We have the Pegasus 462 2011 model .Last week I put our house humidefirer in there to see what damp air is in there. I got about 1ltr over 48 hours.Thought occured to to me today where its like a spring day here to switch the extractor on and clear the interior air out, is it a daft thing to do?.
Removing damp inside caravan
- Thread starter Robert_374373903
- Start date
Given all the fixed ventilation required in caravans by law there's a constant throughput of ambient air in the caravan - so running a dehumidifier in a constant supply of moist fresh air is pointless.
.......it is a very good thing to do if the Relative Humidity is low (below 50%)
I have a weather station and it tells me what the Relative Humidity of the air is inside my house and outside.
On a day like today it is reading 41% inside (heated) and 46% outside at the time of this post.
My caravan is stored next to my house so I have been out to switch on the high level 12 volt extractor fan.
All opening vents are shut as air comes in through the fixed vents mostly at floor level.
I have a weather station and it tells me what the Relative Humidity of the air is inside my house and outside.
On a day like today it is reading 41% inside (heated) and 46% outside at the time of this post.
My caravan is stored next to my house so I have been out to switch on the high level 12 volt extractor fan.
All opening vents are shut as air comes in through the fixed vents mostly at floor level.
RogerL said:
I agree with Roger
Because of the vents in a caravan, by using a dehumidifier you are just pulling more moist air into the van.
The same goes for using crystals & salt. A waste of time & money
Actually i don"t think it is a waste of time and money ( Crystals & Salt )
Since we brought our brand new caravan we have always put Crystals & Salt in through the winter months and we also have a Breathable caravan cover on, The Crystals we use lasts up to three months and so far they have been great.
Since we brought our brand new caravan we have always put Crystals & Salt in through the winter months and we also have a Breathable caravan cover on, The Crystals we use lasts up to three months and so far they have been great.
Hello Beachball,
My own professional opinion is that in a stored caravan and provided the caravan does not suffer from any water ingress problems then there is sufficient air exchange with the outside to render any dehumidification process ineffective, and thus using any form of dehumidification has no practical value.
Because of the amount of ventilation built into all caravans, you will find that dehumidifiers (of any sort) will collect moisture, but it is from the air passing passing through not from the structure or materials of the caravan.
As you have always used crystals and salt, you have no basis on which you can logically arrive at your contention. You can only make a valued conclusion if you have tried NOT using crystals and salt and found a difference.
I would venture to suggest that if you did find any difference, then you should be looking for water ingress.
My own professional opinion is that in a stored caravan and provided the caravan does not suffer from any water ingress problems then there is sufficient air exchange with the outside to render any dehumidification process ineffective, and thus using any form of dehumidification has no practical value.
Because of the amount of ventilation built into all caravans, you will find that dehumidifiers (of any sort) will collect moisture, but it is from the air passing passing through not from the structure or materials of the caravan.
As you have always used crystals and salt, you have no basis on which you can logically arrive at your contention. You can only make a valued conclusion if you have tried NOT using crystals and salt and found a difference.
I would venture to suggest that if you did find any difference, then you should be looking for water ingress.
John is too diplomatic - if damp is a problem in a caravan, it's leaking somewhere - natural moisture doesn't give a problem as caravans are ventilated. The caravan industry has perpetuated myths about needing to use dehumidifiers or hygroscopic crystals to absorb water to save itself the cost of repairing caravans under warranty.
All air has some natural moisture in it but the amount varies dramatically - but dehumidifiers/crystals will aLWAYS take some water out, only to find mother nature replacing it!
NOW is the time to air all the caravans in winter storage because the persistent cold temperatures have brought very low humidity, at around 10-20% RHI - which is way below the comfort level settings on any humidifier systems. It's also a good time to open the plugs in double glazing IF misting is a problem, let it fill with relatively dry air for a couple of days and then replug them.
All air has some natural moisture in it but the amount varies dramatically - but dehumidifiers/crystals will aLWAYS take some water out, only to find mother nature replacing it!
NOW is the time to air all the caravans in winter storage because the persistent cold temperatures have brought very low humidity, at around 10-20% RHI - which is way below the comfort level settings on any humidifier systems. It's also a good time to open the plugs in double glazing IF misting is a problem, let it fill with relatively dry air for a couple of days and then replug them.
Ive used two of the crystal type in my van and it collects a fair amount of moisture in the collection tray.
Year before last I didnt use them and found that there were "mouldy" patches appearing on various parts of the wooden units.
Used them last year, and had none of the "mould" problems.
Will continue to use them.
Year before last I didnt use them and found that there were "mouldy" patches appearing on various parts of the wooden units.
Used them last year, and had none of the "mould" problems.
Will continue to use them.
Hello GeorgeandAde,
Given the details of your report, then it suggests that you may have a damp problem with water ingress somewhere.
Given the details of your report, then it suggests that you may have a damp problem with water ingress somewhere.
Hi Prof.
I hope I havent and the last service in October at local Bailey dealer didnt show up any problems.
By "Mould",I would say its a powdery substance mainly towards the bottoms of a few units which readily wipes off with a damp cloth,but will keep my eye on it.
I hope I havent and the last service in October at local Bailey dealer didnt show up any problems.
By "Mould",I would say its a powdery substance mainly towards the bottoms of a few units which readily wipes off with a damp cloth,but will keep my eye on it.
Dealers seem to play down water-ingress, presumably because they'd have to fix it under warranty but as soon as you try to part-exchange it every caravan seems to be riddled with damp.
I just don't see how damp and/or mould can possibly arise without water-ingress.
I just don't see how damp and/or mould can possibly arise without water-ingress.
Condensation, which of course is a form of water ingress, causes damp and mould and occurs in houses as well as caravans where there is insufficient ventilation and the interior / exterior temperature difference is sufficient
We have always kept our van in a barn, with good ventilation. If we keep the van windows on night latch setting we don't ever experience mould, although occasionally there has been damp on the unit doors.
However, if the night vents have been left closed over winter we have experienced a light covering of white mould on occasions, as the condensation has not been able to dry out quickly enough, before the formation of mould growth.
Thoroughly cleaning all surfaces with disinfection wipes also helps to avoid this problem
We have always kept our van in a barn, with good ventilation. If we keep the van windows on night latch setting we don't ever experience mould, although occasionally there has been damp on the unit doors.
However, if the night vents have been left closed over winter we have experienced a light covering of white mould on occasions, as the condensation has not been able to dry out quickly enough, before the formation of mould growth.
Thoroughly cleaning all surfaces with disinfection wipes also helps to avoid this problem
Unless it's been modified, every caravan automatically has sufficient ventilation - the EN1645 standard ensures that the necessary ventilation is present in all caravans. These are fixed apertures which cannot be closed.
If you need to use night vents to combat condensation, you've got a leak.
If you need to use night vents to combat condensation, you've got a leak.
Hello Catherine,
We need to differentiate between a caravan in storage and a caravan in use. Assuming a caravan is actually watertight, then the biggest source of condensation in an occupied caravan is the occupants breathing (exhaling water vapour) and cooking on the hob (open flames, and boiling water). The raised level of moisture in the air whne the caravan is in use will tend to permeate into the wood and fabrics of the caravan, so when the caravan is put into storage the moisture will be margionally higher and reduce over a few days it will closely approach the natural humidity level of the ambiant air.
During these few days condensation may be apparent on conductive surfaces. and the biological spores may be present and begin the seed for mould growth.
Once the moisture levels have fallen to the ambient humidity level, and provided the correct ventilation is maintained.it is ulikley that condensation will become a major issue, unless there are other sources of moisture such as a water leak into the van.
We need to differentiate between a caravan in storage and a caravan in use. Assuming a caravan is actually watertight, then the biggest source of condensation in an occupied caravan is the occupants breathing (exhaling water vapour) and cooking on the hob (open flames, and boiling water). The raised level of moisture in the air whne the caravan is in use will tend to permeate into the wood and fabrics of the caravan, so when the caravan is put into storage the moisture will be margionally higher and reduce over a few days it will closely approach the natural humidity level of the ambiant air.
During these few days condensation may be apparent on conductive surfaces. and the biological spores may be present and begin the seed for mould growth.
Once the moisture levels have fallen to the ambient humidity level, and provided the correct ventilation is maintained.it is ulikley that condensation will become a major issue, unless there are other sources of moisture such as a water leak into the van.
Hi Roger L and Prof John
As I said in my previous post, our van is kept in a barn, and is completely protected from rain etc. so water ingress is not an issue during storage.
Until we started opening the windows on night latch and cleaning the interior of the van with disinfectant, we did get condensation and mould from time to time in our previous van but only in the winter, when it was laid up for a couple of months. However, it passed all damp tests with flying colours when we came to sell it and that was after a week on our forecourt and in pouring rain.
I also get condensation on the windows inside my car on occasions, when it has not been used for a while, but only given certain weather conditions - never after rain.
If anyone does experience condensation and white powersy mould grwth in their van and has checked for water ingress and none has been found, they might like to try what we have found successful, following advice from both Kelly at Bailey's and others on this forum. It can't do any harm!
As I said in my previous post, our van is kept in a barn, and is completely protected from rain etc. so water ingress is not an issue during storage.
Until we started opening the windows on night latch and cleaning the interior of the van with disinfectant, we did get condensation and mould from time to time in our previous van but only in the winter, when it was laid up for a couple of months. However, it passed all damp tests with flying colours when we came to sell it and that was after a week on our forecourt and in pouring rain.
I also get condensation on the windows inside my car on occasions, when it has not been used for a while, but only given certain weather conditions - never after rain.
If anyone does experience condensation and white powersy mould grwth in their van and has checked for water ingress and none has been found, they might like to try what we have found successful, following advice from both Kelly at Bailey's and others on this forum. It can't do any harm!
Hello again Catherine,
I wasn't contradicting you, but trying to explain the effect you have described, perhaps it needed a bit more detail.
However whilst the the mechanisms involved in producing condensation are the same for both the caravan and the car the circumstances are different:-
Two factors need to be kept in mind, Firstly warm tries to rise over cold, and warm air can carry more moisture than cold.
Caravans are designed to encourage natural circulation of air by having both high and low level fixed ventilation, so a caravan should purge its-self as the warm air can exit through the high level vents being replaced by cooler relatively dryer air.
By comparison, cars rarely have high level fixed ventilation, so any warm (and moist air) will be trapped in the roof area. The large proportion of uninsulated steel and glass which is conductive and will cause the trapped air to cool and deposit its moisture as condensation on the windows(and on the steel, though of course its not so visible).
There are other factors such as asymmetric heating due to sunshine sunlight heating on different sides, and rate of change of temperatures, and wind chill, all of which will affect the rate of evaporation and deposition of condensation etc.
In essence it all comes back to having sufficient ventilation.
I wasn't contradicting you, but trying to explain the effect you have described, perhaps it needed a bit more detail.
However whilst the the mechanisms involved in producing condensation are the same for both the caravan and the car the circumstances are different:-
Two factors need to be kept in mind, Firstly warm tries to rise over cold, and warm air can carry more moisture than cold.
Caravans are designed to encourage natural circulation of air by having both high and low level fixed ventilation, so a caravan should purge its-self as the warm air can exit through the high level vents being replaced by cooler relatively dryer air.
By comparison, cars rarely have high level fixed ventilation, so any warm (and moist air) will be trapped in the roof area. The large proportion of uninsulated steel and glass which is conductive and will cause the trapped air to cool and deposit its moisture as condensation on the windows(and on the steel, though of course its not so visible).
There are other factors such as asymmetric heating due to sunshine sunlight heating on different sides, and rate of change of temperatures, and wind chill, all of which will affect the rate of evaporation and deposition of condensation etc.
In essence it all comes back to having sufficient ventilation.
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