How To Insulate Ductwork In Attic

Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords.

How to insulate ductwork in attic.

That s what happened to the ducts in the lead photo of this article. Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. Use metal flex or fiber board ducts that are insulated to code. Check the speed of the blower motor on the furnace.

Make sure the foil surface of the insulation is free of dust before applying the tape. Tape any punctures in the insulation s vapor barrier to prevent leaks. Use a pressure sensitive vapor retarder tape designed for ductwork. If you want to cover metal ductwork with blown in insulation t hese steps must be followed in this order.

I called out the original hvac company and they took a look and said they saw no water. Bury the ducts deeply in insulation. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. 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. How to insulate the attic air sealing the attic energy saving attic insulation duration. 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 a paintbrush to apply duct mastic to the joints where an elbow.

Energy saver dealers 204 202 views. When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. Cover the metal ductwork with closed cell spray foam. The duct insulation should include a vapor barrier cover.

Most insulation relies upon the air space between its fibers to deliver the r value promised. Mechanically fasten and mastic seal all duct connections. Cover the spray foam with fire retardant spray. The foam provides a vapor barrier so the ductwork won t sweat.

The attic ductwork is flex duct work. It was new when the ac was put in 7 years ago. 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. Recently i had another hvac company come out and put in a new bathroom vent and they told me they believed the duct work was full of water.

Avoid compressing the insulation.