EcoRenovator - View Single Post - Solar "Batch" Water Heater, help please....

Ryland · 10-30-11, 10:01 AM

I've used batch type heaters that were just a 50 gallon drum in an insulated box with a single pane of glass over it and it was connected right to a shower, no tempering valve or anything, it would get warm, 90 to 100F, nice for showering under, but because it had such a small collection area the heat input was small.
If you had more surface area you would get more heat, one batch heater I saw was two pieces of 4" copper pipe 8' long in a covered and insulated box, that made for a steamy bath but the cost of copper was higher.
Water heaters already come with a tempature pressure valve, use that common off the shelf part and it will thread right in to standard pipe thread.
Trouble with batch heaters is that they radiate heat almost as fast as they absorb it, unless you have a good way to concentrate the light with reflectors or something, it will cool off pretty quickly over night, that is why flat panel collectors are popular, they get hot and store that heat in a protected insulated tank.

10-30-11, 10:01 AM	#2
Ryland Master EcoRenovator Join Date: Mar 2009 Location: Western Wisconsin. Posts: 913 Thanks: 127 Thanked 82 Times in 71 Posts	I've used batch type heaters that were just a 50 gallon drum in an insulated box with a single pane of glass over it and it was connected right to a shower, no tempering valve or anything, it would get warm, 90 to 100F, nice for showering under, but because it had such a small collection area the heat input was small. If you had more surface area you would get more heat, one batch heater I saw was two pieces of 4" copper pipe 8' long in a covered and insulated box, that made for a steamy bath but the cost of copper was higher. Water heaters already come with a tempature pressure valve, use that common off the shelf part and it will thread right in to standard pipe thread. Trouble with batch heaters is that they radiate heat almost as fast as they absorb it, unless you have a good way to concentrate the light with reflectors or something, it will cool off pretty quickly over night, that is why flat panel collectors are popular, they get hot and store that heat in a protected insulated tank.