification.Should you insulate return ducts?Insulation is applied to ductwork to enhance thermal performance and prevent condensation and dripping. Return air ducts only need to be insulated if they pass through environments that adversely affect the return air temperature. Exhaust air ducts normally do not need insulation.