Condensation Attic Ductwork

Persistent ductwork sweating may eventually lead to water damage.

Condensation attic ductwork. Ductwork located in an attic must be hung properly so that the insulation can do its job. It can also feed mold growth and cause ceiling joists to rot and sheetrock to disintegrate leading to unhealthy air quality in your home and the need for costly structural repairs. The 1 746 square foot house has r 19 insulation between the rafters and between r 15 and r 20 of rigid foam above the roof sheathing. Let s say your ductwork is in your attic.

This colder surface then chills the surrounding air to a temperature below it s dew point which causes the water vapor to condense into a liquid just like on the outside of a glass of iced teas sitting outside on a hot day. So if you see unusual water staining on any of the ceilings in your home and the roofer has eliminated roof leaks it is likely coming from some fault with the duct system in your home. Excessive condensation can also create conditions favorable to mold or mildew forming in areas surrounding the duct itself. Over time condensation dripping from your ductwork onto attic insulation can cause it to compress which lowers its r value.

Even though the air conditioning equipment appears to be operating normally humidity inside the house is between 60 and 65 and return ducts located in the attic show significant condensation. Condensation forms when warm humid air comes into contact with a colder surface like your air conditioner s ductwork. Occasional condensation on a c ducts is not a problem but keeping an eye on the situation is recommended. Condensation will begin to drip onto your attic insulation making it less effective at regulating temperatures inside your home.