How To Insulate Ductwork In Attic

The foam provides a vapor barrier so the ductwork won t sweat.

How to insulate ductwork in attic.

Make sure the foil surface of the insulation is free of dust before applying the tape. If necessary switch the wires to reduce the blower to its lowest. 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. I called out the original hvac company and they took a look and said they saw no water.

How to insulate the attic air sealing the attic energy saving attic insulation duration. The attic ductwork is flex duct work. Cover the metal ductwork with closed cell spray foam. Mechanically fasten and mastic seal all duct connections.

This isn t equivalent to bringing them into the conditioned space as you ll still have additional duct load but it s a lot better than having them in unconditioned attic space. That s what happened to the ducts in the lead photo of this article. Use metal flex or fiber board ducts that are insulated to code. Tape any punctures in the insulation s vapor barrier to prevent leaks.

Cover the spray foam with fire retardant spray. Use a pressure sensitive vapor retarder tape designed for ductwork. Bury the ducts deeply in insulation. If you want to cover metal ductwork with blown in insulation t hese steps must be followed in this order.

It was new when the ac was put in 7 years ago. Check the speed of the blower motor on the furnace. Avoid compressing the insulation. 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.

Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. Most insulation relies upon the air space between its fibers to deliver the r value promised. 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. Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct.

Because the simplest and cheapest way to insulate an attic is to add material to the floor. The duct insulation should include a vapor barrier cover. Energy saver dealers 204 202 views. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place.

Plan to pull up the flooring and layer new insulation on top of the old.