I bought an immersion chiller and used it for the first time this week. It works great. I do 2.5 gallon batches and it cools the 2.5 gallons very quickly but only down to about 80 degrees. I live in central Texas and our cold water is 77 degrees. I did the chilling outside on the patio so I could hook up to the garden hose and even with the somewhat "cooler" fall temps the water is still not "cold". In the future I'm going to have to do an ice bath afterwards to get it down to 70. I was hoping to avoid the ice as it's a pain, but I pitched the yeast this time around at 76 as that's our indoor room temp. Put it in my temp controlled fridge and it got down to 68 by the next day and fermentation finally started. I guess this a southern state problem due to the heat. I had assumed my cold water would've been a little colder, though.