State Standard Systems - Manual (Page 20)

20
collector pipinG detail
The outlets of the collector are 1” copper pipe nipples. See
Figure 19. They should be piped as shown with provisions
for an air vent. The air vent must be oriented vertically as
this must be the highest point in the system in order for air
to escape. This will prevent air lock and subsequent loss of
system efficiency. Teflon® tape or high temperature, high
quality pipe sealant should be used when making threaded
connections.
The collector inlets should be piped similarly but without
the air vent.
sensor WirinG at collector
The wiring used to connect the sensors to the controller
should be a minimum 18 AWG. The wiring should be two-
conductor, PVC UV resistant suitable for outdoor use. Use
Belden Wire No. 7409A or equivalent.
sensor mountinG at collector
The angled collector heat sensor is mounted to the outlet of
the collector. See Figure 20. The stainless steel screw clamp
should be used. The entire sensor should be wrapped
thoroughly with insulating stretch tape such as MOCAP
Silicone X-Treme Tape® so that the sensor is isolated from
the outside air. If possible route the sensor wire through the
roof with the collector piping and connect the sensor wire
to the sensor extension wire with wire nuts.
Figure 20.
pipinG throuGh the roof
Preserving the integrity of the roof membrane is the
most important roofing consideration. Ensure that all roof
penetrations required to plumb and mount the solar collector
are properly flashed and sealed in accordance with standard
roofing practices.
The return and supply lines should be supported under the
roof to prevent undue stress on the piping assemblies at
the collector. Hangers shall provide adequate support and
correct pitch of pipes. Hangers or supports for insulated
pipes or components shall avoid compressing or damaging
the insulation material. Piping should be sloped toward drain
ports with a drainage slope of no less than 2 cm vertical
drop for each meter of horizontal length (1/4 inch per foot).
pipe insulation
The collector loop piping (exterior and interior) must be
well insulated with a high quality flexible EPDM closed
cell insulation to minimize heat loss. The wall thickness
of the pipe insulation should not be less than ¾”. A 1” wall
thickness is required in all areas prone to annual hard
freeze conditions. When it comes to pipe insulation the
rule is simple: thicker is better. The specified insulation
material is Armacell UT Solaflex or equivalent. As part of
the insulation requirements the final 5 ft of the cold water
inlet to the storage tank must be insulated.
To the extent possible, slide the insulation material over
the pipe without cutting or taping. All butt joints must be
sealed with high temperature contact adhesive. The use
of rigid polyethylene pipe insulation is prohibited. All
outdoor insulation should be protected from moisture and
Ultraviolet deterioration by either paint or foil tape.