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stuey

Dehumidifier Use In Caravans

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Dont know if this topic has been covered before. Brought a dehumidifier for the house last week & gave it a run in the van for approx 4 hrs at the weekend. It collected about a mugfull of water,i was amazed(mind you it collected about 2 litres in the house in about 1 day when first used).I now plan to use it in the van about once a week or more to dry the air out. There is one model that doesnt have a compresser called an absorbtion dehumidifier which is better used at lower temps so would be ideal for caravans and the air they expell is quite warm so heats the space as well. If you keep the relative humidity below 50% mould should not grow apparantly. Has anyone else used one in their van?

Edited by stuey
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Dont know if this topic has been covered before. Brought a dehumidifier for the house last week & gave it a run in the van for approx 4 hrs at the weekend. It collected about a mugfull of water,i was amazed(mind you it collected about 2 litres in the house in about 1 day when first used).I now plan to use it in the van about once a week or more to dry the air out. There is one model that doesnt have a compresser called an absorbtion dehumidifier which is better used at lower temps so would be ideal for caravans and the air they expell is quite warm so heats the space as well. If you keep the relative humidity below 50% mould should not grow apparantly. Has anyone else used one in their van?

 

any kind of de-humidifier,or absorbtion crystals are a waste of time when used in a caravan. there are gas drops,vents for fridge etc where moisture will actually be drawn in by the dehumidifier,therefore constantly accumalating water in the tank. take the cushions off the seats and place on the floor to allow air to circulate underneath,any bedding take home if not used for winter____but dont use any moister absorbtion devices___they dont work to the level they would in your home,and could even cause more dampness than it would if not usedwink.gif

Edited by klarky

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Guest JohnKS

Completely agree with klarky. Complete waste of time. ! How do you know that the water collected in the container is from the van? It is more than likely to be from the air outside, drawn in by the de-humidifier making the van even more damp.

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I actually had a letter printed in Caravan Club Magazine a couple of years ago on this matter. .... I was in a local dealer talking to their Service Manager at the same time a couple were changing dealers because they thought that the information they were given about water in the van and de-humidifiers was wrong. .... They kept their 'van inside a garage and ran a de-humidifier every day. ..BUT they had not sealed up any of the vents ands were therefore pulling air from outside into their 'van. ........!!!...they didn't believe that this was relevant. .....

 

 

rgds

geoff

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I don't agree with the sweeping, unqualified statement that de humidifiers are a "Complete waste of time!"

Quite correctly they are a waste of time if frequently left running in a stored caravan as because of the relatively free venting of the van you end up attempting to dry out your village etc.

 

But this totally misses the point that if used directly after using the van in damp humid conditions they are excellent at removing the excess moisture that arises from human habitation of the van. Yes you can wait for the natural airing process to pull this excess moisture out of the upholstery, the drapes and from poorly ventilated surfaces like in bedboxes and behind curtains, but we know to our cost that mildew can get to that moisture faster than natural airing can.

If you only caravan in nice dry weather then there is not much point in buying a dehumidifier, and it will not be needed during sustained storage.

But as I said this misses the situation where they are very effective indeed.

Edited by JTQ
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Interesting answers but not quite what i expected. Surely wherever they are used they could draw air in from an external source other than where they are placed. I am sure the supplier where mine came from would beg to differ with some of the negative comments made. See the link for the absorbtion model i mentioned.

 

http://www. dehumidifiers-direct. co. uk/contents/en-uk/d69_premiair-dd122fw. html

Edited by stuey

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Interesting answers but not quite what i expected. Surely wherever they are used they could draw air in from an external source other than where they are placed. I am sure the supplier where mine came from would beg to differ with some of the negative comments made. See the link for the absorbtion model i mentioned.

 

http://www. dehumidifiers-direct. co. uk/contents/en-uk/d69_premiair-dd122fw. html

Hi Stuey,

 

Of course the supplier would beg to differ, otherwise there would be no point in selling them.

 

The big issue with caravans as opposed to houses is that with a house you have limited air vents, windows and external doors are well sealed so the dehumidifier is only extracting moisture from the air in the room.

 

A caravan on the other hand, as has previously mentioned, even if you close all the windows and roof vents there is still a degree of ventilation built into them, then if you consider the drop vents in enclosed spaces the caravan is still like a colinder.

 

So for every litre of air you remove moisture from, the ventilation allows more fresh air in, which carries more moisture.

 

The item you have linked to has an average power consumption of 620w, if you are near enough to a power supply to plug the de humidifier in, why not just leave the caravans electric heating on its lowest setting.

 

This will raise the mean temperature above dewpoint and remove the need to dehumidify.

 

Steve

Edited by Grandpa Steve
Added text

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Interesting answers but not quite what i expected. Surely wherever they are used they could draw air in from an external source other than where they are placed. I am sure the supplier where mine came from would beg to differ with some of the negative comments made. See the link for the absorbtion model i mentioned.

 

http://www. dehumidif. ..ir-dd122fw. html

 

Hi Stuey

 

I read a story once of the National Trust (I think) trying to dry out a Martello tower and nearly giving up when they

got millions of litres of water, and realised all they were doing was wicking the water out of the ground!

The solution was to either 'tank' the walls and floor to stop fresh water coming in from outside or keep the units

going if the electricity cost was less than the remedial work.

 

A dehumidifier will drop the RH of the van air very quickly and then outside air will quickly replace the lost moisture,

and if the starts at 50% and balances on a wet day to 65% then unless the dehumidifier had a humidistat you can

make the van wetter!

In a draught proofed double glazed house a dehumidifier will 'work' but really they only excel at drying out say a

poorly vented bathroom or flooded properties in Cumbria. ..

 

neil

 

The seller will always tell you what you want to hear to sell anything, so take what they say with a pinch of salt

(which is the old method of de-humidifying - a tray of salt to be exact)

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Hi Stuey

 

I read a story once of the National Trust (I think) trying to dry out a Martello tower and nearly giving up when they

got millions of litres of water, and realised all they were doing was wicking the water out of the ground!

The solution was to either 'tank' the walls and floor to stop fresh water coming in from outside or keep the units

going if the electricity cost was less than the remedial work.

 

A dehumidifier will drop the RH of the van air very quickly and then outside air will quickly replace the lost moisture,

and if the starts at 50% and balances on a wet day to 65% then unless the dehumidifier had a humidistat you can

make the van wetter!

In a draught proofed double glazed house a dehumidifier will 'work' but really they only excel at drying out say a

poorly vented bathroom or flooded properties in Cumbria. ..

 

neil

 

The seller will always tell you what you want to hear to sell anything, so take what they say with a pinch of salt

(which is the old method of de-humidifying - a tray of salt to be exact)

 

cool.gifcool.gif ________WE DEFINATELY GETTIN THERE____but sadly we cant convince all_____at least we got dry vans lol

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Guest JohnKS

I don't agree with the sweeping, unqualified statement that de humidifiers are a "Complete waste of time!"

 

 

I said they were a waste of time in the circumstances the topic is about. I have just used ours to dry out a recently plastered bathroom. Door closed and window shut. Brilliant!!

 

They aren't any good in a caravan unless you block up all the holes and then as soon as you turn them off all the damp atmoshere returns.

 

You are better off putting some form of heating in. We turn our fire on in ours the night before we go away. Now that does work.

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Hi Stuey

 

I read a story once of the National Trust (I think) trying to dry out a Martello tower and nearly giving up when they

got millions of litres of water, and realised all they were doing was wicking the water out of the ground!

The solution was to either 'tank' the walls and floor to stop fresh water coming in from outside or keep the units

going if the electricity cost was less than the remedial work.

 

A dehumidifier will drop the RH of the van air very quickly and then outside air will quickly replace the lost moisture,

and if the starts at 50% and balances on a wet day to 65% then unless the dehumidifier had a humidistat you can

make the van wetter!

In a draught proofed double glazed house a dehumidifier will 'work' but really they only excel at drying out say a

poorly vented bathroom or flooded properties in Cumbria. ..

 

neil

 

The seller will always tell you what you want to hear to sell anything, so take what they say with a pinch of salt

(which is the old method of de-humidifying - a tray of salt to be exact)

 

ok obviously a lot against the dehumidifier use in the van. I have a hydgrometer to measure r/h. will check the van before dehumidifier use,run for a time,check the r/h then check the r/h again the next day,should give some idea unless anyone has a better idea. Not disputing the comments put forward but interested to see the results. Dont see though how you can make a van wetter by not having a humidistat. The stat on mine just stops the compressor working when a r/h has been reached,ie 50%.If you set it to constant it is continually drying the air so the r/h will come down even lower,resulting in a drier van not a wetter one surely

Edited by stuey

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ok obviously a lot against the dehumidifier use in the van. I have a hydgrometer to measure r/h. will check the van before dehumidifier use,run for a time,check the r/h then check the r/h again the next day,should give some idea unless anyone has a better idea. Not disputing the comments put forward but interested to see the results. Dont see though how you can make a van wetter by not having a humidistat. The stat on mine just stops the compressor working when a r/h has been reached,ie 50%.If you set it to constant it is continually drying the air so the r/h will come down even lower,resulting in a drier van not a wetter one surely

 

Stuey, I think you are missing the point. You may reduce the humidity for a while but it will still reurn to the original level as soon as you turn it off. By drying out the van you are attacting more damp as it has more places to go. Most houses and vans are slightly damp. Our weather station reads the humidity and it is often over 50%. Any less then we would be living in a dry haystack!!

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Stuey, I think you are missing the point. You may reduce the humidity for a while but it will still reurn to the original level as soon as you turn it off. By drying out the van you are attacting more damp as it has more places to go. Most houses and vans are slightly damp. Our weather station reads the humidity and it is often over 50%. Any less then we would be living in a dry haystack!!

 

Obviously when you stop using it r/h will return but you are drying out what is in the van. We leave bedding cushions etc in the van,some people take everythig out,due to storage space in our house we dont. The van is kept outside our house so no problems airing the van,heating it etc. Havent had any issues yet with dampness on any internal soft furnishings,just thought that the dehumidifier would take any slight dampness off bedding etc if used occasionally. As for any less than 50% r/h,it is reccomended to take it down to 40% 0r less to stop excessive condensation on windows in your home. The running cost of it should be offset by using your other forms of heating in the house. ie,gas less as drier air is easier to heat than moist air

Edited by stuey

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Whilst you are using a dehumidifier you are not targeting humidity but damp[free water]; your only interested in locally reducing the RH so any "free water" can be evaporated. For that purpose the dehumidifier works just as nature intended. Dead simple science; lower the RH and any free water tends to evaporate better than before.

We are not using dehumidifiers in some belief we can obtain any specific RH, but that using it we are inevitably at a lower RH than without it and hence drawing free water from the van. Clearly I know some, even most will come from outside but I also know some will come from inside and that's exactly what I am using it for.

After using it then it matters not that the RH will drift up and down with the weather as we know the free water that facilitates the fungi and bacteria is no longer there.

Edited by JTQ

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Guest JohnKS

Whilst you are using a dehumidifier you are not targeting humidity but damp[free water]; your only interested in locally reducing the RH so any "free water" can be evaporated. For that purpose the dehumidifier works just as nature intended. Dead simple science; lower the RH and any free water tends to evaporate better than before.

We are not using dehumidifiers in some belief we can obtain any specific RH, but that using it we are inevitably at a lower RH than without it and hence drawing free water from the van. Clearly I know some, even most will come from outside but I also know some will come from inside and that's exactly what I am using it for.

After using it then it matters not that the RH will drift up and down with the weather as we know the free water that facilitates the fungi and bacteria is no longer there.

 

 

Hi JTQ

 

I bow to the greater knowledge obtained by a university degree!!!!! (You thought you had edited that out!!!!!!)

 

I just use commonsense and a grammar school education 50 years ago. Hey Ho!

Edited by JohnKS

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The comments are now starting to get a bit "dry"

:lol::lol::lol::lol:

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Guest JohnKS

The comments are now starting to get a bit "dry"

:lol: :lol: :lol: :lol:

 

Very drole!!

Edited by JohnKS

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Im sure Im only repeating whats been said but I will add my 2 cents anyway.

 

Dehumidifiers only truly 'work' when the indoors humidity is higher than outdoors. eg plasterwork drying out, flooding drying out, washing being aired indoors, steamy bathrooms etc. In other words when the mositure content of the air has been elevated unnaturally.

 

Unless you have boiled a kettle in the caravan or run the heater on gas, the inside humidity will always be the same as outdoors given the roof, floor and fridge vents. So putting any form of dehumidifier in a caravan without hermetically sealing it from outdoors is a waste of time, unless you are specifically drying out damp spots, as it will equilibrate within hours.

 

Whats more important is air circulation.

Edited by ericfield

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Im sure Im only repeating whats been said but I will add my 2 cents anyway.

 

Dehumidifiers only truly 'work' when the indoors humidity is higher than outdoors. eg plasterwork drying out, flooding drying out, washing being aired indoors, steamy bathrooms etc. In other words when the mositure content of the air has been elevated unnaturally.

 

Unless you have boiled a kettle in the caravan or run the heater on gas, the inside humidity will always be the same as outdoors given the roof floor and fridge vents. So putting any form of dehumidifier in a caravan without hermetically sealing it from outdoors is a waste of time. It will equilibrate within hours.

 

Whats more important is air circulation.

 

 

LOL______AT LASTbiggrin.gifbiggrin.gif

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LOL______AT LASTbiggrin.gifbiggrin.gif

 

 

I suppose alternatively we could leave the fridge on with the door open LOL

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I suppose alternatively we could leave the fridge on with the door open LOL

 

and fill the sinks and shower tray with water and maybe keep the kettle boiling lollaugh.giflaugh.gif

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OK, will come out from lurking in the shadows to confess.

 

I had been clearing out the van so connected the EHU to get some light and left it connected to charge the battery. It was plugged in via a power meter, and as I was passing the meter a couple of days later I noticed that the van was consuming 110W. Thats a bit high for a battery that has been on charge for a couple of days, so I pulled the plug.

 

Back in the van I the weekend, (with it plugged back in) and I notice the fridge power light on.

Doh! I had left the fridge on, with the door open. So it had iced up, then defrosted when I had pulled the plug. The bottom of the fridge was swimming in water, luckily I don't think it had overflowed on to the carpet.

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We have a couple of dehumifiers. One does permanent duty in the utility room for drying clothes hung in the utility, much cheaper than using the condensing drier if there is no desperate rush for the clothes. We run a fan to stir the air round the clothes with the dehumidifier and they dry in no time at all. We have a second one located in the garage which is sometimes prone to slight flooding, in which the car, motorbike and lots of expensive tools are stored in its ajoining workshop. It dries that out in no time and set very low, it only rarely runs, but nothing rusts in there.

 

Come autumn, the garage dehumififier is put in the caravan for a week to draw as much moisture as it can from the inside of the caravan - so the caravan at least starts its winter dry. A tiny amount of heeat will be continually generated by the built in charger, keeping the battery topped up. It seems to work, we have never suffered any sort of damp problem in the caravan.

 

I really cannot see how using a dehumifier in a caravan could make it damper. Not very scientific, but - Out of curiosity I have just checked the RH outside in the garden and it shows 76%, in the caravan it reads 55% and with no help from a dehumidifier for a few weeks. Indoors it reads 41%.

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We have a couple of dehumifiers. One does permanent duty in the utility room for drying clothes hung in the utility, much cheaper than using the condensing drier if there is no desperate rush for the clothes. We run a fan to stir the air round the clothes with the dehumidifier and they dry in no time at all. We have a second one located in the garage which is sometimes prone to slight flooding, in which the car, motorbike and lots of expensive tools are stored in its ajoining workshop. It dries that out in no time and set very low, it only rarely runs, but nothing rusts in there.

 

Come autumn, the garage dehumififier is put in the caravan for a week to draw as much moisture as it can from the inside of the caravan - so the caravan at least starts its winter dry. A tiny amount of heeat will be continually generated by the built in charger, keeping the battery topped up. It seems to work, we have never suffered any sort of damp problem in the caravan.

I really cannot see how using a dehumifier in a caravan could make it damper. Not very scientific, but - Out of curiosity I have just checked the RH outside in the garden and it shows 76%, in the caravan it reads 55% and with no help from a dehumidifier for a few weeks. Indoors it reads 41%.

 

Hi harry. m1byt

 

Well that's a reference to my poorly worded early post, and what I meant to say was that just dehumidifying for a bit without reference to the

current RH could mean that the van is either dried unnecessarily (if 'dry' already say) and the dehumidifier doesn't have a humidistat, you then

pack the van away to the surroundings having wasted time and electricity and it balances the RH anyway. ..

 

As your figures amply demonstrate the RH changes all the time and without a humidistat equipped dehumidifier on full time you would just be

wasting your time, I think you may be right to just boost dry the van occasionally as it may be the reason the van is a lower reading than

garden (but not the house) - or just leave it to stabilise the RH naturally. ..

 

neil

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We have a couple of dehumifiers. One does permanent duty in the utility room for drying clothes hung in the utility, much cheaper than using the condensing drier if there is no desperate rush for the clothes. We run a fan to stir the air round the clothes with the dehumidifier and they dry in no time at all. We have a second one located in the garage which is sometimes prone to slight flooding, in which the car, motorbike and lots of expensive tools are stored in its ajoining workshop. It dries that out in no time and set very low, it only rarely runs, but nothing rusts in there.

 

Come autumn, the garage dehumififier is put in the caravan for a week to draw as much moisture as it can from the inside of the caravan - so the caravan at least starts its winter dry. A tiny amount of heeat will be continually generated by the built in charger, keeping the battery topped up. It seems to work, we have never suffered any sort of damp problem in the caravan.

 

I really cannot see how using a dehumifier in a caravan could make it damper. Not very scientific, but - Out of curiosity I have just checked the RH outside in the garden and it shows 76%, in the caravan it reads 55% and with no help from a dehumidifier for a few weeks. Indoors it reads 41%.

 

hurrah,someone finally agrees that a dehumidifier cannot make a van damper,it DRIES the air!!!

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