Do you mean in your caravan over winter? In my opinion they are completely unneccessary if your caravan is dry and if your van has damp then it won't help. There is another thread running on this somewhere.
Several threads about this, do a search. A caravan has ventilation points that you should ensure arn't covered. This allows the air to circulate in & out of the caravan. Drying a small amount of this air & storing the moisture in a dehumidifier serves no purpose imho.
Agree. Any dehumidifier will absorb moisture and give the impression you have a damp problem, but a properly aired van, venting naturally as per Tentz post, will get through the winter with no problem.
Save your money.
beg to differ i use one on many occasions.i do not have a damp problem anywhere.i do know it makes the feel and the moisture content of the van a lot less.ours is on a timer 6 hours a day when switched on at the mains.many say i am trying to dehumidify the world,but i say it has to do the van first before more air can enter.works for me.each to there own.there was last week two users of expensive covers both were having condensation problems.so for me a cover is out.
------------- the only silly question is the one you do not ask.