Threads like this make me grateful that I have a basement that stays in the low-to-mid 60sF, even in the dog days in August. Nevertheless, the concept raises some interesting applications, not all of which require the investment in refrigeration equipment. It occurred to me that I'm literally sitting on a huge "cool sink" of ambient ground water, in the form of an old cistern just west of the house, probably 2000 gal. capacity, and which always stays around half full of water. I already have a small submersible pump, and plenty of hose, so that the cistern water could be circulated through an immersion chiller and back into the cistern, with no wasted water and virtually no temperature rise. Not only could this be used for chilling wort, but in the application described in the OP.