Enclosed trailer build/condensation

Hunter26

Lil-Rokslider
Joined
Dec 28, 2017
Messages
136
So I have seen a few post on here about enclosed trailer builds and have seen condensation come up as an issue. Here is what I am wanting to do and would appreciate any advice. Most of the info I am adding is just an FYI in case it changes the advice.

I bought a 7x16 double axle trailer and will put some bunks in it. I will have to do more research into an electrical system set up but I do plan to run some lights and plug in electronics. Down the road I could put in an AC unit. I have a 2000 watt generator I was hoping to use for winter camping and want to be able to plug it in at any RV site. I plan to take the inside walls and ceiling down to studs and insulate with some foam board and spray in foam for gaps. I still got to figure out what if how to insulate the floor.

Question, how to control condensation as I was planning to run my generator and use a little electric heater/fan. I assume that is a pretty dry heat? Could I also plug in a dehumidifier at the same time? I assume I would need to vent it out of the trailer. Anybody know anything about it? I have heard of the little diesel heaters, RV furnace and propane heaters. Any of these options better than others and pro's and con's. I believe it is the moisture inside the walls is what really gives you issues and not in the open interior space? However I assume if you have it in the interior space you have it in the walls. What I like about the electric heater is all I have to do is plug it into my generator and it runs and has a thermostat. Super easy and quick.

I want to do this right but that said I don't want to go over board. I would imagine I will have it in cold weather maybe a total of two weeks a year at most. I also don't need a sauna but want to make it comfortable.

Thanks
 
Joined
Sep 24, 2019
Messages
1,104
Before I insulated the ceiling in mine, the condensation was terrible. It would leak from the ceiling just by breathing inside, and was obviously much worse with propane heaters. I installed 1” foam board and radiant barrier across the ceiling supports to reduce thermal bridging. I also installed a Maxxfan for the roof. This pretty much eliminated all condensation. I either use a buddy heater or a milkhouse heater and don’t have condensation issues anymore.
 
OP
Hunter26

Hunter26

Lil-Rokslider
Joined
Dec 28, 2017
Messages
136
Thanks guys.

Yeah, I think I almost learned that lesson with a wall tent which is kind of crazy to think.
 
Joined
Nov 14, 2020
Messages
1,206
The roof vent is crucial. You probably exhale a pint of water in your sleep every night. I’ve noticed in my little trailer if I don’t open the vent, The ceiling is wet in the morning even though it’s insulated. If I open the vent, everything stays nice and dry. My vent is not powered. It’s just a crank up.
 

*zap*

WKR
Joined
Dec 20, 2018
Messages
7,773
Location
N/E Kansas
a good battery fan like milwaukee m-18 (or 2) can help alot and you can turn the generator off while you sleep. ventilation is also key.
 
Joined
Jul 25, 2018
Messages
10
Location
Ak
I have a similar set up in my enclosed snow machine trailer, with a espar diesel heater. Those knock of Chinese heaters are pretty hard to bet for the price. Rather then a roof vent in my trailer and went with two off setting slider windows in my trailer. Works pretty good, nice cross ventilation and i don't have to worry about a roof leak from a roof vent.
 

jdinville3

Lil-Rokslider
Joined
Jul 6, 2019
Messages
137
I use an insulated Eskimo ice fishing tent with a Chinese diesel heater. Nowhere near as insulated as your trailer will likely be, but zero condensation issues with the setup. Heater sits outside the tent with a heater line coming in, absolutely an excellent way to dry boots and clothes out at the end of the day.
 
Joined
Aug 9, 2017
Messages
1,014
Location
Montana
Espar and Webasto are trusted diesel heaters used on boats and rvs. They also make gasoline versions to maintain one fuel source.
Propane is easiest for trailer applications. Direct vent to exterior.
Glue blue foam board insulation to underside of trailer with PL300. Use same thickness as angle iron frame. Attach sheet metal to enclose insulation.
 
Joined
Jun 15, 2017
Messages
2,502
Location
San Antonio
I think this goes without saying, but I’ll say it anyway. Make sure you have plenty of airflow with heaters. Too many people have never woken up…
...and a carbon monoxide detector on top. Few years ago three generations got wiped out down here in an enclosed trailer. Grandpa, father, and son. Scares the daylights out of me every time I see one now.

You could probably install an RV style hydroelectric heater.
 

packer58

WKR
Joined
May 28, 2013
Messages
1,002
Iv'e built two enclosed trailer conversions and yes, condensation is a major issue. Any fuel type heat source that doesn't vent to the outside will create condensation, and just you being in there will create condensation. The other thing is to create a thermal break between the cold exterior and the warm interior via insulation, even at that without a dry heat source you will get condensation on most of your screw heads and metal surfaces.

I installed a 30,000 BTU RV furnace in my current build and it is an absolute game changer controlling condensation in my trailer, unless i'm boiling water for cooking there is NO condensation other than maybe a touch directly over the stove top.

Trailer is a 8.5X16 V nose and that heater will run you out if your not careful. Had negative temps while coyote hunting last winter and had no issues staying warm.

PM me if you like and I can send a ton of pics.
 
Joined
Jan 16, 2018
Messages
1,037
We insulated our roof with spray foam, we have the two standard side vents and a roof vent as well. We use a Big mr. Buddy heater that has a fan on it. It seems like if there's any breeze outside we are getting enough air movement to minimize condensation.

Always, ALWAYS have a carbon monoxide detector in your trailer if not running electric! We have one mounted on the higher and one down lower just for insurance. Can't be too careful!
 

rayporter

WKR
Joined
Jul 3, 2014
Messages
4,420
Location
arkansas or ohio
Iv'e built two enclosed trailer conversions and yes, condensation is a major issue. Any fuel type heat source that doesn't vent to the outside will create condensation, and just you being in there will create condensation. The other thing is to create a thermal break between the cold exterior and the warm interior via insulation, even at that without a dry heat source you will get condensation on most of your screw heads and metal surfaces.

pay attention to experience!
 

Weldor

WKR
Joined
Apr 20, 2022
Messages
1,937
Location
z
Mcmaster-carr is a great source for any type of vent you need. I put 4 sidewall vents in .works good and they are small enough you can adjust for weather.
 

Beendare

WKR
Joined
May 6, 2014
Messages
9,101
Location
Corripe cervisiam
I’m in the same boat, Modding an enclosed trailer. Insulation, CO2 monitor and a good Maxair vent for sure.

I’m going solar and Lithium battery so I don’t have to hear a genny- I hate those.

Electric heater or AC takes too much juice. Propane heaters give off a lot of condensation. The best option for me is the little diesel heaters.
 
OP
Hunter26

Hunter26

Lil-Rokslider
Joined
Dec 28, 2017
Messages
136
Thanks for all the feedback. I am curious exactly how people have “set up a thermal break”? Sounds like something that would be worth it. Point taken in the co2 detector. I will be sure to have a couple just to be safe.
 
Top