Possibly a dumb question? 2016 Sundance 3700RLB

All, I noticed in the ceiling of my unit. their are multiple 5/7" diameter vent looking rings.?
What are they for? My Ac units dump and return so they are not Ac vents... my heater is on the floor. So this leaves me scratching my head.
is it possible they are Heater vents? and their is a heater line running up some inside space?
OR are they just vents for the ceiling/roof space?
Thanks
Sam

I have 13 of these in my Bighorns' ceiling. 7 blow cold air (doorside) and 6 suck the air back (off doorside).

When I removed them I found 5 (of the 6) return vents had a (dirty) filter installed within them.
Still working with my dealer to get the proper (missing) sixth filtered one.

Your AC "dump" grate should be able close and make the air come out the ducts.

NP_Chief said:

Your AC "dump" grate should be able close and make the air come out the ducts.

Click to expand...

Spot on...
When I was cleaning the return I thought hey let me open the grate. (perhaps a dual purpose grate 1: direct flow. 2: feed the ceiling duct work.)
I figured closing it was a bad idea less air flow. At the time I also did not notice the ports feeding the ceiling duct.

Thanks for this!
-Sam