Insulate Heating Ducts In 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.

Insulate heating ducts in attic.

In this video this old house plumbing and heating expert richard trethewey helps a homeowner insulate his ductwork. Don t use standard cloth duct tape on hvac ductwork since the adhesive won t hold up to extreme temperatures. Other times insulation may be on the outside. Insulation typically works by preventing conductive heat flow and r value measures how effective it is at this.

Duct board much like the duct liner is also a fiberglass product. For an added layer of protection you can apply duct mastic to the tape and 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. Sometimes the insulation is inside the ductwork.

The existing metal ductwork in an older home may or may not have insulation. Hvac ducts should be buried under insulation hard covered too. Check the speed of the blower motor on the furnace. What is an attic insulation s r value.

All the ducts are in the attic. Putting a furnace in an attic is not ideal but will happen. Looking at the cooling side only the additional load would be. 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.

Let s look for constantly improving methods through sharing. 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. When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value.

R 8 duct insulation 5 227 btu hour. The r actually stands for resistance of heat flow that is. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. R value is a rating system used for insulation that measures its degree of insulating power.

Use metal flex or fiber board ducts that are insulated to code. Duct liner isn t generally a diy installation and if your ducts already have liner you don t need to insulate the exterior. Plan to pull up the flooring and layer new insulation on top of the old. 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.

Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. The duct insulation should include a vapor barrier cover.