Insulated Ductwork For Attic

When these ducts are exposed to exterior air the plastic jacket never gets cold enough to permit condensation because the hot attic air keeps the plastic jacket warm.

Insulated ductwork for attic.

Is it ok to do it. Although both the attic floor and the ductwork are insulated ted recognizes the situation isn t ideal. Hvac ductwork is typically visible in your attic especially flexible ductwork. Summer hasn t even arrived he notes in a post at gba s q a forum and when the temperature outside climbs to more than 95 f the temperature in the attic tops 120 f.

Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. When hvac ducts are installed in a vented attic in a dry climate bury the ducts in attic insulation to protect them from temperature extremes in the unconditioned attic space. The greater the temperature extreme between the air inside the duct and the air surrounding the ductwork the greater your need for duct insulation. The shiny vapor barrier will protect the ductwork from sweating as long as it s exposed to the surrounding air.

The duct insulation should include a vapor barrier cover. Covering ductwork with insulation. Today s flexible ductwork is covered with a shiny metallic cover this is its vapor barrier. First consider the duct location.

Unfortunately so many houses especially newer homes end up with ductwork running through the attic. Check the speed of the blower motor on the furnace. Most attic ducts are insulated flex ducts that is flex ducts with r 6 or r 8 fiberglass insulation along with an exterior polyethylene jacket. If necessary switch the wires to reduce the blower to its lowest speed.