Insulation Won’t Save Your Van (Do You Actually Need a Roof Fan?)

You can spend hours going down the rabbit hole on insulation.

Foil board, wool, foam… trying to get it perfect so your van stays “cool in summer and warm in winter”.. like everyone claims. And don’t get me wrong, you absolutely should. Insulation matters.

But there’s something I didn’t fully appreciate until I’d spent real time in vans.

Insulation on its own doesn’t make a van comfortable. Not even close.

I remember helping a mate out in their van one hot day. Fully insulated, done properly. We were just looking over their battery setup and after about 20 minutes I was absolutely dripping in sweat. It had basically turned into a hot tin can.

At the time I didn’t think much of it, I just knew I needed to get out before I started dripping sweat on their bed. I got out of there and went back to my own van where I’d left the roof fan running.

The difference was honestly rediculous. Still warm (of course), but actually manageable. Comfortable enough to sit in without feeling like you needed to escape.

That was the moment it really clicked for me. The difference wasn’t insulation… it was airflow.

The way I think about it now is insulation and ventilation are doing two halves of the same job. Insulation slows down how quickly the outside temperature affects your van. That’s it. It doesn’t stop heat getting in, it delays it.

And in a van, there’s only so much delaying you can do. Eventually, that heat gets in and just sits there. Without any airflow, it builds up and you feel it.

That’s where a roof fan completely changes things. It’s not a miracle worker, your van’s not suddenly air-conditioned, but it keeps air moving. It’s constantly pulling that hottest air out from the ceiling and bringing fresh air in. And that small bit of movement makes a bigger difference than people expect.

But the biggest benefit of a roof fan isn’t even the heat… it’s moisture.

If you’ve ever slept in a tent or even your car, you’ll know how much condensation builds up overnight just from your breath. It’s a lot. Now imagine that happening inside your walls or ceiling where you can’t see it.

That’s where you start getting mould, water damage… the stuff that quietly ruins a build from the inside out.

Even on nights where it’s not hot, I’ll still run the fan. Just to keep some airflow through the van and push that moisture out before it has a chance to settle anywhere.

That’s the part most people don’t think about when they’re planning their build. They’re focused on keeping heat out, but not on what’s happening to the air inside the van once you’re living in it.

So do you need a roof fan?

You can build a van without one. Plenty of people do.

But if you’ve gone to the effort of insulating properly, and you actually want the van to be comfortable to live in, not just look good when it’s finished… it’s one of those things you’ll end up wishing you did.

For me, it’s one of the few things I’d still prioritise even on a budget build. It just makes that much difference day to day.

If you’re at the stage of planning your setup, I’ve linked the fan I use in my own builds below. It’s the one I use because it solves these problems properly. There are cheaper options out there, but this is the one I trust when it comes to heat and moisture control.

👇Check it out here (affiliate - thanks for supporting the channel!)
https://www.journeyvanbuilds.com/maxx-air/affiliate

🔥Use discount code “Journey5” for 5% off your order at OutbackEquipment 🔥

If you take anything from this, it’s this:

Insulation slows things down… but airflow is what actually makes your van livable.
And once you’ve experienced the difference, you won’t go back.

Thanks for reading! I’ll catch you on the next one,

Jake