How To Insulate Ductwork In Attic

Cover the spray foam with fire retardant spray.

How to insulate ductwork in attic. It was new when the ac was put in 7 years ago. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. I called out the original hvac company and they took a look and said they saw no water. Avoid compressing the 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. Use metal flex or fiber board ducts that are insulated to code. 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. Mechanically fasten and mastic seal all duct connections.

The attic and walls are one of the most important areas to insulate in any space. Tape any punctures in the insulation s vapor barrier to prevent leaks. Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. That s what happened to the ducts in the lead photo of this article.

When it comes to insulation ductwork matters too. But what about the parts behind the walls and in the ceiling. Bury the ducts deeply in insulation. 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.

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. Energy saver dealers 204 202 views. The attic ductwork is flex duct work. The duct insulation should include a vapor barrier cover.

If necessary switch the wires to reduce the blower to its lowest speed. Use a paintbrush to apply duct mastic to the joints where an elbow connects to a duct. Cover the metal ductwork with closed cell spray foam. The foam provides a vapor barrier so the ductwork won t sweat.

Plan to pull up the flooring and layer new insulation on top of the old. Use a pressure sensitive vapor retarder tape designed for ductwork. Check the speed of the blower motor on the furnace. 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.

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