Theories Are Hurting My Head :)

[Trogman]

Since checking the caravan with my own damp meter i have some high readings under one of the front windows, this has obviously led me to investigate.

 

The readings lower some directly under the window, however as i take readings heading toward the shelf that divides the front locker from the van they get higher. So my attention turned to the ceiling in the front locker which shows signs of damp, from the middle window on-wards its bone dry.

 

When i run my fingers across the top edge ( in the front locker) there is some water residue sitting on a small ledge. this would be the side of the wall which is in contact with the front panel of the van.

 

Its definitely not the window seal nor is the grab rail leaking has anybody got any ideas ?

 

My Brain is fried!

[Guest]

In a word - condensation.

Cold outside, warmer (if only slightly) inside, then any moisture in the air is likely to consense on the inside face of any exterior wall including any inside a locker.

Gordon.

[Trogman]

anything i can do ?

 

thanks

[Cvan1]

Sleep with the windows on the night latch. ..

[Black Grouse]

Sleep with the windows on the night latch. ..

I've heard that advice sooooo many times - but why? I've never had to in several decades of caravanning, unless it's a heatwave - caravans do have fixed ventilation which should be adequate.

[xtrailman]

I would put a hair dryer onto the area, if its condensation the damp readings should drop.

 

We rarely leave windows on vent but its required sometimes if condensation becomes a problem.

We open to vent or wider when cooking and showering.

 

At home we have to go round all our windows to clean up condensation as its a bungalow and we sleep with windows shut, also use a couple of dehumidifiers as required.

[kirkcaravanservice]

Try leaving the problem locker doors open after you have dried up the water to see if the problem persists as this should keep the inside of the locker at the same temp as the inside of the van,

 

You breath out a lot of moisture so leaving the windows open on the night catch allows it to escape more easily.

[Guest]

There are only two options. Either do not produce dampness in the air, or if you do, allow a way for it to escape.

To minimise the humidity, do not cook or boil a kettle without at least opening the skylight, and do not use the shower late at night.

To remove the vapour from your breath, leave a window or two on a night latch overnight (it doesn't have to be right next to your bed) as this will encourage fresh air circulation via the installed vents.

Gordon

 

anything i can do ?

 

thanks

[CommanderDave]

You also have to consider that a caravan has a framework inside the walls that the water can track along and leaks and damp signs can be a distance apart. If the caravan cupboards are left open and allowed to circulate the air it should be fine . From my experience any rise in moisture usually means a leak somewhere.




If you apply heat in the caravan it will cause condensation



Dave

[rolywak]

All this leads me to my own thoughts !

Recently, prior to use, I heated my caravan with the fire.(Truma 3002 ) on gas.

I then had damp ( water ! ) in the rear corners.

We then used the caravan for five nights, using the 1 KW electric controlled by a thermostat at about 18 deg.

No water did I see.

Getting home it stood for a day, and on the next day I heated it with the gas fire.

It then showed some damp.

I put an electric convector fire in it, set at 5 deg . No damp.

What is the difference ?

[Trogman]

You also have to consider that a caravan has a framework inside the walls that the water can track along and leaks and damp signs can be a distance apart. If the caravan cupboards are left open and allowed to circulate the air it should be fine . From my experience any raise in moisture usually means a leak somewhere.

 

 

 

 

If you apply heat in the caravan it will cause condensation

 

 

 

Dave

I would of agreed with that there was a leak somewhere before posting the topic, however from investigating further i am 99. 9 % sure that there is no leak.

I have since sprayed some water on the inside of the window to try and replicate condensation, and i tracked the path of the water and kind of come to the conclusion that this maybe the cause. If this is not i really am lost as to what could be causing the issue.

I have left a number of windows on vent to try and balance the temperatures, this should be confirmed with dropping damp readings.

 

It just puzzles me how this could happen in one particular area of the van.

[bspks]

All this leads me to my own thoughts !

Recently, prior to use, I heated my caravan with the fire.(Truma 3002 ) on gas.

I then had damp ( water ! ) in the rear corners.

We then used the caravan for five nights, using the 1 KW electric controlled by a thermostat at about 18 deg.

No water did I see.

Getting home it stood for a day, and on the next day I heated it with the gas fire.

It then showed some damp.

I put an electric convector fire in it, set at 5 deg . No damp.

What is the difference ?

 

There shouldn't be any difference.

If the caravan has been properly serviced and the Truma heater correctly checked the flame burns in a sealed heat exchanger using outside air, and the outside of the sealed heat exchanger heats the caravan air which should be no different (apart from more powerful) to the electric element.

If using gas is producing moisture, the I would be concerned that the heat exchanger may be faulty causing the flame to burn in the caravan air.

This is potentially dangerous, and I would get it checked before using it further.

There is a safer possibilty, it may just be that using the 3. 4kW gas heater heats the air that much quicker than the 2kW electric elemnt which might cause more condensation at start up.

[DeeTee]

All this leads me to my own thoughts !

Recently, prior to use, I heated my caravan with the fire.(Truma 3002 ) on gas.

I then had damp ( water ! ) in the rear corners.

We then used the caravan for five nights, using the 1 KW electric controlled by a thermostat at about 18 deg.

No water did I see.

Getting home it stood for a day, and on the next day I heated it with the gas fire.

It then showed some damp.

I put an electric convector fire in it, set at 5 deg . No damp.

What is the difference ?

There is probably no difference and certainly not significant enough to be concerned about at this time of year. In my opinion you would need to have temperature and humidity readings before drawing any meaningful conclusions.

 

Damp caused by condensation can be managed by appropriate ventilation but damp caused by a leak is a different matter.

 

Between outings my caravan is in storage 130 miles away from my home, as it has been for ten or more years, so I am unable to heat the caravan prior to using it even I wanted to do so. On arriving on site at any time of year I only put the heating on after setting up when I also open the roof light for a short time. In use the caravan is never hermetically sealed as I always ensure a flow of air through it depending on conditions and time of year. After cooking Christmas dinner it is not unknown for a window to be opened The result for my caravan is no condensation and no damp.

[Guest]

Getting home it stood for a day, and on the next day I heated it with the gas fire.

It then showed some damp.

 

I put an electric convector fire in it, set at 5 deg . No damp.

What is the difference ?

In the days when gas heaters burnt an open flame within the caravan, this would make sense as water vapour is produced when burning gas, but for many years now all flames have been contained in an enclosure vented only to the outside world, and so there should be no difference with either heat source, apart from a difference in power.

Gordon.

[Towtug]

If you use bottled gas for cooking or with a gas fire it produces alot of moisture. From memory 6hrs use produces about 2 litres of water. If you then have cold surfaces (or large temperature differentials) this moisture will translate to the colder surface. This is why you often get condensation forming at the bottom of a wardrobe for example.

[Guest]

If you use bottled gas for cooking or with a gas fire it produces alot of moisture.

Very true if the gas flame were inside the caravan, such as when using the gas cooker, but my understanding is that the OP's problem relates to the space heater, and fumes from this should be totally isolated from the caravan interior.

Gordon.

[Steamdrivenandy]

Condensation is moisture held in suspension in the air condensing on a cold surface, because the colder the air the less moisture it will hold.
There are two ways to stop water condensing on cool surfaces, one is ventilation to reduce the amount of moisture in the air and the other is heat which increases the airs capacity to hold moisture and warms the cool surfaces.
Ventilation can be a problem as it can introduce more cold air, which makes it harder to increase warmth. Also on damp days you might be letting in air that is just as damp as that which is inside already. Having said that there are so many airholes in a van that apart from specific events like cooking and showering the moisture content of the air in a vans interior is normally the same as outside.
There is always a chance of condensation when initially warming a van because surfaces are cold and take longer to warm than the air inside the van. Some surfaces, because of their proximity to outside, may always remain cold and therefore risk condensation, even if the van has been warm and dry for days.

[rolywak]

Very true if the gas flame were inside the caravan, such as when using the gas cooker, but my understanding is that the OP's problem relates to the space heater, and fumes from this should be totally isolated from the caravan interior.

Gordon.

And a CO detector is usually in the caravan, when in use !

[Black Grouse]

And a CO detector is usually in the caravan, when in use !

Water vapour due to combustion is different from CO or CO2.

[kirkcaravanservice]

Complete combustion should only give out carbon dioxide and water vapour (also what you breath out) incomplete combustion gives out carbon monoxide which is the killer you don't want. But as said the 3002 fire is room sealed and should produce nothing other than heat to the inside of the caravan. Also as said you can create condensation by turning on the heating but it's only surface water and should start to dry up fairly quickly and should be no threat of causing dampness to a caravan.

[xtrailman]

All this leads me to my own thoughts !

Recently, prior to use, I heated my caravan with the fire.(Truma 3002 ) on gas.

I then had damp ( water ! ) in the rear corners.

We then used the caravan for five nights, using the 1 KW electric controlled by a thermostat at about 18 deg.

No water did I see.

Getting home it stood for a day, and on the next day I heated it with the gas fire.

It then showed some damp.

I put an electric convector fire in it, set at 5 deg . No damp.

What is the difference ?

A electric fan heater will give movement of air.

 

When I had a home condensation problem in the bathroom I brought a damp expert in.

His advice was to install an "all house air ventilation system" to REDUCE the condensation.

 

He repeatedly said "movement of air", I got the message.

[xtrailman]

Condensation is moisture held in suspension in the air condensing on a cold surface, because the colder the air the less moisture it will hold.

There are two ways to stop water condensing on cool surfaces, one is ventilation to reduce the amount of moisture in the air and the other is heat which increases the airs capacity to hold moisture and warms the cool surfaces.

Ventilation can be a problem as it can introduce more cold air, which makes it harder to increase warmth. Also on damp days you might be letting in air that is just as damp as that which is inside already. Having said that there are so many airholes in a van that apart from specific events like cooking and showering the moisture content of the air in a vans interior is normally the same as outside.

There is always a chance of condensation when initially warming a van because surfaces are cold and take longer to warm than the air inside the van. Some surfaces, because of their proximity to outside, may always remain cold and therefore risk condensation, even if the van has been warm and dry for days.

at home I have a couple of weather stations bought from Aldi or Netto years ago.

With them I can see the temperature and humidity in different rooms and outside.

 

In a morning during winter we check the bedroom humidity and this determines if the dehumidifier goes on or not.

[ian16527]

Since checking the caravan with my own damp meter i have some high readings under one of the front windows, this has obviously led me to investigate.

 

The readings lower some directly under the window, however as i take readings heading toward the shelf that divides the front locker from the van they get higher. So my attention turned to the ceiling in the front locker which shows signs of damp, from the middle window on-wards its bone dry.

 

When i run my fingers across the top edge ( in the front locker) there is some water residue sitting on a small ledge. this would be the side of the wall which is in contact with the front panel of the van.

 

Its definitely not the window seal nor is the grab rail leaking has anybody got any ideas ?

 

My Brain is fried!

I dont know how old your van is, but on my last Elddis van, it had a chipboard type length of material, in the front locker below the front window. My van leaked from the join at the roof to front panel and this board would be always wet as the water travelled down one side past the window.

 

As the front lockers are well vented, I would be suprised if the water at the top edge is condensation as this area should be at an even temperature, as as said previously, its the warn air hitting a cold surface which gives rise to the water.

[rolywak]

A electric fan heater will give movement of air.

 

When I had a home condensation problem in the bathroom I brought a damp expert in.

His advice was to install an "all house air ventilation system" to REDUCE the condensation.

 

He repeatedly said "movement of air", I got the message.

 

So if I use the 'blow-air' instead of just the fire, it should reduce the condensation ?

[Black Grouse]

Why does condensation only affect some caravans, or some people - the fixed ventilation that every caravan has will cope with moisture from exhaled breath from people, but perhaps not from wet dogs, and cooking/showering just needs the roof vents open for short periods - so if it's not "water ingress" just where is the moisture coming from?

 

It can't be ambient moisture as that would affect every caravan, which it clearly doesn't.