SOL-Perpetua™ Solar Water Heating System Installation Instructions and Operating Manual For Series "A" Pumps
SOL Perpetua™ System Installation - Slope of Panels
The degree of slope of the roof and hence of the panels is not important for the action of the bubble pump. For best results, however, the slope of panels should be related to the latitude. In high latitudes the optimum year-round slope is approximately that of your latitude. If direct placement of the panels on your roof results in less than this optimal slope it is possible to prop them up but it may not be cost effective to do so. Appearance would also suffer.
The top edge of the panels should slope upwards toward the bubble pump at a minimum 2% slope in order that air will rise to the top.