SOL-Perpetua™ Solar Water Heating System Installation Instructions and Operating Manual For Series "A" Pumps
SOL Perpetua™ System Installation - Panel Orientation
Should the roof not permit the ideal orientation, i.e. sloping the panels to the south in the Northern hemisphere and sloping to the north in the Southern hemisphere, consider having one panel sloping to the South East and one to the South West in the Northern hemisphere or one panel sloping to the North East and one to the North West in the Southern hemisphere. A system with such arrangement will produce hot water for as much as 10 hours per day in the summer. This arrangement works without any loss of heat from the panel in the shade if two back flow preventers, also called check valves, are installed, one on each pipe leading from the bubble pump to the bottom of each panel. Otherwise warm fluid will flow backwards through the panel in the shade thus losing a considerable amount of heat. These valves are very simple, inexpensive and trouble free.
A system as described above was observed one winter morning producing hot water with one panel in the sun while the other panel in the shade was covered in heavy frost.