How To Insulate Duct Work In Attic

Look for signs of air leaks at seams or joints such as streams of dust.

How to insulate duct work in attic.

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. Mechanically fasten and mastic seal all duct connections. How to insulate the attic air sealing the attic energy saving attic insulation duration.

It was new when the ac was put in 7 years ago. Use a pressure sensitive vapor retarder tape designed for ductwork. The duct work is the backbone of air exchange and ventilation. 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.

Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. Avoid compressing the insulation. How to insulate your attic duct system step by step with video instructions assess current state of attic insulation. Use metal flex or fiber board ducts that are insulated to code.

Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. Sure up leaky duct joints. Cover the metal ductwork with closed cell spray foam. Use a paintbrush to apply duct mastic to the joints where an elbow.

Insulation itself keeps warm air in and prevents cold air from infiltrating. Make sure the foil surface of the insulation is free of dust before applying the tape. How to insulate your central air heating ducts 1. If necessary switch the wires to reduce the blower to its lowest.

When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. Most insulation relies upon the air space between its fibers to deliver the r value promised. 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. Cover the spray foam with fire retardant spray.

Tape any punctures in the insulation s vapor barrier to prevent leaks. The duct insulation should include a vapor barrier cover. Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards. Inspect the span of ductwork to be insulated.

I called out the original hvac company and they took a look and said they saw no water. The foam provides a vapor barrier so the ductwork won t sweat. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place.