Originally Posted by maily
I thought of a large stainless steel tank on the roof that ran into lots of tubes that ran accross the roof many time and then down into a very well insulated tank inside the roof. I dont know if this would be successful, but it would be virtually free hot water.
I have a friend in Sweden (of all cold places) who has a system like that.
He is getting 75-85 degree hot water from solar 8 month a year between March and October.
No need for a pressure pump if the tank is positioned high enough over the usage points.
The solar collector should be positioned lower than the tank so that the hot water
in the collector auto-circulates up to the tank.
The auto-circulation will stop when tank water has the same or higher temp than
the collectors water.
Most important is the insulation of the tank, you don't want to get heat losses there.