3
The solar storage tank holds 120 gallons of potable water. It is
heated by a “wrap around type” heat exchanger made of
copper tubing. Heated solar fluid from the solar collectors
circulates through the “wrap around” heat exchanger and the
heat is passed to the water in the tank by conduction. The
“wrap around” heat exchanger design gives the highest
standard of protection for the potable water: Double-wall
venting prevents any contamination of water in the tank.
Back-up heating element -
An electric element is located
within the top 1/3 of the tank as a backup, and it is energized
whenever there is insufficient solar energy available. The
water heater maintains its own temperature independently
from the solar control. For example, if you set the tank
thermostat to 100
0
F., the electric element will be activated by
the water heater control to maintain the set-point. Its position
in the top third of the tank fosters thermal stratification such that
only the top third of the tank is heated electrically while the
water towards the bottom of the tank remains at a cooler temperature so that solar energy may contribute to
the domestic hot water need. The electric element should be set to the minimal acceptable water
temperature. Some users will shut the electric element off manually at the electrical box during favorable
solar conditions. In some cases, very high temperatures within the tank could trip the breaker in the tank and
need to be reset by pressing the red button.
Solar
Storage Tank
The solar storage tank with integral
“wrap around” heat exchanger
The solar collector
Electric
Element