So, I acquired a 15 gallon corny keg that I intend to use as a fermenter and I have a few items that I'd like to use to cool it for ale ferments.
I have a diaphragm pump and a keezer in close proximity. I also have a Love controller.
Here's a couple of thoughts.
I have 47' of a thin walled SS tubing coil (was 50') that I intended to make a HERMS coil out of but I couldn't bend it enough for that so I bought a SS immersion chiller to replace it. I was thinking I could put the corny in a tall trash can in water with the coil and place a pot of water (or a mix of glycol) in the keezer and recirculate cold water through the SS coil to cool the corny. I would use the Love controller with the probe inside a thermowell in the keg to tell the pump when to turn on.
The other idea for the cooling coil is something like the brewhemoth immersion cooler coil as can be seen here. It would go inside the keg. I have a corny keg lid with a stopper in the middle and thought I might be able to get a chiller like that through the lid.
Edit: I know I could just buy a fridge but that's not as much fun! I think I'm going to try it out with the stuff I already have and if it doesn't work well I'll just buy a fridge. I think the internal chiller is cool but I'd have to buy one since I lack the skills to make such a small coil and it'd be a bit much to do that. I'll update with pics if it works out.