[jmsetzler]

Does the AHBS version have the wire tacked on the outside of the inner tube for turbulence?

I don't think so.  I looked at some of those and that was also what I was trying to build.  The price doubles on a pre-made one with that option.

[Stevie]

Does the AHBS version have the wire tacked on the outside of the inner tube for turbulence?

I don't think so.  I looked at some of those and that was also what I was trying to build.  The price doubles on a pre-made one with that option.

Good to know. Bummer it adds so much. I seems like the second easiest part of the build.

[jmsetzler]

Wrapping the copper wire around the tubing and soldering it in place wasn't so difficult.  It was time consuming though.  It WAS difficult to slide that through the hose though.  I had a difficult time getting it through 5/8" ID braided pvc hose. 

I'm not a physics or engineering major, but I'm not so sure that the copper wire wrap for 'turbulence' provides a SIGNIFICANT increase in performance of this type of chiller.  I think the best performance boost a counterflow chiller can get is by having cold water to pump through it.  I have a 50' immersion chiller that I built a long time ago and during the warmer summer months when my ground water out of the spigot is 85°, I plan to use the immersion chiller in a cooler full of ice water as a pre-chiller for the water I'm pumping through the counterflow chiller. 

[Stevie]

Also, let us know how you think it will hold up if recirculating for a while before turning on the water. I'd want to recirc for 5-10 minutes before flame out.

[S. cerevisiae]

Austin Homebrew Supply sells this model that I ordered yesterday:

http://www.austinhomebrew.com/Beer/Chillers/Counterflow-Wort-Chiller-25-Foot.html#.VEbac_nF98E

I built two counterflow chillers of that design using Watts EPDM rubber heater hose that is good to 212F.  One chiller is wound clockwise.  The other is wound counterclockwise.  They are designed to be stacked with tap water running through the top chiller and chilled water running through the bottom chiller.   The only difficult part in making a chiller of this design is drilling out the stops in the NPT to tube fittings.  A drill press and a drill press vise makes the job much easier.  I never use either of the chillers because an immersion chiller is so much easier to use, my tap water never gets above 65F, and I do not brew as much during the summer as I do during the winter.