Insulating Heat Ducts In Attic

Our team follows a rigorous process for replacing ductwork.

Insulating heat ducts in attic.

Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. Other times insulation may be on the outside. Sometimes the insulation is inside the ductwork. Check the speed of the blower motor on the furnace.

Wrap fiberglass duct insulation around the ducts and tape the seams together. So logically the ducts deserve more not less insulation. Out with the old in with the new. First consider the duct location.

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. Unfortunately so many houses especially newer homes end up with ductwork running through the attic. Flexible ductwork comes with different insulation r values. If necessary switch the wires to reduce the blower to its lowest.

But whether you hire us or somebody else be sure your contractor follows these steps. 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 simplest and cheapest way to insulate an attic is to add material to the floor. Plan to pull up the flooring and layer new insulation on top of the old.

After all most new homes have r 49 insulation on the attic floor holladay continues. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. Replacing your ducts is another option when you ve got old uninsulated ones. But the air in the ducts is facing a delta t of maybe 100 f or 120 f a greater delta t.

A metal duct conveying cool conditioned air through a broiling attic in summer or warm air through a chilly crawl. Make sure the foil surface of the insulation is free of dust before applying the tape. When the attic is 20 f that insulation is addressing a delta t of 50 f. Use a paintbrush to apply duct mastic to the joints where an elbow.

Acute temperatures in these areas contribute to thermal loss in metal ductwork. 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. Of course you might also consider replacing your old ducts. 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.