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.

The existing metal ductwork in an older home may or may not have insulation. 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. When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. What is an attic insulation s r value.

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. Duct board much like the duct liner is also a fiberglass product. 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. Let s look for constantly improving methods through sharing.

Other times insulation may be on the outside. Duct liner isn t generally a diy installation and if your ducts already have liner you don t need to insulate the exterior. Because the simplest and cheapest way to insulate an attic is to add material to the floor. The duct insulation should include a vapor barrier cover.

Use metal flex or fiber board ducts that are insulated to code. Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards that specify an r value of 8 for attic ducts and 6 for ducts located anywhere else. Sometimes the insulation is inside the ductwork. Plan to pull up the flooring and layer new insulation on top of the old.

Hvac ducts should be buried under insulation hard covered too. For an added layer of protection you can apply duct mastic to the tape and duct. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. Looking at the cooling side only the additional load would be.

R value is a rating system used for insulation that measures its degree of insulating power. All the ducts are in the attic. R 8 duct insulation 5 227 btu hour. Insulation typically works by preventing conductive heat flow and r value measures how effective it is at this.

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. 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.

Check the speed of the blower motor on the furnace. If necessary switch the wires to reduce the blower to its lowest speed.