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Old 02-21-2021, 03:18 PM   #1
Windermere Campers
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Air Flow Issues

I have 2017 3950BR. We live in Florida and camp all year. During the summer the a/c has a difficult time keeping up. Per forum recommendations I have tried removing a/c vent covers to let a/c flow better. Helps but still not great. I have seen a lot of posts about crushed ducts. I checked that today. Nothing seems crushed. I have read numerous strings that inserting a 1 1/2 inch pvc pipe may help. Several questions:

1. Should I insert the pvc pipe into the vent or the return or both?

2. I bought some 1 1/2 inch pvc pipe but it is thick and non-flexible so how long a piece do you recommend inserting? My a/c vent only has a 3-4” diameter hole and my return in rectangular about 12x4? I only ask because my 1 1/2 pipe will not bend so I am limited on the length of pipe.

3. Do you insert the pipe at the opening or try to push in far into the vent?

4. Most stores sell schedule 40 pvc pipe. Should I be using that or something thinner.

5. If inserting pipe doesn’t work any other suggestions? Thanks in advance.
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Old 02-21-2021, 04:39 PM   #2
Golfmedik
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Quote:
Originally Posted by Windermere Campers View Post
I have 2017 3950BR. We live in Florida and camp all year. During the summer the a/c has a difficult time keeping up. Per forum recommendations I have tried removing a/c vent covers to let a/c flow better. Helps but still not great. I have seen a lot of posts about crushed ducts. I checked that today. Nothing seems crushed. I have read numerous strings that inserting a 1 1/2 inch pvc pipe may help. Several questions:

1. Should I insert the pvc pipe into the vent or the return or both?

2. I bought some 1 1/2 inch pvc pipe but it is thick and non-flexible so how long a piece do you recommend inserting? My a/c vent only has a 3-4” diameter hole and my return in rectangular about 12x4? I only ask because my 1 1/2 pipe will not bend so I am limited on the length of pipe.

3. Do you insert the pipe at the opening or try to push in far into the vent?

4. Most stores sell schedule 40 pvc pipe. Should I be using that or something thinner.

5. If inserting pipe doesn’t work any other suggestions? Thanks in advance.
The vent "mod" required for the '16-'17 rigs is talking about putting 1 1/4" Inside diameter pipe in the return vents as the units could not breathe. The 1 1/4" has an outside diameter of 1 1/2" that equals what the duct size should be. Usually the opening size of the return vents are around 9" so I cut mine at 9" lengths and inserted them lengthwise to the rig and then turned them to point the direction of the airflow. That way the air flows through the pipes. I put one on either side of my ducting on one side but the other side was so severely crushed that I had to put three on that side as one went in the middle. Also, remember to do the front AC unit too! I then ordered JR Products vent covers/vents as they had larger openings for airflow, but you can always cut out every other directional vent on the cover to give you more flow.
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Old 02-21-2021, 08:48 PM   #3
DQDick
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One more thing I did was to cut down the fixture that holds the vent covers so that it matched the height of the ductwork. Before that they proturded into the ductwork blocking some flow.
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