Does anyone have experience with an immersion chiller for fermentation. I ferment in a 25 gallon conical and would like to be able to control fermentation temperature. I thought about building a cabinet of some sort but I barely have enough time to brew and am reluctant to take on a project that large. I also thought about an upright freezer with a controller but it is hard to find one larger enough for my fermenter. Then it occurred to me that an immersion chiller might be an option. I've seen a couple of references to such a device but have lots of questions.
Should I use stainless or copper tubing?
What length of tubing do I need and what diameter?
Would a flat spiral design be better or should I go with a traditional cylindrical coil? Must be able to clean and sanitize.
Would an ice bath in a cooler be sufficient or should I place the "hot" coil in a chest freezer or refrigerator?
If anyone could offer any advice, I would really appreciate it.