This past week we had our first overnight experience in the Sprinter. All seven of us plus the dog slept in the Sprinter. It was an OK sleep, but for 4 mornings straight, the windows and any exposed inside metal was drenched in condensation, I dried it off and let the Sprinter air out. Any issue with all this condensation on the inside? I left the Sunroof open on the last 2 nights…helped a little…but not a whole lot. Has anyone else experienced this issue and what have you done to prevent? Thanks.
I have experienced this, ran some tests, and asked people in the forum. I'm still working on a definitive solution. Here's what I have found so far:
- I got condensation behind panels, behind curtains, near the van's rear door openings, and even inside the tail light lenses. It dripped from above the side windows when I moved the van.
- I used a room dehumidifier in a closed van and it did no good. Only a little bit of water collected in the humidifer and much collected in the van - the van's cold surfaces worked much better as a dehumidifier.
- Some people who have interior Espar heaters reported that when they open their roof vents, they don't get condensation.
- A test where I idled the van all night with the heater and AC on and the fan on low drawing in outside air resulted in no condensation. It was very cold but the outdoor humidity may have been low.
I think the key is to keep forcing fresh air into the van to push out air that has collected moisture. I am wary about creating moisture barriers because of posts where others have said that a breach or slow absorption can lead to moisture collection. Since there are many places where you can't insulate or place a barrier, I
think that moisture elimination is the only way out, and hope it is possible.
My next test (after I install a CO and fire detector) is to run only the heater and the fan on low while idling all night when it is very cold and wet. If no condensation is found, then the next step will be to implement the "heater booster switch" mod found elsewhere in the forum, with changes to support a thermostat and run off a battery bank, so I don't have to keep the engine on. If that works, I'll try putting an Espar in the back. I'm not ready to do that yet, though, since I don't have the final placement of other stuff in the van.
Others with an Espar in the back have reported no condensation if they open their vents. You might want to get a confirmation on that, and see if the Espar is sucking fresh air in from outside. If that's something you're ready to do, it might work for you.
With seven people in your van, you may have to take more drastic measures (more air flow, more heat, etc.)
Insulate with wool and you'll never ever get condensation ever.
) produce a lot of water overnight.
