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.

How to insulate ductwork in attic.

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. How to insulate the attic air sealing the attic energy saving attic insulation duration. Mechanically fasten and mastic seal all duct connections. Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct.

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. The attic ductwork is flex duct work. Because the simplest and cheapest way to insulate an attic is to add material to the floor.

Cover the spray foam with fire retardant spray. Plan to pull up the flooring and layer new insulation on top of the old. If you want to cover metal ductwork with blown in insulation t hese steps must be followed in this order. Tape any punctures in the insulation s vapor barrier to prevent leaks.

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. That s what happened to the ducts in the lead photo of this article. I called out the original hvac company and they took a look and said they saw no water. Cover the metal ductwork with closed cell spray foam.

The foam provides a vapor barrier so the ductwork won t sweat. Check the speed of the blower motor on the furnace. But what about the parts behind the walls and in the ceiling. If necessary switch the wires to reduce the blower to its lowest speed.

Avoid compressing the insulation. It was new when the ac was put in 7 years ago. Use a paintbrush to apply duct mastic to the joints where an elbow connects to a duct. Energy saver dealers 204 202 views.

Use metal flex or fiber board ducts that are insulated to code. Bury the ducts deeply in insulation. 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.

When it comes to insulation ductwork matters too.