gledhill Torrent Stainless OV, Instruction Manual

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Page 16 Page 17
S Plan Open Vented Heating System Including Solar Input
Auxiliary
central
heating
Solar
controller
Expansion
vessel
Pressure
relief
Solar pumping station
Min. 250mm
Y Plan Sealed Primary Heating System Including Solar Input
Auxiliary
central
heating
Solar
controller
Expansion
vessel
Pressure
relief
Solar pumping station
Sealed
system
kit
INSTALLATION INSTALLATION
TORRENT STAINLESS SOL TORRENT STAINLESS SOL
Solar heating circuit
The Torrent Stainless SOL is an advanced
thermal store and has been designed to
incorporate existing boiler and central heating
controls and is based on the tried and tested
standard Torrent Stainless range. Therefore
general design requirements for hot and cold
water systems, for ball valve and overflow, for
water treatment and for heating system design
should be taken into account when designing
the Torrent Stainless SOL based systems.
The diagram opposite shows the Torrent
Stainless SOL type used in a traditional open
vented heating system. The water level in the
F&E tank should be at least 250mm above
the highest point of the heating system e.g.
a radiator.
In the open vented system shown opposite,
the thermal store, radiator heating circuit and
the auxilliary heating circuit are all fed from
the same feed and expansion tank. Therefore it
should be sized to accommodate the expansion
of total water content of the complete system
(i.e. water content of the store + water content
of radiator heating c water content of
under-floor heating circuit).
The diagram opposite shows the sealed primary
‘SP’ variant of the Torrent Stainless SOL used
in a typical sealed heating system. With this
system arrangement, although the boiler and
the radiator central heating circuits are sealed,
both the store and the auxilliary heating circuit
(if installed) are open vented. Therefore the
feed and expansion tank should be sized to
accommodate the expansion of total water
content of the open vented system (i.e. water
content of the store + water content of under-
floor heating circuit).
The diagrams also show typical configurations
of a solar thermal system with Torrent Stainless
SOL, which will accumulate the energy from
more than one renewable energy sources (e.g.
solar, wood burning stove).
In the open vented system, this energy is
available for hot water and at low level for both
radiator and under-floor (if installed) space
heating circuits. However in the sealed primary
system configuration, this energy is only
available for hot water and at low levels for the
under-floor space heating circuit (if installed).
For maximising the use of the renewable ‘green’ energy, the system should be managed
and controlled so that unnecessary firing of the boiler is kept to a minimum. This can be
achieved by a combination of householder use of the system and controls, for example;
Use the store to provide shower or a bath to utilise the heat gained by the system
from the previous day’s solar energy input. Alternatively showering or bathing in the
evening will utilise the energy that has been stored during the day from the solar
system.
• As with any system, hot water and space heating should be programmed according
to house holder requirements. However it is always good to remember that to gain
maximum advantage from the solar panels, the store should be as cool as possible,
prior to expected periods of high solar gain. To achieve this in spring, summer and
autumn, the hot water channel of the boiler should be programmed to come on 30
minutes before the hot water is required in the morning and then programmed off
before volumes of water are drawn off the system. This way the store is depleted
of heat allowing maximum transfer from the solar system during the day.
• However further supplementary time periods for the boiler will be required in
winter when not much solar energy is available.
• Uncontrolled boiler operation can also be reduced by fitting and wiring a pipe
thermostat on the solar return pipe close to the Torrent Stainless SOL.
As part of setup and commissioning, it is important that this boiler hold-off pipe
thermostat be adjusted to find the best setting for each individual installation.
Failure to do so will give under performance of either the boiler or the solar heating
system.
A solid fuel boiler can also be connected to the Torrent Stainless SOL, please refer to
page 19 for further information.
Domestic overheat protection
To comply with building regulations the solar overheat thermostat should be set at
a temperature which prevents the contents of the thermal store exceeding 100°C.
The DHW production board does not incorporate an overheat function, linked to the
primary store temperature, which would prevent it from running when this exceeds
80°C. The DHW temperature and flow rate are measured accurately and virtually
instantaneously by the HUBA flow sensor. The software algorithm is therefore enabled
to react virtually instantaneously to raised DHW temperatures.
The PWM pump flow rate will be reducing as the DHW temperature rises above 60°C
and fully stopped if the sensed DHW reaches 80°C. Thereby, the Torrent Stainless DHW
production is limited to 80°C in normal operating conditions, and does not need an
inline hot water tempering valve to limit the domestic hot water system to 60°C (see
part G para 3.64). However, this does not remove the obligation on the installer to
observe building regulations and water supply regulations recommendations.
In any installation, the hot water supply to a bath should be limited to 48°C by the use of
an inline blending valve (see part G para 3.65). In addition, the Water supply regulations
1999 (WRAS) recommends thermostatically controlled mixers should be used in all
installations, particularly where children in schools or aged or disabled people are
using showers in public buildings and are unsupervised. (see R18.5 section 8 page 9).