I know this is a little off topic, but I am looking to cool a 3o" square insulated box to run from 60 to around 38 degerees. I would like to get good control and drop it a couple of degrees a day till I get to 38 in a couple of weeks. this makes the yeast work in a different way than regular fermentation at around 7o degerees. I have access to some coils and old equipment, including old water fountians, I wonder if a water chilled box would be the best?? thanks for any input.