How To Insulate Ductwork In Attic

The attic and walls are one of the most important areas to insulate in any space.

How to insulate ductwork in attic.

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. Tape any punctures in the insulation s vapor barrier to prevent leaks. 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. When it comes to insulation ductwork matters too.

It was new when the ac was put in 7 years ago. If you want to cover metal ductwork with blown in insulation t hese steps must be followed in this order. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. The foam provides a vapor barrier so the ductwork won t sweat.

Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. Energy saver dealers 204 202 views. If necessary switch the wires to reduce the blower to its lowest speed. 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.

The duct insulation should include a vapor barrier cover. But what about the parts behind the walls and in the ceiling. Cover the metal ductwork with closed cell spray foam. I called out the original hvac company and they took a look and said they saw no water.

Avoid compressing the insulation. Plan to pull up the flooring and layer new insulation on top of the old. Because the simplest and cheapest way to insulate an attic is to add material to the floor. Check the speed of the blower motor on the furnace.

That s what happened to the ducts in the lead photo of this article. 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. Use metal flex or fiber board ducts that are insulated to code. Cover the spray foam with fire retardant spray.

Use a pressure sensitive vapor retarder tape designed for ductwork. Use a paintbrush to apply duct mastic to the joints where an elbow connects to a duct. Bury the ducts deeply in insulation. Most insulation relies upon the air space between its fibers to deliver the r value promised.

How to insulate the attic air sealing the attic energy saving attic insulation duration.