Hi All
Just about to have our first Chrismas in the caravan,just a quick question regarding heating up the van,it has been in storage for 2 months and I am wondering about when I get to site and need to switch on heating do I put it on full or build up heat gradually as to stop any condensation? By the way I have truma blown air and a small fire unit
Condensation is all about the air's ability to carry moisture. In relatively simple terms warm air can carry more moisture than cold air, that is why blowing warmed air over wet washing allows it to remove moisture from the washing, but it also means that if you have warm air that has absorbed more moisture, when it comes into contact with a cool surface, the air cools and it can't carry all its moisture so it deposits it as condensation on the cold surface. (That's also how how condenser driers work!)
There's no problem warming up the caravan, you can warm it as quickly as you like. and it doesn't matter whether you use electrical or a properly designed touring caravan gas heater, as neither adds any moisture to the air in the caravan. Proper gas heaters (e.g. Truma and other besoke manufactured caravan heaters) are room sealed meaning no flue gasses enter the living space, so all you get is the air inside the made warmer ( and drier)
However if you use an open flamed appliance ( like a gas cooker ring or gas oven which doesn't have a dedicated flue to the outside then they will add moisture as a result of the combustions process. Humans and animals also raise the moisture level when they breath out, and that's why condensation is most often found in the mornings when teh caravan has been occupied and the ventilation has been at a minimum.
After using the caravan, the level of moisture in the caravans materials including the wood and fabrics will have risen becasue its been warmer, so when its put back into storage, and it it cools down the ability of the materials to hold the moisture reduces, so they also begin to release their moisture until it matches the moisture content of the ambient air.
To minimise the after use/storage condensation ventilation is very important. Lift or even remove all soft furnishings to allow full free flow ventilation around the caravan, and after a few days the levels of moisture in teh fabric of teh caravan will fall to match and track the moisture level of the ambient air.
Some caravanner's mistakenly think that a dehumidifier should be left running during storage - after the first couple of days it will not make any difference, except costing the user money to run the unit or to replenish its crystals.
If you do have a persistent condensation problem during storage, then its more likely to be a water leak of some sort allowing water into the caravan - get it checked out, as water ingress issues can become very costly to put right.