Insulating Metal Ductwork In Attic

If you want to cover metal ductwork with blown in insulation t hese steps must be followed in this order.

Insulating metal ductwork in attic. A metal duct conveying cool conditioned air through a broiling attic in summer or warm air through a chilly crawl. Energy saver dealers 204 202 views. Plan to pull up the flooring and layer new insulation on top of the old. If necessary switch the wires to reduce the blower to its lowest speed.

Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. Go to the basement or crawl space of your home. Summer hasn t even arrived he notes in a post at gba s q a forum and when the temperature outside climbs to more than 95 f the temperature in the attic tops 120 f.

Insulating hvac ductwork when insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. In this video this old house plumbing and heating expert richard trethewey helps a homeowner insulate his ductwork. Choose a faced fiberglass. Wear work gloves long sleeves and long.

Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. Make sure the foil surface of the insulation is free of dust before applying the tape. Made from 1 to 2 inch thick sheets of rigid glass fiber and coated with an aluminum laminate for a moisture air barrier duct board comes in sections that fit together like metal ducts. Consider adding more insulation as ductwork is farther from the furnace.

If it s uninsulated you should insulated it to at least r 4 to r 8 for dfw. Duct board much like the duct liner is also a fiberglass product. Protect yourself from itchy fibers when working with fiberglass insulation. Duct liner isn t generally a diy installation and if your ducts already have liner you don t need to insulate the exterior.

Wrap metal duct tape around any seams you see in the ducts. If your rigid metal ductwork has any insulation it may already have enough. Although both the attic floor and the ductwork are insulated ted recognizes the situation isn t ideal. Mechanically fasten and mastic seal all duct connections.

Acute temperatures in these areas contribute to thermal loss in metal ductwork. The duct insulation should include a vapor barrier cover. Check the speed of the blower motor on the furnace. Use metal flex or fiber board ducts that are insulated to code.

Because the simplest and cheapest way to insulate an attic is to add material to the floor. How to insulate sheet metal ac ducts 1.