Insulate Heating Ducts In Attic

Because the moving air is in the ductwork for only a short period of time it does not need the insulation r value the attic floor requires.

Insulate heating ducts in attic.

What is an attic insulation s r value. Plan to pull up the flooring and layer new insulation on top of the old. Other times insulation may be on the outside. All the ducts are in the attic.

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. Looking at the cooling side only the additional load would be. R 8 duct insulation 5 227 btu hour. For an added layer of protection you can apply duct mastic to the tape and duct.

Because the simplest and cheapest way to insulate an attic is to add material to the floor. R value is a rating system used for insulation that measures its degree of insulating power. When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. According to rightsuite the software we use the supply ducts have about 560 square feet of surface area and the return ducts 101 square feet.

Don t use standard cloth duct tape on hvac ductwork since the adhesive won t hold up to extreme temperatures. When hvac ducts are installed in a vented attic in a dry climate bury the ducts in attic insulation to protect them from temperature extremes in the unconditioned attic space. The duct insulation should include a vapor barrier cover. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place.

Putting a furnace in an attic is not ideal but will happen. Hvac ducts should be buried under insulation hard covered too. The existing metal ductwork in an older home may or may not have insulation. Insulation typically works by preventing conductive heat flow and r value measures how effective it is at this.

In this video this old house plumbing and heating expert richard trethewey helps a homeowner insulate his ductwork. Use metal flex or fiber board ducts that are insulated to code. Sometimes the insulation is inside the ductwork. If necessary switch the wires to reduce the blower to its lowest speed.

Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. Duct liner isn t generally a diy installation and if your ducts already have liner you don t need to insulate the exterior. The r actually stands for resistance of heat flow that is. Duct board much like the duct liner is also a fiberglass product.

Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. 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.