In this case the temperature gradient between supply air and the ceiling can be such that the duct surface could be cooler than the local dew point.
Adding insulation to attic ductwork.
If it is less than an equivalent of r 30 you could probably benefit by adding more.
Add additional sealant if necessary.
Wrap the insulation around the duct and then pinch the seam closed.
In a vented attic this can happen when the duct is in close proximity to conditioned space i e the ceiling and also thermally isolated from the hot attic beneath the ceiling insulation.
Ted has more than a few cobwebs in his attic.
Test total duct leakage.
Insulation isn t only about keeping heat in.
Add weatherstripping around the perimeter and a sweep to the door of a walk up attic.
The problem with uninsulated ducts.
The cost and effort to add more insulation is minimal.
This isolates the attic from the rest of the home which means the attic isn t part of the conditioned envelope.
You need insulation even around your ducts no matter where you live.
When it comes to adding duct insulation your monthly savings in utility bills will soon cover the costs especially if you install the insulation yourself.
Use a zippered insulated tent to keep the enclosure draft free attic tent at 7 attic cover insulator 120.
If it s uninsulated you should insulated it to at least r 4 to r 8 for dfw.
To find out if you have enough attic insulation measure the thickness of the insulation.
I have a single level home with big open attic it has blown insulation and very narrow crawl space but my furnace electric has the single return air duct running about 4 feet from furnace it is in lowered ceiling from bathroom to kitchen my question is can i use a flexible hvac pipe duct an d run a network to living room and two bedrooms.
Repeat to insulate the remaining ducts.
Attic hatch or door.
The 1 800 square foot brick ranch in climate zone 4 dates from the 1960s but the previous owner installed both a furnace and ductwork in the attic just four years ago.
The unconditioned space also houses his hvac system.
To install preformed duct insulation start by disconnecting an elbow to expose the end of the duct.
Install loose fill insulation to cover the ducts and the attic floor to meet or exceed the code required r value for attic insulation.
Before insulating seal any air leaks and make roof and other necessary repairs.
If your rigid metal ductwork has any insulation it may already have enough.
Pull down stair or ladder.
The duct insulation should include a vapor barrier cover.
Secure the insulation with short strips of foil tape.
Consider adding more insulation as ductwork is farther from the furnace.
Apply a long strip of foil tape along the seam in the insulation.
In many homes the insulation layer in the attic is along the floor.
If you want to cover metal ductwork.