Insulating Heating Ducts In Attic

Typical ducts install between a plenum or large supply duct and.

Insulating heating ducts in attic.

So logically the ducts deserve more not less 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. Inspect the span of ductwork to be insulated. All the ducts are in the attic.

For an added layer of protection you can apply duct mastic to the tape and duct. Other times insulation may be on the outside. Because the simplest and cheapest way to insulate an attic is to add material to the floor. Duct board much like the duct liner is also a fiberglass product.

When insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value. Looking at the cooling side only the additional load would be. Use a paintbrush to apply duct mastic to the joints where an elbow. 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. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. Insulating exposed heating ducts in attics basements and under subfloors can improve the energy efficiency of a heating system. Check the speed of the blower motor on the furnace.

After all most new homes have r 49 insulation on the attic floor holladay continues. The duct insulation should include a vapor barrier cover. Sometimes the insulation is inside the ductwork. If necessary switch the wires to reduce the blower to its lowest.

Use metal flex or fiber board ducts that are insulated to code. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. The existing metal ductwork in an older home may or may not have insulation. Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards.

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

R 8 duct insulation 5 227 btu hour. Look for signs of air leaks at seams or joints such as streams of dust. 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. Plan to pull up the flooring and layer new insulation on top of the old.