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Water-Cooled Jacket

I've been scheming about personal water-cooling systems every summer for years. As heat waves here now regularly slide into the 30-35°C zone and air conditioning is still mostly an un-heard-of and un-affordable luxury, I finally decided to see what I could make.

Photo from the front, showing the pattern of colourful stitching holding the pipes.

Photo from the back, showing more stitching and a zig-zag of faintly visible shapes of pipe.

Assembly

The idea is really simple:

make a light-weight jacket
sew flexible pipes into it
pump cold water around the pipes

My solution to the pump is a 3D printed peristaltic pump, based on a design by Drmn4ea from Thingiverse, which itself was based on an earlier design for a printable planetary gearbox.

https://www.thingiverse.com/thing:454702

I adapted the pump to fit the pipe I had and added a hand crank and top/bottom cover pieces.

OpenSCAD model (I wouldn't recommend trying to print this mess to be honest)

The pipes are a one metre length of silicone tube through the pump, because it has to be very flexible, and 10 metres of PVC of the same diameter inside the jacket. The two are coupled by a one-way valve to take some load off of the slightly weak pump.

My answer to the jacket was to re-use fabric from taking an old shirt to pieces. I traced the shape of a simple top that I like, and used that to sketch out a pattern and approximately replicate it. There are then strips of fabric sewn into the jacket with spaces left to thread pipes through. This holds the PVC pipe tightly against the wearer.

For the moment, I've just shoved the ends of the pipe through the top of a plastic bottle. This acts as a coolant reservoir.

Photo of the inside, showing off all of the pipes winding through five strips sewn into the jacket.

Thoughts

It works! I'm mildly amazed, frankly.

You have to crank quite a bit to cycle all of the coolant, so I'm curious to see if it's actually effective in high temperatures. I think the coolant would need to pretty cold, but a bottle of water with some ice in seems like it should do the trick.

Things I discovered while building the whole thing:

I wildly underestimated how long the sewing would take, it must have taken on the order of 10 hours! (this was my first big sewing project)
I'd quite like a Victorian-style hand crank sewing machine (the motor drive on ours doesn't provide enough control)
PVC pipe is actually fairly inflexible, which messed up how the jacket hangs a bit