Condensation - I didn't expect that would happen (1 Viewer)

SuperMike

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I do alllllllllllll the cooking and washing up LarryHarry fellow, 'cos I is a good boy. But to answer your question, my previous post had nothing to do with washing up, or, yellow snow. :p
 
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2657

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have never heated a van and had no problems ever....all you need is ventilation

you will enjoy this David :)

http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/relhum.html

all dehumidifiers do is suck the water out of the available air..pointless IMO

Yes that's what they do but I fail to see why it is pointless inside the confined space of a motorhome. They do not 'suck' air into the space so the air is changed by natural ventilation and the aim is to reduce the humidity not eliminate it.

It's like saying that all heaters do is heat the available air or that all air conditioners do is cool the available air

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DavidG58
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Thinking about some of the above, my MH has three dial indicators over the door, a broken clock, a temperature indicator and I think humidity

Don't look at them so not sure if the last 2 are inside or outside, but something else to check next time I look
 

Judge Mental

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Yes that's what they do but I fail to see why it is pointless inside the confined space of a motorhome. They do not 'suck' air into the space so the air is changed by natural ventilation and the aim is to reduce the humidity not eliminate it.

It's like saying that all heaters do is heat the available air or that all air conditioners do is cool the available air

how does heating and not ventilating balance out the temp inside with outside that I though created the condensation..its all about air flow surely
 

funflair

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Thinking about some of the above, my MH has three dial indicators over the door, a broken clock, a temperature indicator and I think humidity

Don't look at them so not sure if the last 2 are inside or outside, but something else to check next time I look

Hi David

It will most likely be barometric pressure rather than humidity.

Martin

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2657

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how does heating and not ventilating balance out the temp inside with outside that I though created the condensation..its all about air flow surely

Did I say that? Doesn't read that way to me! " the aim is to reduce the humidity"

Apparently( after the Physics lesson) what causes condensation is warm damp air coming into contact with a cold surface, dehumidifiers reduce the water content of the air inside the van thus reducing the likelihood of condensation.

Something to do with dew point I believe but I was never very good at Physics, managed to fail it at A level.
 

Peter Sansom

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We use those dehumidifiers that can be plugged in at home to dry out and use again. Have couple of them on the dash and don't seem to get any condensation on the windscreen. No heating in the van as it is parked away from the house. No probs...so far.

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Theonlysue

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Have you got external silverscreen you can use?
 
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DavidG58
Feb 24, 2013
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Have you got external silverscreen you can use?

Don't like them Sue, too bulky, quite hard to fit on an A class, wet to put away, delays leaving, stops quick get away if needed and I am too tight to pay for them :D

It seems to have a been a one off, dropped down to 1C here last night not a bit of condensation this morning

Only other difference, I removed 1/2 litre of moisture with my Karcher last time and heating now reduced to 6C
 
Feb 22, 2011
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I found them quite easy to put on for first time last April with no previous knowledge or experience of them. Would put them in shower to dry if necessary. Don't know cost as they came with van.
Never felt the need to plan for a quick getaway !

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Sep 10, 2013
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Don't like them Sue, too bulky, quite hard to fit on an A class, wet to put away, delays leaving, stops quick get away if needed and I am too tight to pay for them :D

It seems to have a been a one off, dropped down to 1C here last night not a bit of condensation this morning

Only other difference, I removed 1/2 litre of moisture with my Karcher last time and heating now reduced to 6C

It was the warm air carrying a high volume of water vapour looking for somewhere cold to dump it. Now the air in the van is nearer external temp and much cooler it can't carry the water vapour and therefore less chance of condensation.
Pleased it seems to be ok now.
 

laird of Dunstan

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The basics of condensation have been stated very well and that is warm air on a cold surface = condensation. I will resist the urge to rabbit on about dew point and relative humidity or the effective ness of small dehumidifiers in vented areas.
I would reduce the internal temperature and fit and external blanket on the windscreen ,I would not go below 5 Dec c for frost protection
 
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2657

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What about when you are occupying the van, gets a tad cold at 5 degrees.

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mustaphapint

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Using a dehumidifier is certainly not pointless. It's a bit like saying there's no point in heating my van or house to make it more comfortable because the heat that escapes will start heating the rest of the world. Assuming a van is naturally ventilated the humidity of the inside will change as the humidity of the outside air changes. Warm air absorbs moisture and cold air causes it to condenses. Where do you think the condensed water goes inside the van when the cold night air causes the moisture absorbed during the warmer day to condense? Mainly in the soft furnishings, bedding, mattresses, curtains etc. It's not normally a problem when the vehicle is in daily use but certainly can be when it's parked up for long periods in the winter. Yes of course once the air in the van becomes drier when using a dehumidifier than the outside air the natural ventilation into the vehicle will introduce humidity again and to a certain extent you will be drying out the local county, but the van will still be a lot drier than the outside air. Yesterday the humidity in our van was 60 degrees with the dehumidifier off and the door open. The dehumidifier will maintain it at 30 degrees with the door shut. In the end it's whatever works for you and at the moment we are fortunate enough to be able to park next to the house with EHU. Even on a dry day the fan in the unit keeps the air circulating in the van. We learnt the hard way after the first winter of owning a static caravan even after leaving all the windows slightly cracked, cupboards open and the curtains held back off the windows. We still had mouldy net curtains after leaving it for the enforced 2 month site closure. We also use a dehumidifier in our home in Brittany when it's left during winter and there is definitely a difference when we visit it now compared to how it used to be before we started using the machine.
 

Lenny HB

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I don't get it, a few people on this thread have said they like to keep their vans heated ready to go with water in the tanks.

To me that is not a good idea, chlorine disperses in water after a few days, after that bacteria starts forming so why would anyone want to use their van with a tankful of bacteria laden water.
It only takes a few minutes to drain a van down and only 5-10 min to refill the tanks with fresh water and if it's cold put the gas heating on while filling, all done by the time you have loaded any bits & pieces you need for the trip.
 
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DavidG58
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@lennyhb

I am one of the keep it full and ready crowd, partly lazy to be honest

But we never drink the water from the tank so not overly bothered about bacteria as most of it is going through the boiler before we see it next, not sure I that explains it any better, if not the lazy bit will have to suffice from me :)(y)

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Jan 21, 2015
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Hi, @DavidG58 and @dpsuk99. I too have the Alde wet system and my instruction book tells me not to have the heating on constant at low temperature when laid up. The book says use the 'delayed start' feature which puts the heating on for up to 24 hours at a normal temp once a week. This supposedly gives the MH a good regular airing and I haven't had any condensation probs yet. I also leave the internal blinds closed and I drain all water when laid up so there is no water onboard to freeze.
 

laird of Dunstan

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I can see us heading for a discussion on legionella bacteria here :) as for condensation ,it probably account for 20% of my work load during the summer months ,during the colder months it is a rare occurrence.
I can stand inside the machinery that is used for dehumidifiers in my work places ,they are all very energy inefficient,I never said that they are pointless ,its their Effectiveness's and waste of energy that I question.:)
I with David on the being lazy brigade (y) but I do disenfect the water tank ,you should also descale the taps and disenfect the shower hoses and heads :whistle:
 
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DavidG58
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Hi, @DavidG58 and @dpsuk99. I too have the Alde wet system and my instruction book tells me not to have the heating on constant at low temperature when laid up. The book says use the 'delayed start' feature which puts the heating on for up to 24 hours at a normal temp once a week. This supposedly gives the MH a good regular airing and I haven't had any condensation probs yet. I also leave the internal blinds closed and I drain all water when laid up so there is no water onboard to freeze.

Thanks for that, my manual either contradicts that, doesn't mention it, or far more likely I have not yet read that far into it :):D

I don't drain my water, so am not too keen on the once every now and again options, but then not very keen on condensation either (y)

Does the book say why not to use it on low setting? I cant really see how the Alde system would know, the thermostat is only effectively a switch, would it know whether the temp is 6 / 16 or 16C, it will still run till told to turn off surely?

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DavidG58
Feb 24, 2013
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I can see us heading for a discussion on legionella bacteria here :) as for condensation ,it probably account for 20% of my work load during the summer months ,during the colder months it is a rare occurrence.
I can stand inside the machinery that is used for dehumidifiers in my work places ,they are all very energy inefficient,I never said that they are pointless ,its their Effectiveness's and waste of energy that I question.:)
I with David on the being lazy brigade (y) but I do disenfect the water tank ,you should also descale the taps and disenfect the shower hoses and heads :whistle:

Legionella :mad:

As a buy to let landlord I have been forced to get my tenants new shower heads due to perceived 'risk' like the boiler servicing, I don't want to cut corners / take risks, but if there is a risk to my tenants is there no risk to my family, why does the government not force all households to do the same not just look after the rent payers:mad:

Good point well made though, thank you your lairdship :)(y)
 

laird of Dunstan

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i need to keep an eye on the shower heads too david ,i rent out one house at the mo , but part of my paid job is to dunk the shower head and attached hose into disenfectant and this covers current legislation , id check on that one .:D
 
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Thanks for that, my manual either contradicts that, doesn't mention it, or far more likely I have not yet read that far into it :):D

I don't drain my water, so am not too keen on the once every now and again options, but then not very keen on condensation either (y)

Does the book say why not to use it on low setting? I cant really see how the Alde system would know, the thermostat is only effectively a switch, would it know whether the temp is 6 / 16 or 16C, it will still run till told to turn off surely?
Dave, attached is an extract from the full Alde Heating Manual (available online) which recommends the delayed start function for storage. This does require the water to be drained down as frost can affect during the 6 days the heating is not on. I can't find the reason why this method is the preferred one, but memory seems to tell me that it is to do with the constant running of the pump and of course the effect on its lifespan.

upload_2016-1-11_10-28-12.png

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DavidG58
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Thanks @Pete D.

I can understand the logic of occasional heat and running the system to keep aired when stored, but still don't really get why you cant run it constantly, there must be people using them over winter near constantly who will run heating as needed, all using different set temperatures

The good news for my condensation is that it seems to have been resolved (y) at least while we are not in it :D
 
Jan 21, 2015
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@DavidG58 - I suppose it's all about our needs and circumstances i.e. needing to heat the moho when you are using it and when you're not. Glad to hear the condensation has gone away. :)
 

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