One of the key advances over the past 20 years has been the development of affordable and cost effective evacuated tube collectors. If you live in an area that one would not consider very sunny, it is important how your collectors will function on partially cloudy and cloudy days. This question becomes even more important in those areas during winter when it is cold. Flat plate collectors loose too much heat to be operable in cloudy or partially cloudy weather in very cold climates.
Every tube on an evacuated tube collector is like a thermos bottle. It holds on to the heat it collects from the sun, even when the heat is small, thus allowing your hot water to be heated for your home.
Sunrise through two FC4715-30D's setup to track the sun from East to West. This array seeks the brighest spot in the sky and adjusts itself once every 5 minutes for a
period up to 5 seconds. Tracker has reverse lock out. Tracker board made by www.redrok.com. Model LED3X with
reverse lockout and night time reset.
These are two FC4715-30D's mounted on a roof with Elephant racking to steepen the total angle a bit. In this example, all piping and insulation is complete just prior to tube insertion which is the last aspect of assembly. The system is fully functional once the tubes are inserted and usually starts to "cycle" when the tubes are being inserted. This system happens to be a DPDB with an 80 gallon storage tank.
The Chinese Mfg. SunFlower Solar has a new website and expanded product line. There website is at www.sunflower-solar.com for your reference.