AC Condensation on ceiling

ODonnell

Member
We have a 2015 Bighorn 3260 and having problems with condensation building up on the ceiling inside the fifth wheel right below where the AC is located. Has anyone experienced this problem??
 

osims

bsims
I have noticed this when we first set up and it's hot in the trailer but soon as it cools off inside I don't notice any longer
 

Lynn1130

Well-known member
There should be a section in your owners manual concerning condensation. Because the trailer is closed, water from cooking, coffee/tea making and the human body cannot escape and build up on walls and ceilings. This will happen in warm or cold weather but is more common in cold weather. It is important to keep a window or vent open a few inches to help with this or you can end up with damage to the interior.
 

ODonnell

Member
We had the door open, and the condensation still built up. We have a Dometic AC and could not find any thing regarding condensation in the owners manual.
 

TandT

Founding Utah Chapter Leaders-Retired
I agree with the others, air circulation is the key. Crack a window or vent if it is humid inside the rig. If you are cooking always turn on a vent and open a window.

I have a shroud over my bathroom vent and I almost always leave it open. Trace
 

danemayer

Well-known member
We have a 2015 Bighorn 3260 and having problems with condensation building up on the ceiling inside the fifth wheel right below where the AC is located. Has anyone experienced this problem??

I saw this at a chapter rally 2 years ago. Terrible condensation on the ceiling. Turned out they had left a window open and all the humid air leaking in was causing the problem.
 

mobilcastle

Well-known member
Turn fan on high when it is real humid. Make sure the sensor is correctly place on the evaporator coils if you have a problem.
 

Lynn1130

Well-known member
I suppose that locations down south or on the east coast can be pretty humid outside but in most cases the humidity is higher inside than out. If it is 80% outside and you have water on things inside, you have reached 100% at some inside locations. A exhaust fan running on low will probably be better than an open window in those locations.
 

AAdams

Well-known member
Here in the Mid-west the humidity is high and we run the A/C all the time. We do not open windows and do not have the condensation problem. We use the exhaust fan in the bathroom to remove the humidity when we take a shower and the fan in the exhaust hood when we are cooking. Now when we had the RW, we would use a separate dehumidifier when needed. So far we haven't had to pull the dehumidifier out with the BH.
 
Have a 2014 Landmark. I guess we have what they consider "quiet" air condioners. No open vent under air conditioners, just round vents in ceiling (one side output, other side the return). In Iowa right now and after running air for several hours the rig smells musty. Sometimes we get condensation under the air conditioners. Any ideas?
 

Silverado23

Iowa Chapter Leaders
Have a 2014 Landmark. I guess we have what they consider "quiet" air condioners. No open vent under air conditioners, just round vents in ceiling (one side output, other side the return). In Iowa right now and after running air for several hours the rig smells musty. Sometimes we get condensation under the air conditioners. Any ideas?

You might want to check the pan under the evaporator coil to see if you have debris or a blockage preventing condensation from draining out of the pan. You could also need to clean the evaporator coils both could lead to issues of musty odors. Also be sure to clean your air filters (if present) on your AC unit they could be dusty and have mold growing on them. If the water is not draining from the evaporator pan it could be dripping onto the filter causing the musty odors.
 

jbeletti

Well-known member
We had the door open, and the condensation still built up. We have a Dometic AC and could not find any thing regarding condensation in the owners manual.

If your AC needs to be on to cool the coach "and" you have the RV door open, there is too much humidity getting in the coach and this will cause condensation on the ceiling at the coldest parts of the cooling system. Seen this many times at RV shows where we have to leave the doors open and it's so hot, we want the AC running.
 

Jimsryker

Well-known member
I awoke to this phenomeon this morning and had to search here to see what is up. We are down on the coast for our annual beach trip and last night it was just too muggy. I have yet to truely use the Dometic Brisk II A/C unit in the bedroom, so I turned it on. Paying for full hookups afterall...

When I got up, the entire plastic shroud of the AC unit was "crusted" in drops of water. The bed spread was not wet. The entire trailer was open. Screen door all the way back to the windows in our 2013 Cyclone 3010. Only the doors were closed. I verified that the water draining from the AC was working. It dripped down on the front R/H corner. Verified that early on and again in the morning so it wasn't draining into the chassis. After reading here, I have to think that it's just the humidity building up on a wide open trailer and it's very humid due to a tropical storm that is edging up from mexico. Wanted to add my two cents here in case it helps another adventurer.

Regards,

Jimbo
 

Sweenja1

Member
We had the same issue last month with condensation building on the ceiling below the air conditioner. We were running the bathroom ceiling fan which was suggested by somebody early on as a means to control humidity. I was doing some research to find out why it was doing this. I read that the air conditioner itself in a way acts as a dehumidifier. It said not to leave vents or windows open and to seal the RV and let the air conditioner do its job. I closed an open windows and vents and sure enough got rid of the problem. Now we either use the air condition or the power roof vents but not both.
 

hoefler

Well-known member
Also keep in mind, if you are using a vent/power vent, while you are exhausting air, humid make up air has to come in from somewhere.
 
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