kal
Well-Known Member
You don't have to make up for it really.Copper is a better conductor of heat. True. But you can make up for the difference with A- more tubing and/or B- higher temp water. Seems like these could be practical trade offs to me.
I see often people quote that copper is a better conductor of heat than stainless. That is true, but with a HERMS coil where the two liquids exchanging heat are almost at the same time (usually within a degree or so from each other) this difference in heat transfer efficiency is no longer relevant.
Where it matters and the difference is noted is when the two liquids are much farther apart in temperature such as a CFC (counterflow chiller) for chilling wort from boiling down to pitch temps. There you could easily have a 140-150 degree F difference.
So get a stainless HERMS coil, but a copper CFC.
Kal