Dehumidifiers

[Jem1]

Does anyone use a dehumidifier for when the van is stored up for the winter ?? we're thinking about buying one but not sure whether its a wate of time or a must ??

We always cover our van up to and arrange the upholstery away from the walls.

 

[Parksy]

Don't waste your money Jem. There are so many ways for moist air from the atmosphere outside to enter your caravan that you will be attempting to dehumidify the entire neighbourhood rather than the inside of your caravan because any moist air that you remove will simply be replaced. Dehumidifiers always look impressive because the water storage containers are always full but for them to remain empty when the machine is switched on you'd have to be somewhere with no atmosphere like the moon or West Bromwich

 

[littlebasher]

At South Yorkshire caravans yesterday, i noticed a steady stream of people coming out with disposable dehumidifiers !

 

[GrahamDerby]

Must agree with Parksy. Unles you are going to seal every little vent you are waisting your time . Not sure about West Brom not been there but Brownhills is similar.

 

[trevor123]

Hi Jem, Don't waste your money on them if you do buy one you could end up with dry rot in you van, if you keep you van at home like we do, we put 2 crystals tub down on the floor one up each end and they do work better that way, on a nice winter dry day we open the caravan door to let in some fresh air, we been doing it that way for 26 years, good luck,

 

[JTQ]

They can be very useful, used for a few hours to pull excess habitation moisture from the soft furnishings and drapes immediately after you return from a humid period of caravanning, like so often occurs in the winter.
If you know how to use them they can be far from a waste of money.
Used continuously during storage though becomes rather pointless.

 

[Robtel]

Agree with JTQ. I have used one in my van over the the winter months for the past 10 years or so. Previous to that for approx the same time I had the van stored without dehumifier and can say there is a marked difference when one is used.

This topic comes up every year without fail and the variety of different reasons for not using one never ceases to amaze me. I can understand, though not necessarily agree, with the dehumidifying the world theory but some others? I've read - don't use them because they will make your caravan damper, don't use them because they will dry out the woodwork that badly it will crack, and now don't use them because you will get dry rot.
When I do use mine I set the humidity setting at a low to mid point and can go out to check the van and find that it has automtically switched off - it wouldn't do that if it was dehumidifying the world, it would just keep going.
Not using it I find that upholstery, mattress etc. has cold clammy feel to it. JTQ is right use it after an outing, I also use it for a day or two before going away.
I know most people say they are no use, but by having not used for a number of years then used one I would disagree. Most people who speak out against them haven't tried and tested using one.

 

[vauxhall2]

i use one all the time,its on timer of 6 hours a day during the winter unless there is a frost.some say i am trying to dehumidify the world but i say it has to do the caravan first.it makes the van feel warm and dry.

 

[Lutz]

I can see some point in using one immediately prior to going away with the caravan, but as humidity itself won't do any damage to it so long as it's well aired, I'd like to know where the benefit of a dehumidifier while in storage is supposed to be.

 

[RogerB]

Can/'t agree with you about the dry rot Trevor.Dry rot is a fungus that thrives in dark , damp and badly ventilated areas.The only timber that it would attack is the timber in the body construction and as this does not have any air,stagnant or otherwise,around it then there is very little chance of dry rot being a problem.Wet rot is far more likely.
In my opinion,the use of any dehumidifying device is a waste of time but unlikely to exacerbate or reduce any problems associated with moisture in a caravan.Regular venting of the inside on dry breezy days will certainly be beneficial.

 

[mcork]

Can't see a major problem with using one and certainly not dry rot (which is not dry by the way) apart from the cost.
We have always placed a few bowls of salt around the van, opened all the lockers and stood cusions etc on their side. Check salt bowls as they can fill with water
Never had any problems with damp

 

[ProfJohnL]

Hello mcork,

Your logic does not stand up. You imply that because you use bowls of salt, you don't have a damp problem. Perhaps you don't have damp problem because you are one of the lucky owners whose caravan does not leak?

Until you try without the salt you won't know. I know salt isn't massively expensive, and if you feel happier using it then that is your own choice, but the reasons for a dry van are more likely because your van is dry.

 

[Lutz]

Besides, as damp spreads from the outside and a dehumidifier can, at best, only dry the air inside, any damp will have already got into the wood before the dehumidifier has had a chance to do its job.

 

[parker1158]

As a scientist I’m firmly in the ‘should not need to use one’ camp unless you have a damp problem through having water ingress, this is largely where dehumidifiers are used – in basements and cellars particularly in hot countries or to dry out rooms after flood. A comfortable and accepted humidity level is around 40 – 60% this can be measured using an inexpensive hygrometer. It is generally accepted that under 40% one should humidify and above 60% dehumidify

One should also be aware that cold air holds less moisture, for instance at the poles there is close to zero humidity, the air is bone dry. That’s why in the winter your lips and skin are more prone to chapping. This is one reason why it is widely accepted that dehumidifiers start to become ineffective when the temperature falls below 60f, that’s 160c.

Then there are the health connotations associated with dry air, this from a medical journal,
The majority of adverse health effects caused by relative humidity would be minimized by maintaining indoor levels between 40 and 60%. This would require humidification during winter in areas with cold winter climates. Humidification should preferably use evaporative or steam humidifiers, as cool mist humidifiers can disseminate aerosols contaminated with allergens.
Before anyone gets on their soap box I’m not suggesting that your dehumidified caravan will kill you but just might leave you open to pick up a bug you would otherwise avoid.

Using a dehumidifier will not increase moisture levels...until it is turned off, there would then be a ‘surge’ of more humid air enter the area which would see a rise above ambient levels before settling to an equal level.
What most people perceive as damp in a caravan is likely to only be cold and I would agree that airing a caravan before use after a long period of laying dormant might well be prudent.
Clearly as temperature and humidity cause’s materials to expand and contract at different rates so too will your van, one assumes that caravan manufacturers take this into consideration when dealing with the design and use of products and work to parameters; does this extend to a van that is overly dry? I don’t know I’m not caravan technically minded but others on here are and might like to comment.
The other thing is that caravan owners are paranoid about damp and as such are every dehumidifier’s salesman’s dream so yes they will sell.

So my opinion a waste of time unless you have a damp problem but if you want to go to the expense of buying one and running it then I’m sure you will justify it. For me a window ajar and a low heat for an hour before use will achieve the same affect....Oh and salt...no way would i introduce salt into a caravan.

 

[Guzzles]

Well done Sir Tainly Barkin. Hopefully you've put this debate to bed!.