I use a ecoair deccasant type one use it over night stops all condensation on the windows I only use it really as I bought it when I had a boat moored in Weymouth so may aswell put it to use rather than leave it in the garage
We used to carry one all the time on our RV travels. Great for dryng wet/damp cycling clothes and keeping the place warm when on. Needs electric hook up though. Don't have it in the PVC, not enough space
Yes, in wintertime a dehumidifier is a really good idea to keep the condensation at bay from wet coats/dogs/towels. We use a Meaco dessicant type as these will work down to low temperatures whereas the compressor types tend to stop working at around 10C.