Condensation occurs when warm air inside the campervan comes into contact with a colder surface, such as the van windows or the pop top tent walls or roof. Air temperature in the camper can become warm and humid from people, heaters, and a lack of ventilation.
When the warm air inside the van hits the relatively cool fabric of the pop top tent, the van windows, or even the side walls of the van if there isn’t good enough insulation behind them in the cavities, the moisture condenses into liquid form.
One person can exhale up to 1 pint of water overnight, and this water vapour converts to liquid when it meets the colder surfaces of your campervan or pop top roof tent. Furthermore, if there are multiple people and pets sleeping in the van, the amount of water in the air increases considerably and condensation can be so much that it’s easily and often mistaken for a leak.
Here is a link to an interesting article by Vango explaining the problems with condensation inside tents, which is basically exactly the same as you will experience with a campervan.
Basically… yes. Campervans designed with good ventilation and good insulation will fair best. In certain weather conditions, the design of any van can be overwhelmed by moisture. For example, if it is a cold night and there is no breeze to circulate the warm, moist air out of the campervan, condensation is likely to form.
We hope this information helps you control the condensation in your campervan a bit better so your camping trips are more enjoyable and less of a worry.