While I've read through the vast majority of this thread with great interest, as I'm getting ready to implement this passive tower cooling solution, forgive me if this has already been brought up, but just came to mind.
While the copper tube conductive conduit wrapping the beer lines into the tower does seem to make a significant improvement, the point was brought up that the taps would still be warm, if only for the first pour. I haven't even implemented this yet, but this seems plausible. So here's what comes to mind.
Why not run the beer up to the tap in metal lines, rather than vinyl? You would obviously have to have some sort of adapter to switch back to vinyl tubing after a short run inside the refridgerator. I don't think you would need copper. You could probably use the same type of line that attaches to the tap. The thing is I don't know if there are readily available connectors or if I would have to thread the ends myself.
This seems like it would also accomplish cooling the tower passively, but all the way up to the tap. Of course, you would be inefficient at the tap, as it itself is not insulated. But maybe instant cold pours at any time. Any thoughts?
Thanks for the post!