Managing Moisture in a FWC

The hours spent scouring the inter-webs in the ways of advice to the new Four Wheel Camper owners seems to have paid off. Something we knew we’d have to combat, especially with the heat-box-Vizsla-mouth-breather inside, was condensation.

The first step, was ordering a camper with a roof vent and a power roof vent.

The other thing we got is a thermal pack. This, like the roof vents, is required equipment to keep things dry.

Next, we put Hypervent anti-condensation mats under our mattress. We actually cut it to fit the collapsed width. That makes it so when you pull the bed out to be the queen size, the “bump” created by the slide disappears because the Hypervent fills the difference. Double-duty.

We’ve paired that with a Eva-Dry E-333. I was completely unaware of these things before… even after all my years around boats. Basically, it’s a giant silica bead container that uses no batteries or power. When it’s “full”, you simply plug it into a household outlet until the beads turn orange. Then it’s ready to go again!

In practice, we’ve found we can eliminate all condensation by:

  • Keeping all the windows, especially the thermal pack windows, closed
  • Keeping the Eva-Dry in the camper at all times
  • Cracking either the roof vent or turn-buckle access door (not a window!) AND
  • Running the power roof vent on “suck” (pulling air out of the camper to the outside) while inside in the camper

Opening just a roof vent or window won’t cut it in colder and wetter climates. However, running the power roof vent on suck by itself seems to work in dry climates.