Ventilation is one of those things almost nobody thinks about when converting a van, until the problems show up: condensation on the windows, smells that won't go away, unbearable heat in summer, or that stuffy air when you wake up. Good ventilation solves all three at once, and it's neither expensive nor complicated. The key is understanding one simple idea: ventilating means creating a flow — air coming in one way and going out another.
Why you need to ventilate (even when it's cold)
Inside the van you constantly generate moisture: from breathing, cooking, drying clothes. If that damp air doesn't get out, it condenses on cold surfaces and damp and mould appear. Plus, in a closed space the air gets stale. That's why ventilating isn't optional: it's about health and comfort. And the better insulated and more airtight the van is, the more it matters. We connect this with condensation.
The skylight: the star piece
A skylight (roof window) is the most effective ventilation element, because hot, damp air rises and naturally escapes through the top. Some are simple (they just open) and others come with a built-in fan, which forces air extraction or intake. A skylight with a roof fan is probably the best ventilation investment you can make.
Creating a flow: intake and outlet
A single opening barely ventilates; what actually works is creating a current. The winning combination:
- A fresh air intake down low or through a side window.
- A hot air outlet up high, through the skylight (better with an extractor fan).
That way fresh air comes in, moves through the van, and hot, damp air goes out. In summer it greatly reduces the feeling of heat; in winter it removes moisture without over-cooling.
Vents and permanent ventilation
Besides the openings you open and close, it's worth having some permanent ventilation (vents), especially if you use heating or a combustion stove. They renew the air little by little without you having to think about it, and they're a safety measure against gas build-up.
Don't forget the mattress
A point many people overlook: moisture you give off while sleeping builds up under the mattress. Fitting a separating grid or slats that let air circulate underneath prevents that dampness and extends the mattress's life. Airing it out from time to time helps too.
In summary
Ventilating well means creating an airflow (fresh air in low, hot air out high through a skylight, ideally with a fan) and keeping some permanent ventilation going. The step you can take today: if you're only going to make one ventilation upgrade, make it a skylight with a roof fan; it's what changes summer comfort the most and what cuts winter condensation the most.
