DIY 9-fan roof ventilation for our van
We travel quite a lot in warm areas, so I really wanted some proper ventilation in the van. We didn’t want AC because we’d like to stay off-grid as much as possible, and with 200 W of solar I don’t really see AC as a realistic option anyway.
I also really wanted to keep the original roof hatch because it makes the van so nice and bright. There are some really nice integrated roof fan solutions, but honestly, I didn’t trust myself enough to replace the whole roof hatch. After a previous motorhome had some water ingress, I have a bit of a trauma when it comes to messing with the roof 😂
I looked at various retrofit solutions but couldn’t really find anything that I liked, so I decided to build my own.
It’s basically 9 × 120 mm PC fans, connected to a 60 W PWM controller, with the whole thing mounted in a frame made from L-shaped plastic profiles. I also added a brush strip around the edges to close the gaps and keep mosquitoes out.
The whole thing is powered through the existing 12 V AC preparation that Pössl installed as standard.
The fans are rated at up to ~1,179 m³/h combined airflow, so in theory that’s quite a lot of air for such a small setup.
The nice thing is that I can simply put the whole unit in or take it out whenever I want. I can also turn it around depending on whether I want to blow air into the van or extract hot air.
It just sits on the slightly pulled-in mosquito screen/blackout blind of the roof hatch, so I didn’t have to modify the hatch itself at all.
I’m actually pretty surprised by how well the DIY build turned out. The frame is very solid and the whole thing feels much more like a proper piece of equipment than I initially expected. It’s definitely a bit overkill with nine fans, but that’s kind of the point. 😄
The only thing I’d change is the position of the PWM controller. I mounted it permanently on one side, which makes the controls a little annoying to reach when the fans are facing the other way.
Other than that, I’m really happy with it. No holes in the roof, the original roof hatch stays completely intact, it’s reversible, and I get a ridiculous amount of airflow when needed.
I’ll add a few pictures of the build and installation.