The Science
Plumbing diagram for evacuating tube
The controller uses the temperature sensors, t1,
t2 and t3 to turn the pump on and off. When t1 is hotter than t2 the controller
switches the pump on. The hot water on the roof is then pumped down through
the bottom coil on the tank, heating all the water in the tank. When t1
approaches the temperature of t3, the controller switches the pump off,
completing one cycle. The more sun, the more cycles.
