Insulating Ductwork In Attic Venting

Sometimes the insulation is inside the ductwork.

Insulating ductwork in attic venting.

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. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. Although both the attic floor and the ductwork are insulated ted recognizes the situation isn t ideal. Make sure the foil surface of the insulation is free of dust before applying the tape.

Other times insulation may be on the outside. The greater the temperature extreme between the air inside the duct and the air surrounding the ductwork the greater your need for duct insulation. Because the moving air is in the ductwork for only a short period of time it does not need the insulation r value the attic floor requires. Insulating hvac ductwork when insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value.

Flexible ductwork comes with different insulation r values. Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards that specify an r value of 8 for attic ducts and 6 for ducts located anywhere else. The 1 800 square foot brick ranch in climate zone 4 dates from the 1960s but the previous owner installed both a furnace and ductwork in the attic just four years ago.