Rob wrote:

> True, but stainless would work, and there are folks who sell steel
> Hypodermic Needle tubing with very thin walls.
>
> Personally, not a big problem for me, but I live where it usually isn't
> too hot outside during fermentation season, and my batches aren't big
> enough to need such cooling.
>
> Very cool idea, though.
>
> Rob

Thanks, Rob, for the encouraging words. Also a thank you to Mike and
Droppy for pointing out the problem with copper, and to the other
posters for their comments, too. I'll just cover everything in this one
post.

So long as the reduced thermal conductivity doesn't present a problem,
stainless would be fine in place of copper.

When Scott pointed out that, without a pump, the amount of pipe within
the fermenter may not be adequate for the amount of heat to be moved, he
may well have hit the nail on the head, but I'd like to see if I can
locate some precise figures or a formula or something like that. That
was one of the main questions that I'm researching -- how efficient is a
heat pipe, and how can I build or acquire one if one should work? The
question has never, in my mind, been about the peltier.

Cheers, Bill Velek
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