Installation manual

GENERAL DESCRIPTION AND INTRODUCTION SECTION 1
5
BASIC OPERATION: (SEE FIG 1)
Solar irradiation energy incident on the the solar collectors is transfered (in the form of heat
energy) to the solar circuit fluid. The circuit fluid is pumped around the system, transferring
t
his heat energy to the storage cylinder, indirectly via a coil.
I
n GlazedGlazed Flat Plate CollectorsFlat Plate Collectors heat is transferred to copper pipes carrying the heat transfer
fluid with the assistance of an absorber plate. This is located within an insulated frame with a
glass cover. This allows solar radiation to pass through but limits the heat lost through
convection and conduction.
The fluid is transferred around the circuit by a pump. This is switched on, when the
temperature or the surface of the collector absorber (for glazed flat plate collectors) or the fluid
exit temperature (for evacuated tube collectors) is greater (by a fixed differential) than the solar
portion of the DHW cylinder. The energy from the collectors will be transferred to the water in
the storage cylinder.
As the solar circuit is a closed system expansion vessels and relief valves are required.
COLLECTORS
The collectors are generally arranged in FIELDS (an array of collectors). Each field located
differently to maximise the irradiation collection throughout the day as the sun èmovesê
through the sky. Normally only one field is used placed in the optimum position. Multiple fields
are used when a more even heat gain is required throughout the day, space is limited or
where not one available location is ideal.
FIELDS
The solar irradiation can not always supply the DHW required at times of demand. Also
dependant on time of the day or month of the year there could be no solar contribution. A
‘top up’ system ensures that there will always be DHW available at the correct temperature.
The ‘top up’ system must always be sized on the basis of no solar contribution being
available to ensure the DHW demand can be satisfied.
We have two types of systems for utilising ‘top up’, combined and pre-heat:
In a combined systemcombined system (twin coil/immersion heater) the same cylinder is used to reach the
desired water temperature via two coils. A lower coil is used to transfer the solar heat to the
lower section of the cylinder, a higher coil heats the upper section using high grade heat from,
for example, a heating system or an electric immersion heater.
In the SOLARflo systems a full primary heating system can be included, utilising dedicated or
non-dedicated boilers. If a primary system is already available this can be diverted via a
pump, or valve or an immersion heater installed. The SOLARflo system can offer
control/communication of this primary section in order to maintain the water temperature
within the cylinder.
‘TOP UP’
COMBINED
SYSTEM