d) Following these steps to install the sensor:
STEP 1: Wet the sensor tip and cable with water.
STEP 2: Slide on the rubber sensor plug, provided in the manifold box.
STEP 3: Coat the sensor probe with heat transfer paste.
STEP 4: Insert the sensor into the sensor port and push rubber plug into place
STEP 5: Use cable ties to secure the cable in place against the insulation pipe.
5.3. Pipe Insulation
a) Heavily insulate all piping running to and from the manifold with a high quality insulation of at least 15mm/0.6”
thickness, preferably thicker in cold climates.
b) Insulation foam that is exposed to direct sunlight should be protected against UV related degradation by
wrapping/covering with a suitable material such as adhesive backed aluminum foil, PVC conduit or similar.
c) Ensure that the insulation tightly covers the inlet/outlet ports and is sealed against the manifold casing with
silicone sealant or foil tape to prevent water ingress.
d) For systems designed to allow stagnation, high temperature rated insulation such as glass wool or mineral wool
should be used on piping close to the collector (~2m / 6’). Glass wool insulation may come with an external foil
wrap, but any cuts made during installation should be sealed with watertight and UV stabilized material such as
adhesive backed aluminium foil.
5.4. Air Purge
a) Once the inlet and outlet are connected to the plumbing system, the collector loop should be purged of air.
b) Mains Pressure Direct Flow (Open Loop):
• Without Air Vent: Install a drain valve on the return line (collector > tank) ball valve between the drain valve and
the tank. With the ball valve closed open the drain valve allowing air to escape as the mains pressure water
forces through the solar collector line. If the collector is hot steam and hot water may be expelled to extreme
care should be taken! Once the drain valve is no longer releasing air it can be closed and the ball valve opened
so that normal operation can begin.
• With Air Vent: With the air vent installed on the return line (collector > tank), isolate the return line after the air
vent with a ball valve allowing the mains pressure water to purge the collector of air. Always remove or isolate
the air vent after the air purge.
c) Low Pressure Direct Flow (Open Loop):
• Run the pump at the highest speed settings, forcing air out of the manifold and back into the tank.
• If an auto-air vent is installed on the outlet of the collector, air will be automatically eliminated from the solar line.
If using a manual air vent this should be opened until all air is eliminated.
• Always remove or isolate the air vent after the air purge.
d) Closed Loop:
• The solar loop should be filled with glycol/water mix (or suitable heat transfer fluid), vented and pressurized.
The exact process will depend on the design of the loop and components used. Refer to relevant instructions
specific to the pump station and filling equipment used.
e) One the system is purged of air a check for leaks at all connection points should be completed. For closed loop
systems the system should be pressure tested prior to air-purge process.
5.5. Pump Selection
a) Pump should be selected to meet the following requirements:
• Flow-rate: The nominal summer flow-rate per AP-30 collectors is (0.1L/tube / 0.026G/tube each minute) to
achieve ~7
o
C temperature rise during normal operating conditions.
• Head pressure: Select a pump that has sufficient heat pressure to overcome the pressure drop of the solar
collector, flow and return lines at the desired flow-rate. For drain-back systems the vertical distance from the
drain-back tank to the collector must also be considered.
• Material: For closed loop systems a cast-iron body pump can be used. For direct flow systems a brass/bronze
or stainless steel body pump is recommended.
b) Where possible use a controller with variable speed pump control so that flow rate can be adjusted to achieve the
desired temperature rise. The table below provides the temperature rise at different flow rates based on collector
midday peak output when (when tm - ta delta-t = 0 and G=1000W/m
2
). Values of up to ~15-20% higher are
possible in the 2 hours either side of midday due to the IAM factor.
Apricus Solar Collector Installation and Operation Manual - International Edition
Copyright ©
2013 – Apricus Solar Co., Ltd A11-01.1.1-PB-V16 Page 17 of 27
