This is an especially relevant tip for flex ducts more on that in a minute but you need to make sure any ducts in your attic have proper support.
Attic duct return installation.
This pulls the air across your body.
If the supply ducts are in the floor then the return air should be located up high.
Return ducts in my attic.
Supply air from furnaces and air conditioners should be on outside walls.
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.
At least with the other one they had two inches of overlap.
Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords.
I ve read a bunch of articles here and on bsc s site concerning ducts in the attic.
Here the two liners weren t even touching.
Next areas to address are oversized supply box pentrations supply boxes that lift off the attic floor when supply grill is installed and return air leakage.
I have a couple questions.
Use metal flex or fiber board ducts that are insulated to code.
The flex duct liner inside wasn t connected.
If testing of ducts returns was code this would be a step in the right direction.
Improperly supported flex.
This allows the air to get into the return air duct.
As difficult to achieve as getting hvac companies to actually train their workers how to install ducts.
So that duct was sucking in attic air and sending it to the house.
The photo here shows one in a return duct.
The return air vent openings need to be on the opposite side of the room so the conditioned air is pulled across the room.
And this is just one of the reasons that the return ducts need to be installed directly across from the supply vents.
Install the square return air duct perpendicular to the joists.
Hard ducts without proper mooring will be unbalanced and unbalanced ductwork might be to blame for a number of hvac problems.
The ducts are installed strategically in these locations to help battle this heat loss or heat gain.
It comes down to three options the first of which is to convert his attic into a conditioned space by installing 4 1 2 inches of polyiso insulation above the roof deck and then adding a new standing seam metal roof.
You want to run it so it covers up all the holes you cut in the panning.
When installed in this fashion it will allow the system to suck the air throughout the entire room.
He d add open cell foam below the roof deck to give the assembly the required r value but the bids range from 40 000 to 60 000.
The tape on the duct liner wasn t sealed.
The duct insulation should include a vapor barrier cover.
Give your ducts the proper support.