I made two of these when building one for myself since it is so much cheaper to purchase the 3/8" copper tubing in 50' sections. I use one and I am selling the other. I have used the other one to cool off several batches and this design is very effective. My system is gravity fed, so it takes a little while to cool off the whole batch. I'm planning on getting a pump to speed the process.
It was made using BobbyM's design. It uses approximately 23 feet of copper tubing surrounded by a yellow hose. I tested it out with boiling water and it cooled off the water to the ambient temp of our cooling water with no leaks. Other than testing this out, it is brand new.
I am selling this for $50 shipped anywhere in the lower 48 states.