... existing energy source 4.CE Solar U Pipe Collector,2011 new solar U pipe collector,U Pipe Collector,2011 solar water heater,heat ... ,new solar pipe collector,copper solar collector,U pipe collector The U Pipe series solar collector are always connected with existing heating supply device ... liquid(usually a glycol-water antifreeze mixture) in the U pipe heats up, and conducts the heat energy to the water ...