Hello i have a difficult situation.
Insulate plenum attic.
Describing the general internal insulation technique to stop your ac unit from sweating on the outside.
The plenum is about 7 feet long x 2 feet wide x 1 foot high.
Then you ve got r318 4 to consider.
Try r316 3 r316 4 r316 5 4 you might claim an exemption under r316 5 4 1 and 2 but could really piss an inspector off.
After ripping everything out in the house and basement now the trunk is.
Affix rigid foam insulation to the attic side of the hatch or door.
6 8 insulated fleixible duct lines come off of the plenum.
Insulating exposed heating ducts in attics basements and under subfloors can improve the energy efficiency of a heating system.
This isa recently installed system performing well indoor humidity steady at 45.
I don t see any mold or mildew on the joists the floor insulation is dry and there is no condensation anywhere except the supply plenum covered in condensation soaked on bottom and to lesser extent the return plenum.
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.
Attic hatch or door.
Getting a new complete system inside and out.
Mine is an 80 furnace 92 ac.
Typical ducts install between a plenum or large supply duct and.
I had to completely gut the existing hvac system in my 1991 house due to numerous major issues flex tubing like swiss cheese facing into the plenum kinks leaks a branch off the end of the trunk returns in the wrong place missing registers in some rooms too many in others etc.
Use a zippered insulated tent to keep the enclosure draft free attic tent at 7 attic cover insulator 120.
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.
Two other companies both use internally insulated and claim they are the way to go.
Especially applicable in humid southern climates.
My crawl space is averaging 72 humidity right now raleigh nc.
Should you always insulate the plenum on an attic furnace ac horizontal setup.
Insulating the plenum on a forced air system.
One company is touting externally wrapped insulation for the metal plenums as their key value proposition over internally insulated metal plenums.
