How To Insulate Ductwork In Attic

Use a paintbrush to apply duct mastic to the joints where an elbow connects to a duct.

How to insulate ductwork in attic.

Energy saver dealers 204 202 views. Use metal flex or fiber board ducts that are insulated to code. 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. How to insulate the attic air sealing the attic energy saving attic insulation duration.

Use a pressure sensitive vapor retarder tape designed for ductwork. 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. If necessary switch the wires to reduce the blower to its lowest speed. 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. Cover the metal ductwork with closed cell spray foam. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. It was new when the ac was put in 7 years ago.

Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. 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. 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 attic ductwork is flex duct work.

The attic and walls are one of the most important areas to insulate in any space. Check the speed of the blower motor on the furnace. Tape any punctures in the insulation s vapor barrier to prevent leaks. I called out the original hvac company and they took a look and said they saw no water.

Mechanically fasten and mastic seal all duct connections. The foam provides a vapor barrier so the ductwork won t sweat. Cover the spray foam with fire retardant spray. If you want to cover metal ductwork with blown in insulation t hese steps must be followed in this order.

When it comes to insulation ductwork matters too. Most insulation relies upon the air space between its fibers to deliver the r value promised. Plan to pull up the flooring and layer new insulation on top of the old. That s what happened to the ducts in the lead photo of this article.

But what about the parts behind the walls and in the ceiling.