How To Insulate Ductwork In Attic

Because the simplest and cheapest way to insulate an attic is to add material to the floor.

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. The attic and walls are one of the most important areas to insulate in any space. 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. When it comes to insulation ductwork matters too.

If you want to cover metal ductwork with blown in insulation t hese steps must be followed in this order. Use a pressure sensitive vapor retarder tape designed for ductwork. Most insulation relies upon the air space between its fibers to deliver the r value promised. The duct insulation should include a vapor barrier cover.

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. That s what happened to the ducts in the lead photo of this article. 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. If necessary switch the wires to reduce the blower to its lowest speed.

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. The attic ductwork is flex duct work. Avoid compressing the insulation. But what about the parts behind the walls and in the ceiling.

Cover the metal ductwork with closed cell spray foam. Use metal flex or fiber board ducts that are insulated to code. Energy saver dealers 204 202 views. Plan to pull up the flooring and layer new insulation on top of the old.

Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. Use a paintbrush to apply duct mastic to the joints where an elbow connects to a duct. It was new when the ac was put in 7 years ago. How to insulate the attic air sealing the attic energy saving attic insulation duration.

Check the speed of the blower motor on the furnace. Mechanically fasten and mastic seal all duct connections. Bury the ducts deeply in insulation. 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.

I called out the original hvac company and they took a look and said they saw no water.