I boil up five gallon batches split between two pots due to issues with my stove and my poor aching back -- it's much easier for me to manage 2x 2.5 gallon batches than one 5 gallon batch. I have 50 feet x 3/8 copper coming in the mail soon, and I'd appreciate input on the most efficient way to cool the two pots with immersion coolers.
As background, my water right now is about 70 degrees and the sink's water pressure isn't that high -- it takes about 50 seconds to fill a gallon.
Does it make more sense to
A) Make one 50 foot chiller and cool one pot at a time?
B) Make 2 x 25 foot chillers, put one in each pot, and run just one line from the faucet into pot 1, then connect the outflow to the chiller in pot 2?
C) Make 2 x 25 foot chillers, put one in each pot, and connect a splitter to the faucet so that 2 streams are running simultaneously?
Under scenario A, you have the disadvantage of one pot sitting at high temp and doing things like changing the hop profiles a bit between the two batches. On the other hand, I'm not a purist about these things and I don't think I'd notice it significantly once the two are mixed in the fermenter. It's also a bit more work and watching, but it's less hardware and connections.
Under scenario B, the water running through the second chiller is going to be fairly warm. On the other hand, if it were a single 50 foot chiller in a single 5 gallon batch that would be the case for the second half of the run, and yet people still get a benefit from using 50 foot chillers in their 5 gallon batch, so there must be a benefit to running 2 x 25 foot chillers in 2 separate pots. And as the first pot cools down, this becomes less of an issue for the second pot.
Under scenario C, you get the benefit of dedicated cool streams of water, but the flow will be a lot slower, so you get less cooling. It's certainly possible, though, that the flow will still be fast enough that this won't be an issue.
I suppose I could also get a big pot and mix the two batches after the boil is done, and use a single 50 foot cooler, but that seems to run the risk of hot wort aeration, it's more cleaning, and one big mass of wort would presumably take longer to cool than two smaller batches.
Does anyone have any input on the best way to go?