Upgrade to cooling water using portable aircon

[Johnny Smith]

Hi all, last year I upgraded my Chinese Red Black 60W laser to 100W, but I was still using the OEM supplied fish tank pump and a large drum of distilled water. I had hoped that overnight my water would be able to cool down sufficiently to allow me to run the laser all day in the cooler months and at least in the mornings during the warmer months. The Australian summer had other ideas. So what to do? I could buy a chiller but they are pretty expensive for what you get, at least here in Australia and they only serve one purpose.

After some research I decided to purchase a portable air conditioner as it would help cool not only the water but also the garage. To do this I purchased a copper radiator normally used for liquid CPU cooling in computers......can't use aluminium radiators because corrosion inhibitors can't be added to the laser cooling water. I made a frame to mount the radiator at the air cons cool air outlet so the cold air would blow through it. For cooling water circulation I'm still using the OEM pump to push the water through the radiator before going to the laser tube with the return going straight back to the tank. I have a dual temp gauge monitoring water temps at the laser tube inlet and outlet.

Performance has been great with tube outlet temps maxing out around 23°C even when the outside temps are 35°C. On cooler days the water temp is below 20°C. In case you're inclined to tell me those temps are too high, the RECI instructions provided with my 100W tube state a max water temp of 40°C....which of course I have no intention of going near.

My portable air con is rated for 3.5kW cooling.

[Johnny Smith]

Here are some photos of the portable aircon, hot air exhaust and cooling water tank. The air conditioner blows air out the top through adjustable vanes. The radiator is mounted via a bracket that just sits on top of the aircon so it can be taken off in seconds. The hot air exhaust is connected to a pipe that goes up the to roof.....and before someone comments, yes I know the copper is way overkill. It was just what I had lying around from a completely different project...long story. The water tank is 100 litre but I only have around 50 litres in it. On cooler days, I dont even need the aircon running unless I'm cutting for extended periods as the heat capacity of the water is quite large. I can if needed also run the aircon in fan only mode...again, on cooler days that's all that is needed.

Anyway, that's it for now. Hope this helps someone.