"2. Duct Work – Specifically check for collapsed duct work for your WARM air returns. All of my warm air returns were collapsed. I used two 9” pieces of 1.25” PVC on either side of each duct to open them up. Right off the bat there was a significant increase in the performance of the system. I checked my cold air supply duct work and found all to be OK. A bore scope helps.
Check all cut openings in the duct system – Both warm and cold air ducts at their cut opening points need re-tapped ensuring a positive seal. INTERIOR: For the cold air diffusers inside the 5ver this will ensure that cold air being pushed from the AC units flows fully into the trailer and not between the duct and the ceiling panels. For the warm air returns it will ensure that supply air back to the AC is pulled from the 5ver interior and not the cavity between the roof and the ceiling. Almost all interior cut openings in my case had to be re-tapped so I redid them all. The foil tape was either junk to start with or deteriorated enough over two years that all openings separated. EXTERIOR: Yep there are cuts on the roof to check. Get up on the roof and pull the covers off your AC units. Remove the plenums and you will see one hole for your warm air returns and the other hole will be for the cold air supply. You should see where the same tape was used to seal both openings to their respective ducts. In my case there were huge gaps where the openings, both front and rear locations, had separated. Once again allowing cold air into the roof/ceiling cavity and warm air to be pulled from the cavity. NOTE: Bring a vacuum to get all the wood chips from the factory picked up.
4. Cold Air Diffusers – Two things here. First trim the base/collar that inserts into the ceiling to ensure it doesn’t protrude into the duct restricting air flow. Second, optional, remove every other vent blade to allow increased air flow exiting the duct. Or just buy new diffusers that have a shorter collar length and are more open to better air flow. I’m CHEAP. If you take your time removing the blades/fins it looks good and works great."
So - I am a
complete newbie when it comes to 5ver's period. My 2016 Montana 3820FK. The A/C units (both of them) are severely troublesome. I have already contacted Dometic regarding the thermostats, thanks to the other posts.
The AC in the bedroom works fairly good, and keeps the temp, as long as the fan is set to High. It doesn't work at all at any other time.
The AC in the living room works (on HIGH fan), but it does not cool down like it should.
I have read that I should check the duct work, but I have absolutely no idea how to do this. I don't know which return goes where, etc.. I know where the vents are in the ceiling with the little pieces of foam.
Does anyone have any pictures or a blow by blow of how to check these?
Any help, ideas, hints, anything would be so much appreciated!
Vicky
17 year DoD - Support your Services!