I want to build a liquid cooling shirt

[RobertSmalls]

Originally Posted by cfg83

Robert -

Cool cubes! What diameter of vinyl tubing? Pictures?

CarloSW2

Quarter inch. Larger is too uncomfortable to lean on, smaller doesn't fit my pump.

Now that I'm home at last, here's some pics. It's perfectly comfortable to lean on unless two tubes cross (which they didn't before I tore a stitch or two during the 1500mi test trip). Even then, it's fine.



Drove 500mi today with the windows up and no AC on a 85°F partly cloudy day, and stayed comfortable the whole time. When I got home, my water was still icy-cold:



This water-cooled seat cover is my new favorite mod.

[Daox]

How much ice do you think you'll need daily?

BTW, seriously cool mod (no pun intended)

[RobertSmalls]

I used about 25lbs of ice on a very hot day during the 8 hour trip to Indiana, 10lbs on the 6hr trip to Wisconsin (didn't turn the system on until I got to Chicago), 20lbs from Wisconsin to Indiana, and 10lbs from Indiana to Buffalo (85°F, partly cloudy, windows up).

So, uh... a lot, but not a ton.

[cfg83]

Robert -

Most egg-salad. With that data sample I could say ...

lb/hr
25/8 = 3.125
10/6 = 1.667
+ /+
35/14 = 2.5

... that it's very roughly 2.5 lbs per hour. I know I need more data, but it's still neat to crunch.

CarloSW2

[RobertSmalls]

The calculation I used before I built it was:

Driving burns 163Cal/hr, or 189W of metabolic activity. That's the latent heat of fusion of 4.5lbs of ice per hour assuming an insulated cooler and tubes.

Evidently, somewhere between half and a quarter of my cooling came from melting ice.

[Otto]

Nascar drivers use a similar system, with smaller tubes woven into T shirts, etc..

The whole thing works mo better if/when:

1. Wear WHITE or light colored reflective clothing.

2. Cotton and some other fabrics wick better than synthetics, so are more efficient drawing heat away from the body.

3. A WHITE or at least light colored car absorbs much less sunlight and therefore heat than a dark one, so stays cooler. This is especially true of the interior, since a car and its glass are typically a pretty efficient solar oven, when the interior is black or dark.

4. Latent heat of evaporation means that if some of that cool water were leaked or seeped onto the seat cover or your shirt, it would evaporate and make you much cooler than even now. Some guys on a motorcycle website that I frequent do this with a squeeze bulb to pump a bit of water through plastic tubing onto a T shirt. Works great. el cheapo.

5. Google for "evaporative vest" or similar, and see what road and construction crews use to stay cool in the hot sun. The best of these ~$30 vests would of course be white or light colored. They have chemicals in the cloth that absorb water when immersed in water for a few minutes, then evaporatively cool for hours even in the Mohave desert. Similar techniques used in helmet liners, bandanas, wrist bands, etc.. Safety apparel companies sell this stuff online, for cheap.

6. Somebody mentioned "Polar Mesh" reflective and flow-through motorcycle seat covers to prevent monkey butt. Works, but not cheap. Wood bead seat covers do similar, allowing air to circulate between your back and butt and the seat, and reportedly can be had at WallyWorld pretty cheap. Meanwhile, anybody here know where to get "Polar Mesh" or similar cloth to make seat covers with?

7. A combination of these techniques would work synergistically.

[captainslug]

This is as far as I got with mine before I ended up just getting my AC system recharged.

I used vinyl string to tie 4 parallel loops of 1/8"ID 1/4"OD tubing to a sheet of plastic mesh. I was then going to connect them to manifolds to adapt to 1/2" ID tubing.

It's very comfortable to sit on and lean against and if I were to kink any of the tubing, the four parallel loops prevents the flow rate from being affected. Having parallel loops also reduces baseline restriction.

[cfg83]

captainslug -

Very neato. The parallel loops for redundancy and/or pressure relief is a good idea.

CarloSW2