Insulating Attic Hvac Ducts

In this video this old house plumbing and heating expert richard trethewey helps a homeowner insulate his ductwork.

Insulating attic hvac ducts. If necessary switch the wires to reduce the blower to its lowest speed. Use metal flex or fiber board ducts that are insulated to code. Check the speed of the blower motor on the furnace. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords.

For an added layer of protection you can apply duct mastic to the tape and duct. Don t use standard cloth duct tape on hvac ductwork since the adhesive won t hold up to extreme temperatures. According to the u s. Department of energy attic insulation improvements combined with air sealing and proper hvac maintenance can cut your heating and cooling energy use by 20 to 50.

Read this before you start thinking about adding insulation to your attic. 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. The duct insulation should include a vapor barrier cover. When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value.

Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. 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.