Condensation

[NickinFrance]

We seem to have a bad dose of condensation on & around the rear shower room window in our 2006 Sterling Europa.
I originally thought it was because of where we stored the van with that end facing North with no protection or wind break for 50 yds or so but we moved it over the week-end to a more sheltered spot & I noticed this morning that there was some moisture on the window.
I have been drying the the shower room out for the past week with a heater (set to 19º) & about 20, 500 g bags of Silica Gel which has dried the surface moisture out of the wood.
I don't really want to keep the heater running all winter, so has anyone advise on how I might prevent this condensation forming in the future.

 

[kennygee]

I always use the crystals that you can buy from the dealers. I have 4 or 5 spread about the van

 

[NickinFrance]

Thanks for your reply, I think it might need more that a few bags of crystals, which I assume are Silica Gel.
This is what I found a couple of mornings ago:

 

[Rita1]

1st Are you sure there is no leak or rain being blown through

2nd I see you have not vented the window Air is the best thing to keep condensation away

3rd To be honest the crystals are a waste of money But if you think they help then go ahead

 

[NickinFrance]

Thanks for your reply

1st Are you sure there is no leak or rain being blown through

Unless the window is porous, I'm pretty sure. There is no trace of water anywhere else apart from that bottom corner

2nd I see you have not vented the window Air is the best thing to keep condensation away

I did leave it open on the vent latch position last winter & that's when I first noticed the problem, in fact because of the exposed site I thought it was rain that had blown in.

3rd To be honest the crystals are a waste of money But if you think they help then go ahead

I've already got 25 kg of Silica Gel & it does seem to help in drawing the surface moisture out of the wood but not sure they would help in the long term.

 

[Dustydog]

Nick

Are you sure it's condensation?

Open the window as wide as possible. Now thoroughly clean the top rubber seal joint between the window and frame. I had loads of dirt and moss that was letting water, moisture, into the caravan.

Hope it sorts it for you.

 

[NickinFrance]

Dusty, I'm pretty sure that it is condensation.
There was some vertical movement on the window which I initially thought might have been the problem but I removed the window & tightened the slit in the top rail to stop that movement but there was still moisture after I did that.
I've had a heater on, with bags of Silica Gel & the roof vent open for a couple of nights & there was no sign of moisture this morning.

 

[ProfJohnL]

The root cause of condensation is warm moist air coming into contact with a cold surface. Factors that influence it include the fact that warm air can carry more moisture than cold air. Humans and other animals all breath out warm moist air, and any open gas flame produces moisture, so a caravan which has relatively thin windows and aluminium fittings will cool down. Any warm air in contact with the surface will also cool down and that causes the air to condense out some moisture depositing as condensation. This is why occupied caravans do develop condensation.

Due to the requirement for caravans to have fixed ventilation, attempting to dry out the air in the caravan by using crystals or even a dehumidifier is a waste of money, as the dried air simply passes out of the caravan to be replaced by moister air from outside.

Dehumidifiers are useful in helping to remove excess water caused by a leak, but the proper solution is to cure the leak first.

Controlling normal condensation is ventilation.

 

[NickinFrance]

Thanks, I did realise what causes condensation but was concerned why it only formed at that one window.
I guess it was a combination of, the direction & lack of any weather protection of that end of the caravan & there being no ventilation in the washroom.
I've now moved the caravan to a more sheltered spot in the garden & opened the roof vent in the washroom, so will see how it goes over the next few (wet) days.

 

[ValA.]

Are you absolutely sure there's not more evidence of damp in that area? The two screw holes show rust marks, indicating that the screws at that point have been wet or rusted, there's just the faintest 'possible damp bubble' to the bottom of the picture under the window handle, at a point where the water drip shows on the handle, and the 'joint' of the window strip is just above the area where the screw holes show rust. The water 'drip' on the window handle, shouldn't be the result of 'condensation' as the handle wouldn't be a 'cold surface' (as the above definition) normally and looks more like rain ingress from somewhere.

Have you tested the area with a damp meter, or looked at the outside seals above the window for possible 'seal failure' or other signs of water ingress. I must admit that would be the first thing I would be looking for rather than just putting it down to condensation.

 

[NickinFrance]

I didn't know what the cause was originally, so asked on the Swift Forum & the consensus there was that it was condensation.
I have removed the rubber seal & the only sign of damp on the battening is along the bottom of the window for about a third of it's length & up the left side for about half it's height.
I have slipped a sheet of blotting paper between the outer ABS skin & the battening & it was only damp for the top 5" - 6"
The caravan was parked with that side down slightly.
The drip on the handle is actually on the window.

 

[terence1]

nick,you seem to have the same problem that i had with my 2004 swift challenge [if it is the same type of fittment]
that is your window seal has failed at the caravan side and is allowing water to creep in between the seal and the caravan.

the water is getting in,running down the chanel and creeping in at the bottom and that is what you are seeing.
my cure was to take out the seal completely,...clean it [and the slot where it fits into],
smear silicone grease on the seal and the slot on the caravan and reinstall the seal , that should cure it,...it did for me.
hope this helps