So I have 50' of 1/2" SS tube... Chiller ideas

I picked up 50' of 1/2" stainless tube on Ebay for cheap. I am now deciding how best to incorporate into my stand build. Here is my thought so far....

I am thinking of making a counterflow heat exchanger that could be used as a HERM heat exchanger and as my wort chiller. I have two pumps, so my thought is to pump HLT water that is maintained by an electric element at my setpoint through the outer shell, and pump mash wort through the inner coil to maintain my fixed mash temp. I have direct fire for temperature steps.

Then for chilling, I would recirculate the BK throught he CFC and whirlpool. I would use hose water to knock the temp down to 120 dF, then pump ice water through to finish my temps.

Hopefully, this would give my a fast full volume pulldown.

My main question is, how much length should I use. I feel like 50' might be overkill. Maybe 30, 40,.... suggestions would be great.

Thanks

Build two 25' CFCs. Sell one to recoup your entire cost. Then you've got your CFC for free.

I was thinking of that, but do you think 25' is enough?

25' is overkill I've read. I generally need to turn my water down to a fairly low flow rate to keep my wort from getting too cold (especially in winter).

SS vs copper as for heat conductivity, well it's really thin walled stuff and I don't think there is enough difference to worry about, most likely the SS will be thinner wall than copper even.

My situation is a little different because I plan to recirculate the hot wort in the BK. So I will be getting the wort running through the chiller as cold as possible, then returning it to the kettle to help cool the rest of the wort.

What about this... two 20' parallel counter-flow chillers. Output of the kettle feeds my pump, after the pump the wort is split into two flows, each running through a 20' chiller, then the flow re-unites and runs into the kettle. That should provides me some wicked fast chilling, and make use of the chilling potential of all the stainless.

I could sell some of it, but I figured I already have the clearance for this purchase, and if I sell it that money would go to something silly... like food

Seems like splitting the flow into 2 CFCs would be overkill and pointless. If you really wanted to use all of your tubing just make a 25' CFC and then save the other 25' for a HERMS coil