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stuey

Dehumidifier Use In Caravans

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Guest JohnKS

We have never had any damp in our caravan either and have never used a de-humidifier!

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We have never had any damp in our caravan either and have never used a de-humidifier!

 

And that somehow "proves" what?

That they cant help others where the van returns from use in damp conditions?

I think not.

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Guest JohnKS

And that somehow "proves" what?

That they cant help others where the van returns from use in damp conditions?

I think not.

 

 

Wasn't trying to prove anything. I agree that if there is damp caused other than by natural conditions then they can help to dry it out but under normal circumstances I am not sure they really help.

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My experience has been until this year, come November put one of the cheap damp packs in the caravan (the ones you used to buy from Woolies and use in cupboards etc), also place fan heater on frost stat in the caravan and operate the fan every night for 1 - 2 hours on a timer.

Now this thread has made me think am I doing right, not had any damp using this method, but no longer have Economy 7, so am I wasting my money with the fan heater and moisture absorber?

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I agree that if there is damp caused other than by natural conditions then they can help to dry it out but under normal circumstances I am not sure they really help.

 

Thanks

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So what would happen to the water that collects in the dishes? does it just stay in the air?

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I must agree with Klarky

 

Dehumidifiers are a waste of time, money and environmentally unfriendly.

 

Why do you want to dry out the earths atmosphere. We need water!

 

Scales

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So what would happen to the water that collects in the dishes? does it just stay in the air?

 

Yes, but then the air inside the van and outside will have the same relative humidity (RH).

 

Dry the air with a dessicant which absorbs the water, and more moisture will be drawn into the van with the airfow flowing through the vents. Once the dessicant has absorbed as much water as it can, once again the RH inside and out will be the same. Dessicants absorb water slowly, probably at about the same speed at which moisture will enter the van to replace it.

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Guest JohnKS

Having just watched the programme on BBC 1 with the cyclists powering a house for a day, the best thing we can do with de-humidifiers is take them to the nearest tip. Got to be one life things we can do without unless there is a real reason for their use. Certainly drying out a caravan is not one of them!

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No but drying the air in my house is,thats why it was brought. Fed up with condensation & mould. Options,buy a dehumidifier or a new house,the second isnt an option yet

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Foor several years we have brought our caravan to southern Spain in mid-November to spend the winter. Also for several years I have transferred our dehumidifier from the house into the caravan where I've left it working - controlled by its humidistat - for the six weeks prior to our departure. Some years ago I wrote either on this forum or on T&T about my experiments with the dehumidifier in the van together with two identical hygrometers, one in the caravan and the other outside in the open air. The results taken over a number of weeks convinced me that I wasn't wasting my time.

 

I disagree with those people who hold the opinion that the dehumidifier is "trying to dry out the world". Maybe a small quantity of damp air passes into the van from the outside, but I don't agree that damp air is being "drawn in".

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Foor several years we have brought our caravan to southern Spain in mid-November to spend the winter. Also for several years I have transferred our dehumidifier from the house into the caravan where I've left it working - controlled by its humidistat - for the six weeks prior to our departure. Some years ago I wrote either on this forum or on T&T about my experiments with the dehumidifier in the van together with two identical hygrometers, one in the caravan and the other outside in the open air. The results taken over a number of weeks convinced me that I wasn't wasting my time.

 

I disagree with those people who hold the opinion that the dehumidifier is "trying to dry out the world". Maybe a small quantity of damp air passes into the van from the outside, but I don't agree that damp air is being "drawn in".

 

 

Equilibration is a scientific fact. All gases (including moisture vapour) will 'exchange' between areas unless there is a semi-permeable membrane preventing it. ..IN TIME!

Trying to change a selected area that is not totally isolated from the outside environment may in the short term result in a difference determined by the size of the venting holes. But once the driving force is removed the state of equilibrium will be re-established.

 

The key is how long it takes to do this and whether the local reduction of humidity in the meantime has any real benefit

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Using a Dehumidifier in the Caravan can be a waste of time and will not work up to the mark as it does in home.

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I had a compressor type for my conservatory but they only work if the space does not get cold.  It failed just on 2 years.

 

In this house I have the other kind and it really works well.  It uses a dessicant that is continually regenerated and pulls several litres out each day.

 

https://www.amazon.co.uk/dp/B00474K8SY

Edited by kelper

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A lot of knowledge in the marine world about dehumidifier use in boats in winter...   There are two factors to bear in mind.  Despite the comments made about "drying the world" you do need a bit of ventilation.  Secondly, the humidity of the air changes with temperature.  When temperatures drop near or below freezing, dehumidification is a waste of time, because most of the water is out of the air anyway, so if using a refrigerant based DH, put it on a simple time switch, otherwise the DH just freezes up.  If using a dessicant DH (which is what I use on the boat) then they actually monitor the humidity and will go into standby when at the right level...  The dessicant type does produce a bit of background heat which is beneficial in this sort of usage...

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It's that time of year so it comes as no surprise that the 'dehumidifier' topic has opened again.  :)  And also the time when I set up my 12volt dehumidifier in my van in preparation for going away with it in a few weeks time.     Between now and when I board the ferry, it will run for several hours each day, keeping the atmosphere and more especially, the upholstery dry.   Three days ago, when I took the dehumidifier in there, the reading in the van was 82%.   Now it's a much better 63%, whilst outside it's 97%.     If that means I'm trying to "dry out the world", - ok, I'm happy to try.   But does it works the other way?   If damp air is being sucked in, isn't warm air being pushed out when the fire's on.   So why put the heater when you're cold.   You're attempting to heat up the world????.:ph34r:

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4 hours ago, johny5 said:

Using a Dehumidifier in the Caravan can be a waste of time and will not work up to the mark as it does in home.

What  made you resurrect a ten year old thread just to say that it is a waste of time ??

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I've always used dehumidifiers in caravans.  Its a metal(?) box afterall.  For the winter, I take out all cushions but the matteress and leave at home.  I raise the matteress for air to circulate.  I don't have a water heating system.  But I use the defumidifers with crystals (or cat litter as that's what it looks like:D), and I change the crystals roughly every 2/3 months.  I have three in the caravan, one at the very front, one on the kitchen and one in the bathroom at the back.  Its very surprising how much water you get (I don't say damp, as it is water)

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I have used a dehumidifier in my boat for many years.  I can confirm that it works as I discovered one year when I did not bother.

 

I have owned several dehumidifiers over the years.  All have been the compressor type.  They have all had a humidistat so that they only operate when the humidity is higher that my chosen level.  They also shut off automatically if they start to accumulate ice.

 

I have never used a time switch.  If the air is too humid then  I want it drier, regardless of the time.

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I have owned motorhomes and caravans for a good few years now. This subject is one that recurs with considerable regularity on many forums, often with the same arguments being put forward. 

 

My own experience is that de humidifiers are pretty much a waste of time in a caravan UNLESS it is subject to water ingress (which no-one has yet mentioned) 

 

I have never seen the need for one in any of my leisure vehicles. They were/are fully equipped ready for a “quick getaway” if the mood takes us so I never bother to remove cushions or bedding from any of them over the winter. I have never found them to be damp or mouldy. What I DO ensure however is that there is always plenty of ventilation (the same as my house) 

 

I have never ever used any form of heating when not occupying the caravan. My  theory being that heating the air within the caravan DOESNT remove any moisture, all it does is heats the air up  so it is able to carry more moisture in suspension. Once the heating is removed the structure of the caravan cools slightly, so the moisture that WAS held in suspension then condenses out onto the colder surfaces. If everything inside (surfaces and air) is at the same temperature then there is no “cold” surface for the moisture to condense out onto and THAT is why a well ventilated caravan will not need any form of dehumidifier. 

 

My caravan  is parked alongside my house and is exposed to the prevailing weather, I leave a couple of the “downwind” windows cracked open on the first window catch,

 

Others (who have them) will I know disagree with me, that is of course their right, I have just posted an alternative point of view and a regime that has worked for me for many years now. 

 

It’s a bit like some feel the need to put a car in a garage every night whilst others are happy to leave them outside, neither option is “wrong” just different.

 

And

 

 

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When my narrowboat was unoccupied, we always left the half-windows open.  The marina water got very cold, it often iced over.  We never had any damp in the boat.  Andy's right.  Lots of ventilation is good.

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One point that hasn't been mentioned here is that the source of water isn't just external. Gas appliances produce huge amounts of water from combustion.  So when you cook on gas you get phenomenal amounts of water from the gas.  In my boat I had a Wallas diesel cooker, and the combustion was "sealed" in that it all exhausted to the outside.  Unfortunately the cooker failed and has been replaced by gas, and in the two years since the change the amount of water removed by the dehumidifier has increased noticeably...

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On 01/12/2009 at 03:33, stuey said:

Don't know if this topic has been covered before. Brought a dehumidifier for the house last week  ....................................

 

 

:goodpost:

 

Now added to Quick find index

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