Insulating Heat Ducts In Attic

Of course you might also consider replacing your old ducts.

Insulating heat ducts in attic.

Make sure the foil surface of the insulation is free of dust before applying the tape. Use a paintbrush to apply duct mastic to the joints where an elbow. A metal duct conveying cool conditioned air through a broiling attic in summer or warm air through a chilly crawl. Out with the old in with the new.

Unfortunately so many houses especially newer homes end up with ductwork running through the attic. 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. Because the simplest and cheapest way to insulate an attic is to add material to the floor. Our team follows a rigorous process for replacing ductwork.

First consider the duct location. Sometimes the insulation is inside the ductwork. Wrap fiberglass duct insulation around the ducts and tape the seams together. Check the speed of the blower motor on the furnace.

If necessary switch the wires to reduce the blower to its lowest. Other times insulation may be on the outside. But whether you hire us or somebody else be sure your contractor follows these steps. Replacing your ducts is another option when you ve got old uninsulated ones.

When the attic is 20 f that insulation is addressing a delta t of 50 f. But if the floor is covered in plywood you can t stuff enough insulation beneath it to do the job sufficiently not even in warm climates. 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. Plan to pull up the flooring and layer new insulation on top of the old.

The greater the temperature extreme between the air inside the duct and the air surrounding the ductwork the greater your need for duct insulation. So logically the ducts deserve more not less insulation. When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. After all most new homes have r 49 insulation on the attic floor holladay continues.

Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. 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. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. 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.

Flexible ductwork comes with different insulation r values.