Condensation In Attic Ductwork

Vapor barrier on the attic side of the duct s insulation is compromised.

Condensation in attic ductwork.

Condensation on air ducts can be a serious problem. When the hot humid attic air contacts the cold duct or the cold duct boot the moisture in the air condenses on the cold surface just like the condensation that happens on a cold can of beer. Ductwork located in an attic must be hung properly so that the insulation can do its job. Over time condensation dripping from your ductwork onto attic insulation can cause it to compress which lowers its r value.

Dripping condensation may also lead to a ceiling leak which not only looks bad but also rots drywall and can cause your ceiling to collapse over time. Even if the insulation layer is at the attic floor you ll probably be better off making the roof the pressure boundary of the house in which case the absolute moisture levels but not the temperature of the attic will track that of the conditioned space below which should reduce the condensation potential dramatically. 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. Moisture goes right through the fiberglass insulation and condenses on the inner liner drips on ceiling below after building up.

The more the insulation compresses the less it can insulate your home. Condensation will begin to drip onto your attic insulation making it less effective at regulating temperatures inside your home. 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. As the humidity level rises outdoors condensation will gradually begin to form on the surface of your air conditioning ducts.

At the end of the day there are really only two causes for condensation on ductwork. The weight and dampness can compress the insulation reducing the insulation s r value. There are two main ways to solve this problem. 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.

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 colder the air is inside the duct the greater the chance of ductwork sweating. Both of these are easily treatable. When ductwork is touching it forms a very cold spot where they are touching thus condensation begins.

The air in your vented attic is hot and humid just like all outdoor air in florida. Improperly insulated ductwork and excessive moisture in the air. It s a natural process and similar to the way a chilled soda begins to sweat once you take it out of the refrigerator on a hot day. Remember that condensation can cause all sorts of problems from leaks to mold infestation so take the time to address this problem as soon as you can.