My house has a working AC compressor and certain rooms in the house get cold.
The problem is that 2 bedrooms in one section of the house have no air at all coming from the vents and never have since I've lived here. The problem is the duct work above the ceiling of the attic bedroom.
When I first went up there I found that while hardly any air is coming through the duct, the channel of wood beams between the roof and the ceiling had tons of cold air pumping through it and basically cooling the attic. I tried shoving as much spare insulation as i could find into every crevice around where the duct comes out of that channel. Now I've found that on the opposite side of the channel, the air is coming back out into the other side of the attic. I had an idea of using expandable foam to plug up the entire channel around the duct work. Maybe use expandable foam on both sides of the channel that the duct work passes through.
If that doesn't work, Then I fear the duct work will need to be replaced. Is there any way of doing this without ripping apart the ceiling in the bedroom. The attic bedroom takes up almost the whole attic with the ceiling composed of both side of the roof. Can any flex-duct be shoved up and over the top of the attic and somehow be pulled down the other side of the channel?
Sounds like the duct come apart
I have replaced ducts like that before
If the regesters are 10x6,12x6 or 14x6 you can get up to an 8" duct through it
First thing is to get the old crap out of the way, a rail/flang boot will be a pain since 1" all around the boot is between sheetrock and a boot rail.
Once you have a clear shot push 3/4 pvc to the reg.
Push the inside liner in to where you only have the outside liner, BTW USE good flex that has threads running through it, it will hold up better if you hit a snag.
Use good duct tape and be liberil with it because you want it done right the first time.
One person will have to push the flex into the reg hole while another pulls the pvc
If its easyer to pull the flex the other way then pull it that way.
Once that is done hook it up to your boot, mount the boot and hook up the duct to the supply duct.