If you have purchased a large solar hot water system because you intend to use it for Radiant
Space Heating, or simply to provide a higher solar fraction in your hot water heating, you may find that you have excessive heat in the summertime-which can make your home uncomfortable. There are two simple solutions to this problem; a heat dump, and seasonal compensation installation angles.
A Heat Dump siphons excess heat off of your Solar Hot Water System and dispenses it to exterior source. A Heat Dump can be as simple as using the excess heat for your pool or spa, or you can purchase and install a specialized heat dump which is basically a set of radiators that allows you to dispose of this heat externally to keep your home comfortable.
The Second option is what is known as Season Compensation in your Installation Angle. The nice part about this, in the summer it will lower efficiency to keep your system cooler and your home more comfortable,
but in the winter time, the exaggerated angle will increase efficiency providing extra heating capacity from the same number of solar collectors.
• Try mounting your collectors 20-30 degrees higher than recommended by your latitude (i.e., 40-50 degrees instead of 20 degrees)
• In the winter you will get additional performance because the higher angle will put your collectors closer to flush with the sun at its lower winter angles, decreasing the amount of sun that is kicked off by the angle and not absorbed
• In the Summer you will get lower efficiency, and no overheating because the higher angle will in crease the kick off of sunlight, and lower the absorption rate
The Image at the top of this page shows this theory in place by comparing the sun's angles and elevations at opposite points of the year.