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Old 06-10-2019, 06:40 PM   #53
mtlakejim
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Join Date: Oct 2017
Location: Bee Branch
Posts: 2,620
M.O.C. #20693
Quote:
Originally Posted by rsaylor3 View Post
I have a 2020 high country that we just bought. It seems the a/c tracks in the ceiling are rectangular and made of pretty hard foam. Do these collapse as you are speaking about? Or is this collapsing in older models with more traditional round ducting?
Its the newer rectangular returns on either side of your AC unit that collapse. The engineers came up with that idea to supposedly make the A/C units quiet (which it does to some degree). However the engineers failed to specify a material that would hold it's shape under the weight of the roof and negative pressure created by the unit. The return air ducts do in fact collapse and it is readily evident if you observe them with the covers off and the AC running. Only reason the discharge ducts don't collapse is the positive pressure of the air blowing thru them.

Its a classic example of an engineer addressing one issue and creating another! Two pieces of 1' 1/4" PVC cut just short of the length of the return air duct covers inserted into the duct parallel to the air flow equidistant from each other and the sidewalls will assist with keeping the airway open.

Cutting every other discharge vent cover vane with a box cutter will improve discharge airflow as well. Between the two mods you will see a major improvement. However you will still be challenged to maintain more than 20F difference from the outdoor temp. If you live or camp in an area where triple digits are common (like us in the SE NM desert) you WILL need a third A/C to keep the rig at a reasonable temp. We have too for the benefit of our two Chihuahuas! It is the primary reason we are still considering buying a house here while I finish my career.
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James & Irene Wilson
Bee Branch, AR.
2017 Ram 1 ton diesel duallyCrew Cab/Long Bed
2018 Montana High Country 381TH Garage Full of Toys
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