Insulating Heating Ducts In Attic

Insulating exposed heating ducts in attics basements and under subfloors can improve the energy efficiency of a heating system.

Insulating heating ducts in attic.

So logically the ducts deserve more not less insulation. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. When the attic is 20 f that insulation is addressing a delta t of 50 f. The existing metal ductwork in an older home may or may not have insulation.

Use a paintbrush to apply duct mastic to the joints where an elbow. Use metal flex or fiber board ducts that are insulated to code. When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. Look for signs of air leaks at seams or joints such as streams of dust.

For an added layer of protection you can apply duct mastic to the tape and duct. Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards. But the air in the ducts is facing a delta t of maybe 100 f or 120 f a greater delta t. 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.

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. How to insulate your central air heating ducts 1. Duct liner isn t generally a diy installation and if your ducts already have liner you don t need to insulate the exterior. Inspect the span of ductwork to be insulated.

Looking at the cooling side only the additional load would be. All the ducts are in the attic. Don t use standard cloth duct tape on hvac ductwork since the adhesive won t hold up to extreme temperatures. Typical ducts install between a plenum or large supply duct and.

Sometimes the insulation is inside the ductwork. Plan to pull up the flooring and layer new insulation on top of the old. 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. Other times insulation may be on the outside.

Check the speed of the blower motor on the furnace. Duct board much like the duct liner is also a fiberglass product. 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. 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. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. After all most new homes have r 49 insulation on the attic floor holladay continues. R 8 duct insulation 5 227 btu hour.