Poor Mans Water chiller

I have tried several low cost methods to keep my cooling water on my 50 watt laser at an acceptable level, but finally seemed to have found something that works. I have seen variations of this but not this exact method.

I took an old cooler/ice chest that was laying around and drilled two holes in one end at the top just large enough to get the cooling tubing through each hole.
A coil of tubing (I think its about 50 ft) was placed in the cooler and the ends brought out of the two holes.
The return water from the laser tube was then connected to one end and the other end is sent back to tank after running through the coil in the cooler. The cooler is filled with water an inch or so below the holes.
Before I start to use the laser I place several freeze pacs in the water to chill it down.

Google Photos

I’ve used this the past few days running some cuts at about 65% (which is not too far away from the max power point for this machine. The laser cut about 15 to 20 minutes at a time for several cycles and the water never got above 20c. A huge improvement over what it was doing before.
If more cooling is required it could be accomplished by adding more tubing inside the cooler, or better yet, change the tubing in the cooler to a larger size to slow the velocity of the water allowing it more time in the chilled water.

Better solution. Pick up an under counter mini fridge and put an aluminum tank inside. I have a rough prototype in use with my 80W. It’s a little on the wimpy side for the 80W because the tank is too small. Going to make a custom tank to double my water capacity. Should be good after that.

$116 for an entry level chiller. The biggest single factor to consider is the advantage of a closed loop / sealed chiller. That is, the closed system and use of distilled water prevents algae as well as contamination / impurities.

The CW3000/CR3000 will only cool to ambient temperature.

You’re right about that. I found many of the “chillers” actually didn’t “chill” at all. They are mainly radiators. You had to get up to the 500.00 price point to start getting into true chillers.

My tank in the fridge has a lid, and a few drops of aquarium algaecide takes care of that. A few drops of Dawn keeps everything clean. Had the same water in for almost a year with no sign of any problems.

Best part is, since the laser is out in the shed, I have room for a few beverages beside the chiller tank! It drops the tank temp to around 30F to 40F below ambient. I do need to make a custom tank though, the only bucket I had that would fit is a bit small so I don’t have as much thermal mass as I’d like.

This is mine. 3/8" x 25’ copper coil on return side and 3/8’ x 8’ coil on inlet side. Both are tucked inside the bucket. Been using this for approx. 16 months. Have changed the regular tap water twice. Probably change again soon.

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A cheap condensing chiller is an aquarium chiller or a brewers chiller - US$250ish.

You see a lot of AC and dehumidifier mods on the home brew sites for chillers. All depends on what you want to work with. If you are lucky enough to not be in a freezing environment, a DIY chiller can be a fun project.

I’m not in that situation, and when I get the chiller with a heater finished I’ll post pics… I hope it’s in it’s final phase before the freezing temps hit again.

Those bottles are the wrong colour - they should be green or brown :wink:

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