P.10
affect the system performance. A thorough clean-
ing is required before charging. A Water soluble
flux should be used when soldering pipe joints in
the collector loop in order to facilitate system flush-
ing. Carefully review the cleaning procedures in
“Charging the System” outlined below.
All vertical piping between the storage tank and
the collector shall be supported at each story or at
maximum intervals of ten feet (10’). Horizontal
runs shall be sloped to drain (minimum 2% slope)
and supported every five feet (5’) to prevent sag-
ging. Roof runs shall be secured and supported
providing at least 1-1/2 inches clearance from roof.
Pipe supports shall be constructed from a material
that will not rot, compress or degrade over time
as this may lead to pipe sagging and failure to
drain. Standard best piping practices shall be fol-
lowed as described in the Uniform Plumbing Code,
International Plumbing Code or other recognized
code or standard. Plumbers tape or tube strap is
required. The pipe insulation should not be com-
pressed or crimped by the strapping material.
Allowance should be made for expansion and con-
traction of piping due to changes in temperature of
the water and piping. Use flexible pipe supports and
avoid long straight piping runs. Include bends and
elbows to allow for expansion such as swing joints
at the collector inlet & outlet.
The installation of all horizontal and vertical piping
may not reduce the performance or rating of any
structural member or fire rated assembly. Adhere to
all applicable local codes and ordinances.
4.5 Pipe Insulation
WARNING: HOT PIPES MAY CAUSE
BURNS IF TOUCHED. ENSURE THAT
ALL PIPES AND FITTINGS ACCESSIBLE
TO THE PUBLIC ARE WELL INSULATED.
COMPONENTS ACCESSIBLE TO PUBLIC
TRAFFIC MUST BE KEPT BELOW 140ºF
OR CLEARLY LABELLED WITH AN
APPROPRIATE WARNING.
The collector loop piping, plus any interconnecting
hot water piping shall be well insulated with a high
quality flexible closed cell insulation to minimize
heat loss. In addition, the final 5 feet of metallic
cold water supply pipe leading to the system, or
the length of piping which is accessible if less than
5 feet, shall also be insulated. The insulation shall
have a maximum operating temperature of 220°F or
higher and a minimum thermal resistance of R-2.6.
The wall thickness of the pipe insulation should be
½” or thicker. A 1” wall thickness is required for
exposed piping in all areas prone to annual hard
freeze conditions. When it comes to pipe insulation
the rule is simple: thicker is better.
To the extent possible, slide the insulation material
over the pipe without cutting or taping. All butt
joints must be sealed with contact adhesive. The use
of rigid polyethylene pipe insulation is prohibited.
The temperatures generated by your collector in the
summer months or under stagnation conditions can
melt this type of material.
Any above ground exterior pipe insulation shall be
protected from UV degradation and moisture dam-
age. Insulation must be jacketed, wrapped with alu-
minum foil tape, or painted with two coats of high
quality water-based acrylic resin coating as supplied
by the insulation manufacturer.
4.6 Control System
4.6.1 Differential Controller
The differential controller must be installed in an
accessible location so that the user interface, typi-
cally and LCD screen, can be seen. Switches on the
controller must be labeled and accessible. Always
follow the controller manufacturers wiring diagram
when installing differential controllers. Control sys-
tem inputs; such as signals from temperature sensors
or flow meters will be connected to the appropriate
low voltage terminals. Controller output to the
pump will be medium voltage, 110 VAC or 220
VAC. Medium voltage power to the pump may be
supplied by a line cord from the pump to an outlet
in the controller or hard wired from the controller
medium voltage terminals to the pump. Wiring
must comply with standard electrical practice and
all applicable electrical codes for the jurisdiction,
this may require the use of conduit for medium volt-
age wiring.
The differential controller must have a provision to
manually turn the pump on and off (manual over-
ride) so that pump operation can be checked at
any time and the pump can be manually stopped if
required for maintenance or troubleshooting pur-
poses.