DIY peltier thermo water chiller

Okay ILGM fam I’ve started to tinker with a project that has came up a few times in the threads with @dbrn32 so your tagged lol

I’ve bought all parts through ebay and Amazon and picking up some odds and end at my jobsite.

I wanted to use 2 x 90w-136.8max peltier modules connected to a 12v - 30amp power supply. I have two small heat sinks a 4" square and a 6" rectangle that I combined as I knew going in the my issue most likely would be heat dissipation which I believe to be the issue I have as I’m not getting cold enough temperatures to be an effective application.

Please feel free to comment or tag anyone who may be interested or of help.

I’ve had it set up a few different ways.


I dig it!

So not giving you the amount of cooling you need?

No not at all. Not sure exactly what the issue is but I suspect its heat dissipation and not being able to effectively dissipate the heat from the hot side and I’ll need to end up buying a CPU radiator

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Are you able to measure temps on the hot side heatsinks?

No I don’t have a temp gun not sure why I never picked up one

Those won’t measure the aluminum accurately anyway. Any type of probe probably would though. Can you touch it after being on for a while, or too hot?

Oh one side heats up very quickly you cant touch that without burning you fingers once it’s been on for a few seconds even with the dial on the power supply turned all the down. The other side starts to get really cold but then it only stays moderately cold an unable to cool down temps in water

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Yep, sounds like you’re not cooling enough.

Yeah I even brought home some aluminum fish plates from work to see if I could beef up my heatsink but i think I’ll need a radiator to efficiently dissipate

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I had glanced around, and seems your set up would probably work better for something like a 50 watt plate. Seem about right?

We usually figure around 4 square inches of surface area per watt minimum heatsink for active cooling leds. If that helps any.

Also, what is cfm of fans you’re using and are running them at 12v as well?

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Wouldn’t it be cheaper and help you sleep better at night to just buy the piece of equipment that your trying to duplicate?
Sometimes, it is better to just put out the money for your needs… it’s easy to end up spending more money in the long run trying to cut corners… stepping over a dollar to get to a dime… :wink:
Also that contraption looks and sounds a lil dangerous… just looking out for you… :wink:


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Thx for your input but nothing is inhibiting me for buying one it’s not a money issue of dimes or dollars it just part of a hobby that I enjoy. I assure you this is fairly safe and reliable technology as there is a lot more danger in the lights we use than this diy chiller but thanks for looking out for me


I used to build and compete with computers. I have built a lot of water chillers to keep the computer parts cool so they dont burn up when applying extra voltage. One of my favorites chillers to built was out of an old A.C. unit. lol I would take the condenser and put it in a 6 pack cooler. Attach a thermostat to it and run. I would actually get so cold that i had to use R V antifreeze. But i think with the right thermostat you could control it to the temps you want.


Some pictures on my web page. The frosty picture are liquid nitrogen cooling. But, the one with the water lines are using water chillers.

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I would normally agree with your thoughts. My issue is the amount of power traditional chillers draw, not so much the cost. From someone with my resources, I already have most of the stuff it would take to build one of these, so my curiosity is sparked. It certainly doesn’t appear that it would cost me more than a couple bucks to build something like a 50 watt unit anyways. I’m not entirely sure what a 50 watt unit would do though. My environment would be probably borderline to running hydro without any cooling, so something small like that could make all the difference for me trying something like a small dwc unit.

I do agree that there’s a little more to this than what I would typically tell someone to buy a couple of components and wire up a light. But it’s not much different.


Decide what next step is?

I have some splayed 125mm pin heatsinks that are designed for 100ish watt cobs. Ideally they would cool 50 or so thermal watts passively. I know that they’re also available in 150mm size. The only problem is that most have a minimum order quantity of around 10 units. And they’re not exactly cheap.

Just wondering what you think about possibly giving something like that a try? If you used one sink per unit, and a 140mm pc fan with decent cfm over the top, I think they would have a pretty good chance of working. Just throwing an idea out anyway.