In addition to making the unit hard to get to for service high attic heat can trigger the.
Insulating hvac ducts in attic.
Most attic ducts are insulated flex ducts that is flex ducts with r 6 or r 8 fiberglass insulation along with an exterior polyethylene jacket.
Duct liner isn t generally a diy installation and if your ducts already have liner you don t need to insulate the exterior.
Duct board much like the duct liner is also a fiberglass product.
Duct insulation keeps air that s supposed to be cool cool and air that s supposed to be warm warm.
Secure the insulation with short strips of foil tape.
When the attic is 20 f that insulation is addressing a delta t of 50 f.
Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards that specify an r value of 8.
Looking at the cooling side only the additional load would be.
So logically the ducts deserve more not less insulation.
All the ducts are in the attic.
The duct insulation should include a vapor barrier cover.
To install preformed duct insulation start by disconnecting an elbow to expose the end of the duct.
Insulated ducts have been the standard for decades now.
Obviously it s hard to install r 60 duct insulation.
Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords.
Put it in an attic full of blown insulation and you re forcing it to work harder to vent its heat.
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.
Use metal flex or fiber board ducts that are insulated to code.
Insulating hvac ductwork when insulating hvac ductwork use a foil faced fiberglass insulation with an r 6 or higher r value.
But the air in the ducts is facing a delta t of maybe 100 f or 120 f a greater delta t.
How to insulate your central air heating ducts.
Repeat to insulate the remaining ducts.
Apply a long strip of foil tape along the seam in the insulation.
Look for signs of air leaks at seams or joints such.
R 8 duct insulation 5 227 btu hour.
Make sure the foil surface of the insulation is free of dust before applying the tape.
No building inspector worth his or her salt is going to let any builder or hvac contractor get away with installing ducts that aren t insulated.
Inspect the span of ductwork to be insulated.
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.
Snap a plastic cap onto the duct end then slip the preformed insulation over the duct.
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.
