EcoRenovator - View Single Post - Shower pre-heat idea

hamsterpower · 03-11-14, 09:18 AM

I like that idea of preheating the cold line to the shower with the drain line. I had thought of trying to preheat the cold line feeding the water heater that way, but that seemed to be problematic. Preheating the cold line to the shower instead allows much simpler routing and only has effect when useful heat is literally going down the drain. I like it! Thanks.
Seems to me a thin, small diameter, flexible, copper cold line wrapped around a copper drain pipe is desirable. And where the warming cold line starts at the bottom and flow up the coil would have best heat transfer.

The one caution I imagine is if the hot line is too hot. So hot that there is not enough cold in the preheated cold line to temper it. But for that to happen there would be a bunch of other problems first.

I'm not so excited about using the heat in the shower floor to preheat the cold line as my feet are still enjoying that heat. It has not yet become waste heat.

03-11-14, 09:18 AM	#6
hamsterpower Apprentice EcoRenovator Join Date: Oct 2009 Posts: 142 Thanks: 0 Thanked 11 Times in 11 Posts	I like that idea of preheating the cold line to the shower with the drain line. I had thought of trying to preheat the cold line feeding the water heater that way, but that seemed to be problematic. Preheating the cold line to the shower instead allows much simpler routing and only has effect when useful heat is literally going down the drain. I like it! Thanks. Seems to me a thin, small diameter, flexible, copper cold line wrapped around a copper drain pipe is desirable. And where the warming cold line starts at the bottom and flow up the coil would have best heat transfer. The one caution I imagine is if the hot line is too hot. So hot that there is not enough cold in the preheated cold line to temper it. But for that to happen there would be a bunch of other problems first. I'm not so excited about using the heat in the shower floor to preheat the cold line as my feet are still enjoying that heat. It has not yet become waste heat.