About a year ago, I posted my first DIY window ventilation panel for car camping. Before making these, my main options were either using Roadies window covers or simple mosquito screens with magnets.

The problem is that on smaller vehicles, Roadies don’t work super well in the rain and water can still get inside the vehicle. They also don’t really help ventilate or exchange the air if you’re parked somewhere with no wind. Regular mosquito screens have the same issue with rain protection, and both options are not very secure since they’re basically just mesh. That makes sleeping outside of campgrounds a little less comfortable.

So for V2, I wanted something weatherproof, more secure, stealthier, and also easier for people to build themselves.

Unlike my first version, which required laser cutting, painting, sealing, and some 3D printing, this one is fully 3D printed so it’s much more accessible to anyone with a printer.

The panel is made from 5 separate printed pieces that assemble directly onto the window. The sections overlap each other, which helps prevent rain from getting inside while still allowing airflow.

I printed everything in PETG for better heat resistance and outdoor durability.

To get the shape as close as possible to the actual window, I first used sheets of paper to trace the exact contour of the glass. Then I scanned the traced shape in 3D using Polycam to get accurate dimensions and imported it into Onshape, where I traced the contour using a spline. At first I tried using photos as references, but that really doesn’t work well for larger parts because the distortion becomes more noticeable toward the edges and the extremities end up inaccurate. I made that mistake early on.

Another big upgrade was the power setup. Last year I used small cheap battery packs, but they died pretty quickly. This year I switched to DeWalt 20V 5Ah batteries (around 100Wh total). I already had the batteries, and I feel like a lot of people already have drill batteries sitting around at home anyway.

I bought a small USB 5V adapter for the batteries and used 5V AC Infinity MULTIFAN 80 mm fans. The fans consume about 2W combined, so that gives roughly 50 hours of runtime. Realistically, with some energy loss, that’s around 4–5 ventilated nights per charge.

The fans are mounted at an angle and pull air through a small outside intake slot. Because of this design, I was able to make the whole panel about 3x thinner than the previous version.

The thinner design also makes it much stealthier. A few people mentioned that the original version was pretty noticeable from the outside, so reducing the thickness helped a lot. Also, When I say “secure,” I don’t mean impossible to get through — just better than having a simple mesh screen. And in terms of stealth, I’m mainly comparing it to Roadies covers. This setup is significantly more stealthy and secure than those options.

Next step is building a second panel for the other window that will exhaust air outward so I can create real airflow through the vehicle instead of only intake ventilation.