
P.12
it should be run OUTSIDE the pipe insulation but
UNDER the insulation jacket or wrap to protect the
wire from UV exposure.
4.7 Installing the Solar Tank
The solar tank is heated indirectly through a double
wall heat exchanger that is integral to the tank. This
kind of heat exchanger wraps around the tank shell
and under the insulation and tank jacket. Any leak
in the heat exchanger will be seen as fluid will leak
out from the bottom tray of the tank jacket.
When plumbing the SunEarth solar storage tank and
drainback reservoir make sure that all the compo-
nents are accessible and easy to reach. Ensure that
there is clear access to the storage tank, circulat-
ing pump, drainback reservoir, mixing valve, flow
meter and other key components. If a component
in the potable water side of the system may require
future service or maintenance make the connections
with brass unions. Use only brass nipples and unions
and copper and brass fittings in plumbing the solar
storage tank and drainback reservoir. The use of
galvanized fittings or nipples, CPVC or PVC piping
is prohibited.
Check valves are
NOT ALLOWED
anywhere in
the collector loop. A check valve in the collector
loop will prevent proper draining of the collectors
and may result in freeze damage. If the pump used
has an integral check valve, the check valve must be
removed before installing the pump in the system.
Hard copper connections to the city cold water
supply line and the home hot water feed lines are
recommended. The gaskets in standard water heater
flex hose connectors can become brittle and com-
pressed over time and begin leaking on the water
heater. If not detected in a timely manner even a
small drip or leak may cause serious damage to the
tank’s electrical components or, in extreme cases,
may cause the tank to leak from the outside in.
Tank plumbing is required to provide for the isola-
tion of the solar storage tank from the city cold water
supply line by means of an isolating ball valve.
The differential temperature controller shall have a
screen readout to show temperatures of the collec-
tor and storage tank. Otherwise, line thermometers
shall be installed in the collector supply and return
lines to allow for a simple diagnostic check of
proper system operation. On a sunny day the hot
water return line should be approximately 5 – 15°F
PROTECTIVE INSULATION
JACKET OR APPROVED
COATING
RETURN LINE
CRIMP OR SOLDER
CONNECTION
SENSOR WIRE
MUST
NOT
BE PLACE IN
DIRECT CONTACT WITH
PIPE
SILICON SENSOR LEAD MAY
BE IN CONTACT WITH PIPE
SENSOR CLAMPED TO HEADER PIPE
& COVERED WITH INSULATION
COLLECTOR SENSOR
fig. 8