Question: DIY chillers?

Has anyone constructed a DIY chiller of the sort that actually cools the water (vs. just a fan or other means of evaporative cooling)?

Warm weather is still a ways off for me (it snowed today, even though we're almost a month into spring!), but I want to be prepared as this will be my first summer with axolotls.

We have an AC, but I doubt we will want to run it all the time just to cool the tank, and I would like to be able to go away for a couple days here and there without worrying about them getting too hot.

I'm considering buying a used mini-fridge (I have seen them for as low as $25 on local classified ads) and rigging something up with a small pump and a bunch of tubing. I'm thinking of drilling a small hole through the wall or door of the fridge (wherever I can do it without damaging the workings of the fridge), and running airline tubing in and out through it, with several feet coiled around inside the fridge, perhaps in a tray of water for heat exchange), so that water would get sucked out of the tank at a constant slow rate, cooled, and then introduced back into the tank. If I get fancy I may add some sort of thermostat control so that its not running all the time.

Has anyone done anything like this? Or any other DIY chiller?

Thanks!

I should also mention that it can get quite warm where I live - a few days of 40 celcius weather every summer is not unusual, and humidity is quite high, making evaporative cooling less effective.

I'd also love to see other people's ideas on this. I made a thread trying to ask the same thing, actually.

This is my post.

The only chiller that I have seen that is actually safe to make is the one that Skollsunchaser posted. I did some research and apparently its not cheap or safe stuff. It might actually cost you more to make one than to just buy one, and it would be less safe. And I doubt you want to put your hand in some water and get shocked!