Forum Discussion

crcr's avatar
crcr
Explorer
Oct 01, 2020

Need Help Understanding AC Vent Cover!



I was tightening screws and reattaching my main TT AC vent cover, and have some questions. Besides this large main vent, this unit does have five small round vents throughout the 28 ft TT

Below is an image of the inside of the vent cover. The top black section (a thin washable filter) covers the cold AC supply to the room.

The bottom section of the vent cover, covers the return air portion of the unit in the ceiling. However, as you can see in the pic, there is a piece of galvanized sheet metal covering that area, plus a rubber gasket under that sheet metal, the same size as the sheet metal. I am the second owner of this TT, but the piece of sheet metal and the rubber underneath it, very much seem to be factory and not something that the first owner added.

Without the cover on, both the air supply and the air return move a pretty good volume of air. With the vent cover on, due to the configuration of the vent cover, I don't get near as much air movement as without the cover on.

Questions:

Why does that galvanized tin plus full size rubber gasket cover the return side? What is the purpose of it?

In the pic you can see the slot vents along the perimeter of the vent cover. It would appear that they are for the return air, since they surround that side. Is that correct? And should they be open or closed? Opening them seems to perhaps increase the air flow a little bit.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Oct 03, 2020
    wa8yxm wrote:
    THe explanation: The A/C is in 3 parts
    The upper part is the "Works" (Compressor, Evap. Condenser and all the stuff that goes with them This is where the "Magic" happens (Air gets chilled, or heated depending on which side (in or out) you are on)

    THe Middle part, in some RV's is just a tunnel from inside to outside. In your case it's the "Ducting adapter" (Where the duct work to those 5 vents connects)

    Now the bottom part.. there are two versions of this. one is for "non-ducted" and it vents straight back down,, and LOUD I might add
    Yours has that vent blocked off to force the cold air into the ducts and out the remote vents (much less noisy by the way)

    The reason they did it that way is inventory reduction.> ONE ceiling panel works both with Ducted and Non-Ducted. just by adding or deleting the block off plate.


    Actually....
    The openings in ceiling grille have sliding louvers that when closed cold air is directed to ducts AND when OPEN they dump cold air direct into the common area to help quickly cool it.
    Hence the Name...CHILL GRILLE
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Oct 02, 2020
    THe explanation: The A/C is in 3 parts
    The upper part is the "Works" (Compressor, Evap. Condenser and all the stuff that goes with them This is where the "Magic" happens (Air gets chilled, or heated depending on which side (in or out) you are on)

    THe Middle part, in some RV's is just a tunnel from inside to outside. In your case it's the "Ducting adapter" (Where the duct work to those 5 vents connects)

    Now the bottom part.. there are two versions of this. one is for "non-ducted" and it vents straight back down,, and LOUD I might add
    Yours has that vent blocked off to force the cold air into the ducts and out the remote vents (much less noisy by the way)

    The reason they did it that way is inventory reduction.> ONE ceiling panel works both with Ducted and Non-Ducted. just by adding or deleting the block off plate.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Oct 01, 2020
    crcr wrote:
    OK, got it. Obviously my grille was installed 180 degrees off, so I will correct that. Thanks so much to both of you who responded, and so promptly! Much appreciated!

    Re the size of the pic -- yes, I know it was much too large. RV.net doesn't have a preview option before you host, so sometimes you don't realize the problem until you have already posted.

    The free hosting site that I used to use, wouldn't work anymore for some reason, and I had problems with every other image hosting site that I tried, and I tried a fair number. Any suggestions for a good free image hosting site that doesn't require sign up would be much appreciated!

    Thanks again, All!


    There is a 'Preview' Icon just to left of 'Spell Check' (ABC ck mark Icon) ***which doesn't work and hasn't since I joined
  • fj12ryder's avatar
    fj12ryder
    Explorer III
    Oct 01, 2020
    My thought would be if the cold air supply to the room was fully open you would get little to no flow of air to the other vents. If you want more air flow to the vents, you can close the side vents on the plastic cover.
  • crcr's avatar
    crcr
    Explorer
    Oct 01, 2020
    OK, got it. Obviously my grille was installed 180 degrees off, so I will correct that. Thanks so much to both of you who responded, and so promptly! Much appreciated!

    Re the size of the pic -- yes, I know it was much too large. RV.net doesn't have a preview option before you host, so sometimes you don't realize the problem until you have already posted.

    The free hosting site that I used to use, wouldn't work anymore for some reason, and I had problems with every other image hosting site that I tried, and I tried a fair number. Any suggestions for a good free image hosting site that doesn't require sign up would be much appreciated!

    Thanks again, All!
  • Dutch_12078's avatar
    Dutch_12078
    Explorer II
    Oct 01, 2020


    The side with the foam filter is the air return. The galvanized blanking plate is there to force more cold air through the ducting to the small round vents for more uniform cooling.
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Oct 01, 2020
    Picture is WAY too LARGE to fully see w/o scrolling back/forth up/down

    From your description the 'chill grille' was installed backwards
    Foam filter goes over the return side (open area where you can see evap coil)
    Galvanized section with gasket goes over room discharge are (area where you can see fan blower wheel)

    Slots....closed so air flows thru ducts
    Slots....opened to direct cold air downward directly into area below ceiling grille

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,198 PostsLatest Activity: Feb 12, 2025