Insulating Heating Ducts In Attic

Looking at the cooling side only the additional load would be.

Insulating heating ducts in attic.

Typical ducts install between a plenum or large supply duct and. Insulating exposed heating ducts in attics basements and under subfloors can improve the energy efficiency of a heating system. 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. When the attic is 20 f that insulation is addressing a delta t of 50 f.

But the air in the ducts is facing a delta t of maybe 100 f or 120 f a greater delta t. If necessary switch the wires to reduce the blower to its lowest. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. Look for signs of air leaks at seams or joints such as streams of dust.

R 8 duct insulation 5 227 btu hour. Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards. How to insulate your central air heating ducts 1. Plan to pull up the flooring and layer new insulation on top of the old.

The existing metal ductwork in an older home may or may not have insulation. When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. Don t use standard cloth duct tape on hvac ductwork since the adhesive won t hold up to extreme temperatures. Made from 1 to 2 inch thick sheets of rigid glass fiber and coated with an aluminum laminate for a moisture air barrier duct board comes in sections that fit together like metal ducts.

Press a continuous strip of foil tape to all longitudinal seams along straight runs of duct. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. All the ducts are in the attic. Duct board much like the duct liner is also a fiberglass product.

So logically the ducts deserve more not less insulation. Inspect the span of ductwork to be insulated. Other times insulation may be on the outside. 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.

For an added layer of protection you can apply duct mastic to the tape and duct. Check the speed of the blower motor on the furnace. 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. The duct insulation should include a vapor barrier cover.

Use a paintbrush to apply duct mastic to the joints where an elbow. Sometimes the insulation is inside the ductwork. 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. Because the simplest and cheapest way to insulate an attic is to add material to the floor.