Green Collar Careers - System
Section 401 you were introduced to the primary components of a
solar water heating system, now we'll put them together on a
Click on the image at the
right to open the system diagram to see the recommended system
configuration. This configuration has been in use for many
years and has proven the most cost effective way to construct a
cost effective durable solar hot water heating system.
This system diagram uses a dual purpose storage
Closed Loop systems require an Air Vent
to bleed out air from the highest point in the antifreeze circuit.
The circuit is equipped with its own Pressure
Relief Valve and should be located outside near the solar
The Floating Ball Check Valve prevents
flow of water when the pump is shut off to avoid cooling the
storage tank from convective flow of water.
Antifreeze flows through the heat exchanger that is wrapped around the
storage tank. Antifreeze exiting the heat exchanger is the
"cold" side which is usually about 10° warmer then the storage tank.
Both hot and cold sides of the Closed Loop plumbing need to be
There are service ports on the cold side, one to drain
the antifreeze, one to fill it. Valve V1 is used to fill
the system, Valve V2 is used to drain the system, and Valve
V3 shuts off the path between V1 and V2 to force the filling fluid
through the entire system rather then straight back out between V1 and
There are two Temperature Gauges (optional) one on the cold
side, one on the hot side which are recommended to give a visual
observation and back up to the thermocouples. Should there be a
failure these gauges are handy to use for diagnosis.
Also on the cold side is an Expansion Tank with an optional
Pressure Gauge on top. The gauge will measure low
pressures and is handy for diagnostics such as pump failure.
Finally the Pump is shown with a Polar PV panel to provide
power. What is not shown is the controller and thermocouples.