AC duct

[Jud]

I’m losing ac air out of my duct work in the ceiling is there any way to seal the joints where they connect to each other?

[TitanMike]

I found cold air from a/c pouring out of an aluminum roof beam where the installer cut through it to install refrigerator vent on the roof.

I stuffed with some material I had at hand and no more leak.

[Jud]

Ok thank you! I was putting a second ac in the bedroom and when I pulled the skylight out I could fill cold air blowing out from between the roof and ceiling.I just fill like I’m losing all my air out of the joints where it is put together

[TitanMike]

Originally Posted by Jud

Ok thank you! I was putting a second ac in the bedroom and when I pulled the skylight out I could fill cold air blowing out from between the roof and ceiling.I just fill like I’m losing all my air out of the joints where it is put together

The roof assembly has a grid of channels molded in it where wires are run and air is ducted. Where holes are cut in roof it exposes this grid. Vents usually close off this "plenum" so the only time you will notice cold air loss is when the vent or skylight is removed. Rest of the time the cold air is forced through the channels where it exits at the registers.

Exception is when an opening is created in the roof with no sealing of the openjng sides.

[5picker]

Originally Posted by TitanMike

The roof assembly has a grid of channels molded in it where wires are run and air is ducted. Where holes are cut in roof it exposes this grid. Vents usually close off this "plenum" so the only time you will notice cold air loss is when the vent or skylight is removed. Rest of the time the cold air is forced through the channels where it exits at the registers.

Exception is when an opening is created in the roof with no sealing of the openjng sides.

X2

Depending on R/V model and construction, these ducts are simply channels cut into the Styrofoam as the roof section is molded together. There isn't really separate ducting with "joints".

Some stick & tin models do have tin ducts.

Since you didn't post your make/model, nor is it in your profile, we don't know what construction you have.

The air follows these ducts as long as everything near and along these channels is sealed. If you remove a vent or trim molding around a light, air may very well blow out the Styrofoam channels.

[MR.M]

my unit has fiber board duct work separate from other components in the ceiling . the space between roof and inside ceiling is about 8 " on my xlr . not enough insulation in the ceiling cavity though and wish i could add more .