kpr121
Well-Known Member
I think you will need to experiment. The reason I say close to the output tube is consider this:
Say you have 5 gallons of chill water in the fermentor cooler and you want to maintain 60F. It takes some time for a thermostat to respond. If the pump moves 1 gallon of water (just one minute for a 60 GPH pump) before the thermostat shuts it down, you have a mix of one gallon of, say, 40F water and 4 gallons of 60F water - that averages out to 5 gallons of 56F. That might be a bit more swing than you want.
Again, it will take some experimentation, but I'd lean towards a short cycle to avoid over-shoot, and move from there as needed. With a compressor, you want to avoid short cycles, but I think this will actually be best with just a pump.
That's what I think also. Also, calculate how much water the IC holds. From my comments above, you may find that all you need to do is pump the contents of the IC over to the fermentor. After that, the water in the IC has some time to sit in the ice bath and give its heat up. You might not really need to transfer any heat as it is being pumped.
Please do report back. Let us know some things like the controller settings, volume of chill water in the fermentor, in the ice bath, the volume in the IC, and your pump capacity (it would be good to measure how long it takes to fill a gallon jug with it hooked up - to see how it handles the restriction of the IC and hoses). It really helps us to hear how the theories really work out in practice. I do think this will work well for you.
-kenc
Thanks for the comments. I have created a new thread here: https://www.homebrewtalk.com/f163/using-ic-mlt-fermentation-water-chiller-253770/
I will try to summarize my results here but for all details please refer to my thread above. This way people who do a search for this type of stuff in the future will find what they need.
From checking on the temps overnight, it hasnt overshot much (I currently have the probe on the opposite side of the pump). Held pretty steady around 62-63 F, until the ice melted sometime early this morning and the pump was running and only adding heat. I need to work on insulation so I can leave this alone for longer than once or twice a day.
Here's my ebay temp controller settings:
F1=17.0 C (set temp)
F2=0.5 (temp differential)
F3=1 (min. time in minutes that the controller stays 'off')
F4=0 (temperature calibration)