AC Unit Roof Seal

[jeffdawgfan]

This is a topic/question not really specific to a particular model but applicable none the least. I was on top of TT cleaning rubber roof and applying protectant. I pulled the shroud off our AC unit to clean around unit and found that there is not any caulking around the AC unit. Instead there is a dense rubber foam that I presume is for preventing condensation while the unit is running. I gently looked under the foam an found the rubber roof appears to be tucked down into a sheet metal liner the AC unit sits in.

Wondering if this is by design to allow easy removal of AC unit for repairs/maintenance or a missed caulking area from factory. HAs anyone else looked at what kind of seal/caulking is around their AC unit? My first inclination is to caulk the joint all the way around but that would make removing unit for maintenance a PIA. As the AC unit is the most likely item to need repairs on the roof I wonder if this is a design thing and any moisture that gets past the rubber foam is simply directed into the condensation line for the AC unit.

[wrvond]

The gasket is neoprene, and does not require additional sealant. You can inspect it for damage and replace if necessary (a real pain due to wiring, etc. ). It is best to look at it from inside the camper to ensure it is evenly compressed to about 1/2" thickness. The four mounting bolts should be torqued to 40-50 inch pounds.
The roof is curved, so water should not puddle around the unit during operation.

[TURBS]

Only seal needed is the foam gasket you seen.

The gasket when torqued properly should be roughly 1/2" thick.

This is what it looks like with a/c removed.


There is sealant there only because a vent was removed prior to installing the a/c.

The sealant was 90% removed before a/c install.

Torque on the a/c mounting bolts can be checked . 40 to 50 inch lbs.



2008 2500hd Duramax
2015 Columbus 320RS
2016 nights camped "0"
2015 nights camped "34"

[jeffdawgfan]

Thanks for pic and info. That puts my mind more at ease.

[hikerjohn7]

Originally Posted by wrvond

The gasket is neoprene, and does not require additional sealant. You can inspect it for damage and replace if necessary (a real pain due to wiring, etc. ). It is best to look at it from inside the camper to ensure it is evenly compressed to about 1/2" thickness. The four mounting bolts should be torqued to 40-50 inch pounds.
The roof is curved, so water should not puddle around the unit during operation.

Where could I find a diagram of a typical RV AC mounting configuration? I would really like to better understand details on things like how the AC cold air circulation outflow port(s) couples with the ceiling air ducts. I suspect that condensation from one of my AC's is getting into my RV ceiling but I can't figure out what the possible routs are.

[TURBS]

Every manufacture does it differently.

Normally they just hollow out the styrofoam as a duct.


2008 2500hd Duramax
2015 Columbus 320RS
2016 nights camped "0"
2015 nights camped "34"

[floridela]

Originally Posted by wrvond

The gasket is neoprene, and does not require additional sealant. You can inspect it for damage and replace if necessary (a real pain due to wiring, etc. ). It is best to look at it from inside the camper to ensure it is evenly compressed to about 1/2" thickness. The four mounting bolts should be torqued to 40-50 inch pounds.
The roof is curved, so water should not puddle around the unit during operation.

Agree on everything, but just to remind the OP that things do loosen up as unit ages. It is a good idea to check the gasket occasionally, maybe every couple of years to make sure it is compressed and making a good seal. A friend of mine was off camping and was in a major deluge in Oregon. He had a big leak coming in and didn't realize that the gasket needed to be re-tightened. After we talked on the phone and I mentioned the gasket he went and checked and sure enough it was loose. Tightened it up and no more leak, but he was going to get a new gasket just to make sure there would be no further leaks from the a/c.