Window Condenstion

From sleeping in the van?


Condensation comes from burning gas-cookers or breathing in the van with inadiquate ventilation.

Unless you have a water leak or other source of moisture in the van.?

So insulation is a side concern.

If you have excessive condensation you need to increase the fresh air flow into the van.
 
'Does sound proofing and insulation help with condensation on the windows' ?
No, keeping the temperature inside the van high enough that the relative humidity stays below 100% helps with avoiding condensation. You could have no insulation but so long as you keep the air warm enough, it won't release its moisture.
Stopping the warm, moist air meeting a cold surface is the best way to avoid condensation.
Insulation will help (as will insulating the windows as they tend to be the hardest part to insulate, ie you can't stick insulation to the windows) but it's a hard won fight.
Any drop in temperature with high humidity means that the amount of water a given volume of air can contain reduces, so it drops out (dewpoint)
Keeping the van just warm enough and getting a through flow of cool, dry air in on one side and letting the warm, moist air out on the other side helps a lot.
Keeping the relative humidity below the 100% line on the psychometric chart is the way to do it.
Psychrometric Chart.jpg
 
As an addendum to this, I was watching a youtube video the other day about a van life couple in Finland, who were adding insulation to their Ducato motorhome.
I have to say I was surprised at the way they had it figured was the right way to do it, since almost every van life video I've seen regarding insulating a van, consisted of packing as much insulation in to the voids as physically possible, where they only put a small thickness of insulation, the wrong way round (ie the insulation comes with a self adhesive backing to make sticking it to the outer skin as easy as possible) and were sticking it to the inside skin instead.
 
With the insulation stuck to the back of the decorative panels then the void between the bodywork and the insulation will be at the external air temperature, surely adding a layer to the inside of the bodywork too will increase the total insulation value giving an intermediate air temperature reducing the potential for condensation to form in the void?
 
My understanding of insulating a van is to reduce the amount of cold surfaces that the warm moist air inside the van can get to as much as possible, the less cold surfaces there are the less chance there is of condensation forming.
I've put two thicknesses of Dodo Thermal Extreme on all the big panels in my van, and then filled the rest with the recycled bottle fleece stuff from B&Q, I plan to add a vapour barrier of reflective bubble insulation once I have finished working inside the voids (running cables/pipes etc) and seal them up as a final step.
 
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