Insulating Metal Ductwork In Attic

Although both the attic floor and the ductwork are insulated ted recognizes the situation isn t ideal.

Insulating metal ductwork in attic.

Effect of inadequate insulation on ductwork. The 1 800 square foot brick ranch in climate zone 4 dates from the 1960s but the previous owner installed both a furnace and ductwork in the attic just four years ago. You can cover metal ductwork with blown in insulation if you take two steps first. Proper duct insulation is a major key to ensuring your home s energy efficiency.

Table 1 shows effective r values for 8 inch round ducts at three attic insulation levels and three duct insulation levels r 4 2 r 6 and r 8. The effective r value of a buried duct installation depends on the size of the ducts the r value of the duct insulation and the depth of the loose fill insulation. For diy attic insulation you ve got two choices. When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value.

Metal flashing or scrap plywood to create a safety gap of at least 3 inches all around fixtures. Wires exhaust fans and ducts. Insulation works because it is very inefficient at transferring heat. Our heating and ac ducts are 100 within the thermal envelope in the floor trusses above our insulated basement.

Other times insulation may be on the outside. Sometimes metal ducts are lined with duct liner a 1 inch thick fiberglass board that insulates the interior of the duct rather than the exterior. Repeat to insulate the remaining ducts. Sometimes the insulation is inside the ductwork.

But our erv ducts stand alone system not tied in w heat pump and 2 jumper ducts for pressure balancing from bedrooms are suspended above the insulation in our vented attic. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. The existing metal ductwork in an older home may or may not have insulation. Youtube insulating attic ductwork.

Apply a long strip of foil tape along the seam in the insulation. Think about it if you touch the metal side of a frying pan on the stove you get burned right. The department of energy claims that the average us home loses hundreds of dollars a year in heating and cooling costs. Ted also has inherited a powered attic ventilator.

This is because metal is very good at transferring heat and also why it is a horrible insulator. Duct liner isn t generally a diy installation and if your ducts already have liner you don t need to insulate the exterior. To install preformed duct insulation start by disconnecting an elbow to expose the end of the duct. Secure the insulation with short strips of foil tape.

Loose fill or batt the common term for blanket insulation.