Liquid cooling vest help - RC-Monster Forums

C-5Quad · **Liquid cooling vest help -** 04.30.2011, 10:11 PM

I'm a quadriplegic and my body can no longer regulate my temps by sweating and as a result. I can not tolarate the summer heat for any long periods. So I'm building a liquid cooling vest. I'm using 1/4 in thin wall tubing sewn into a vest in several rows like a radiator and plan on using a 12v brushless water pump to circulate ice water from a small cooler mounted to the back of my powerchair to my vest to keep me cool.

my question is what can i use to adjust the pump speed to where I need it as I'm sure I wont need it going all out all the time. I'm thinking some sort of voltage regulator to use like a gain on an amp but don't know where to find one.

I want to be able to run the pump in cycles as i dont want it running non stop

the pump I'll be using
http://cgi.ebay.com/ws/eBayISAPI.dll...2882&viewitem=

any help would be great.

BrianG · 04.30.2011, 10:25 PM

First of all, be careful with the temp adjustment. Even though it may feel good, setting it too low could cause hypothermia. Similar to how you have to heat a waterbed.

Second: Using a voltage regulator for a pump is quite inefficient. When set to low, the regulator will generate quite a bit of heat. Also, note that the pump may not start up if the voltage is too low - this will take some experimenting to figure out. But if that's still something you want to do, a simple LM317T adjustable regulator with a pass transistor can be cheaply made. The sample circuit can be found in the LM317T datasheet.

A better solution is a PWM fan controller. Many computer fan speed control modules use this method. Just have to find one that is rated for ~1A. Heck, you could even rig an ESC to do it, but would be more expensive and convoluted.

C-5Quad · 04.30.2011, 10:35 PM

so this would work?
http://cgi.ebay.com/12v-PWM-PC-Muffi...item563d7254a7

its rated 6 amps

sikeston34m · 11:27 PM

6 amps isn't very much. Especially when considering start-up loads.

It just might work though, since the motor specs state that it only pull 840MA

Hook it up to a thermistor. (works like a thermostat)

Put the thermistor between the jacket and you.

If you find a fancy thermistor, it will be adjustable.

This will cycle the pump off and on so you will stay in your confort zone.

I hope this helps.

Best of luck.

What's_nitro? · 04.30.2011, 11:30 PM

That controller should be powerful enough for a 10W pump. You would need the thermistor to turn on a relay, or large transistor, that then would send power to the PWM controller. The speed of the pump would be independently adjustable from the temperature control.

_paralyzed_ · 05.01.2011, 04:05 PM

I've been dealing with this for 10 summers now. The best way I've found to keep cool is hydrate hydrate hydrate, and more hydration.

Short shorts and thin shirts. Also critical is misting water on any exposed skin including legs. Evaporation has a cooling effect. (why you get cold when toweling off after a shower) My mom always buys me those novelty misters with the fan on top.

I like where your head is at in trying to use technology to solve your problem. It could also be easily adapted to be a warming vest.

But don't forget the tried and true methods: replacing your body's sweat with misted water. Like every couple of minutes. It has helped me to tolerate a lot of heated situations. Good luck!

_paralyzed_ · 05.01.2011, 05:13 PM

whatever tank you use could have a fish tank heater installed to warm in winter.....

C-5Quad · 11:38 AM

I use a small hand held pump up sprayer from lows to mist myself now. Since my hands don’t work it is far easier for me to use and it was only $8.00. It works great but, I want a system that I can stay cool and dry. I plan on doing a lot of fishing this summer and I usually wear white long sleeves and a big brim hat.
I plan on trying two ways. The first will be a vest the second just a back rest cover like a hospital cooling mat. I hope the back rest works well so I am not attached to the system.

whitrzac · 05.02.2011, 11:51 AM

look into water cooling setups for PC... Most of the modern ones use larger hose, but it should be fairly easy to adapt them, and they run on 12v.

a pump+small reservoir+a radiator would set you back $100ish

examples, stuff can usually be found for less
http://www.frozencpu.com/cat/l1/g30/...ml?id=xrRkp7Eq

BrianG · 05.02.2011, 12:23 PM

Have we considered something more simple? maybe something like a large finned heatsink (maybe even fan cooled) as a back rest with a gel-pack of some kind to act as cushion, yet transfer heat to the heatsink. Would be a lot simpler I would think...

sikeston34m · 05.02.2011, 07:26 PM

Quote:

Originally Posted by BrianG

Have we considered something more simple? maybe something like a large finned heatsink (maybe even fan cooled) as a back rest with a gel-pack of some kind to act as cushion, yet transfer heat to the heatsink. Would be a lot simpler I would think...

What?

FAN Cooled?!!!

LOL

BrianG · 05.02.2011, 07:34 PM

Note that I said "maybe even fan cooled" and in parenthesis.

The only reason I bring this up is because one time several years ago, I was lying in bed trying to read a book and it was really hot (AC was broken). I happened to have a large heatsink plate laying around (who doesn't, right?) and just set it on my chest/belly. It really made a big difference. Yeah, it was odd, but it worked surprisingly well.

What's_nitro? · 09:39 PM

Quote:

Originally Posted by BrianG

The only reason I bring this up is because one time several years ago, I was lying in bed trying to read a book and it was really hot (AC was broken). I happened to have a large heatsink plate laying around (who doesn't, right?) and just set it on my chest/belly. It really made a big difference. Yeah, it was odd, but it worked surprisingly well.

I literally

'ed at the vision of a guy laying in bed with a giant heatsink on their stomach reading a book...

It made me think of this-

In case you're wondering, I do, in fact, have a large heatsink in my "heatsink bin" that would serve that purpose well.

_paralyzed_ · 05.02.2011, 09:54 PM

yeah, the getting wet sucks

I think you have a good idea. I'd like to make a pressure relief air cushion with pressure varying pockets. Just like a pressure relief air bed but in seat cushion form. I think that would help keep me off bedrest.

C-5Quad · 07.29.2011, 01:09 PM

ok update time...the vest is done and works great on 3s. outside temp was 96f and body temp was 98.7f after 1 hour body temp was stable at 97.4. water was 48 going in and 65 exiting the vest. 1 8x3x6 inch block of ice lasted over an hour with constant flow. the pump used 928 mah in 1.25 hours on a 3s 5000 45-90c nano tech.

ok now I need help to build a 3 position cycling switch that will turn on the pump for 5 minutes then off for 3 min and repeat with a stay on option as well.

so the switch will be

stay on
cycle
off

any help would be great as I have no clue how to build a cycling switch. I looked into thermistors but could not find an ajustible 12v system that works in the temp range I need that was affordable.