My water bucket and inline radiator was working great for the winter but as the warmer weather came in even with the AC running i was getting higher temps that i wasn't too happy with. So i started digging around eBay and came across a STEAL of a deal!



There is a seller on eBay with a whole pile of these things, its a ThermoTek T252P thermoelectric chiller. It uses 10 45w Peltier's inside, i found a few mentions of these on another forum but i haven't been able to find much info on these otherwise. The seller i bought mine from is CTR Surplus, but if you search for ThermoTek T252P you will find them. They have a bunch of them listed for $74.95 or best offer, i made an offer of $50 on one that was listed as powering up and working but the air dryer doesn't work. It has two sets of fittings on the side, water in and out and air in and out, the air side apparently can be used to dehumidify. The only problem with this one seems to be the fan for the air dryer side isn't working, could fix it with a $10 fan but since i don't need the air dryer side who cares!!

The water side on this one works great, i ended up setting it to 18C and it keeps the laser around 64-65 degrees while cutting under full power. I ran about two hours on cutting and the water temp coming out of the tube never got over 68 degrees. As for the pump in it, its got a better pump then any of the pond pumps i tried in my bucket cooling system. It will empty the reservoir in less then a second when the pump kicks in. It has a low coolant shutdown and displays Check Fluid on the display, i had to pulse it on and off a few times while filling the reservoir to get it keep circulating, then i worked the air out of the system and topped it off.

Another really nice feature is the water fittings are valved CPC fittings, so you can disconnect the coolant lines and not loose and coolant or get any air into the laser tube if you need to move stuff around. Also makes it easy to flush the system by plugging a drain tube into the output port and just use a larger container and a funnel to keep filling the reservoir as it pumps through the system. I run a mix of RV antifreeze and distilled water, in testing this unit before installing it on the laser i made a loop of tubing and plugged it into the unit to flush and fill it and run it to circulate a while, by the smell of the reservoir it was running straight glycol in it. It WILL get down below freezing, i ran straight RV antifreeze in it and dipped a loop of tubing into a bucket of water and it started freezing the water to the outside of the loop.

For the cost of these i might buy another one for other uses and to keep on hand as a spare, beats a $1500 water chiller in my book. You can also find these tested and working in good shape on eBay for around $250-300 if you don't want to buy a potential fixer upper, but for what CTR is selling them for if you got one with bad Peltier's or some small issue you could easily rebuild it.