Okay-- from my original post of winter camping-- temps ran down to about 23 and i am seeking ideas for protecting the fresh water drain valve from the freeze and breaking as would your outside house faucets-- one idea would be the styrofoam covers i use on the outside faucets-- but we expect 23 again tonight--- so i will be wrapping best i can around that pipe-- taping will not hold on the foam under carriage-- the other solution was to also wrap and protect the water pump from the cold inside -- left the hatch open with minimal heat during the night of about 50 degrees and worked fairly well-- anyway-- most about protecting the drain valve-- thanx - sherpa san-- am thoroughly enjoying the trailer---
One area to check for condensation is above trailer openings like hatch access below bed or dinette seating. If you feel cushions or mattress you may find them damp. Keep in mind it's the cold/warm interface and designing an air gap like Hypervent will break link.
I learned how wet things can get boating in the Pacific Northwest. I painted plywood under mattress so it was impervious and could feel moisture easily and wipe up without soaking plywood. Checking mattress underneath in V berth you could see the wettest area was at the body mid torso due to highest body heat. Got Hypervent and this remedied problem but try to have edge(s) open to air circulation.
With our E19 I put Hypervent under mattress and surrounding outside edges against walls. I am planning to do something similar around dinette cushions.