My chiller is a CF similar to a “Chillzilla” that I have had for at least 13 years. The ground water right now is about 66-68°F. If I run the wort very slowly I’m lucky to get it under 75. Seems like it is getting warmer even though I am good about rinsing, cleaning, soaking… you get the picture.
The next step will be to use the immersion chiller that came with my 3B sculpture to pre-chill then go with the CF. A minor PIA but whatever works. I already tried running the ground water through the immersion in a tub of ice water to bring down the water temp some first. It works marginally well.
So what is the difference everyone gets between the ground water temp and the wort temp with your CF chiller or addition steps to help?
BTW I use gravity to run the wort through and open/close the ball valve on the kettle to adjust the flow.