@Ariel_Yahni_UniKpty I’m not sure but the water in the return tube is still cold after several hours. I’ve been wanting to get a thermometer and flow meter though.
@Ariel_Yahni_UniKpty You have a shot there, I think you need about 1200btuh if my memory serves, and that’s about 1/5th the size of the smallest room AC, to give you a rough idea what size it might be. I’d think if they’re investing in going with a freon type loop, they would be making it recover quickly enough for high volume use (like an office building with 10+ users)
I just tested the water temp coming out of this and was almost 61F
This might help you work out the numbers,
A BTU is the amount of cooling/heating required to lower or raise 1 pound of water, 1°F at one atmosphere.
Assuming that you are near 1 atmosphere (you aren’t on top of a mountain or something), 400 gallons of water is about 3,335 pounds so to cool this from 70°F to 45°F (25°F change) requires 3,335 pounds x 25°F change = 83,375 BTU. To change 400 gallons of water just 1°F requires 3,335 BTU.
You might need or want to apply a time factor to your analysis. Perhaps you want to cool 400 gallons of water from 70°F to 45°F in 2 hours. The cooling system would then need to remove only half of the 83,375 BTU’s each hour so your cooling system could produce one half of the cooling it would need to cool the water in 1 hour.
Here is a handy formula for calculating the cooling requirement of water:
BTU = Gallons x Temperature Change (°F) x 8.33
Thanks to:http://www.advantageengineering.com/index.php
These guys make Industrial Chillers and know the business well.
Interesting, should we be thinking about using an external pump vs a submersible one. My stock K40 water pump is 30W, isn’t that 30W that I have to cool in addition to the wattage of the laser tube?
An additional site if you are thinking about peltier technology. Peltier - Cooler Module Calculator - TE Technology
By my simple calcs, a peltier would need a capacity of about 139 watts for a heat load of 70 watts creating about 10 degrees change. The peltier coolers above from Amazon are 60-70 watts … marginal. It looks like a home brew dual peltier would work.
Something like:
A heat exchanger (CPU heat sinks) & mounting in bucket $40
A 24V 12 amp supply $22
2x modules @ $44
A simple solution is to pickup a good size dorm refrigerator drill holes in the door for you coolant tubes and place a five gallon bucket inside. note, you may be tempted to drill into the side of the refrigerator but there is a chance you may hit tubing or electronics the door is a safe bet. This is a very cost effective way to get a reliable cooling system. Because the water is already cold before you start you job the refrigerator only works a little to dissipate the heat generated during the job. If you keep your eyes open you can pick these up for $20:-)