gledhill Torrent GreenHeat OV TGH140 Design, Installation & Servicing Instructions page 7

DESIGN
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Typical arrangement of tappings shown on the appliance, but these can be
adjusted to suit speci c installation requirements.
The feed and expansion tank must be sized to take the water expansion of the
whole system (i.e. solid fuel boiler, open vented boiler and auxiliary heating).
SYSTEM DESIGN
Torrent GreenHeat HP
Basic Appliance
1
1. Open vent - 22mm comp (450 - 28mm comp)
3
2. Store overheat - 1/2" female
3. Plate heat exchanger ow - 22mm
4
4. Domestic hot water store sensor
5. Hot water supply - 22mm comp
6. Solid fuel ow - 28mm comp
7. Heat pump cylinder sensor
8. Limit stat - 1/2" female
9. Cold mains supply - 22mm comp
10. DHW backup immersion heater
11. Heat pump ow - 28mm comp (350/450 1.25 Fem)
12. Central heating ow - 22mm comp
13. Domestic hot water store sensor
5
14. Cold feed - 15mm comp
15. CH boost immersion heater
16. Central heating return - 22mm comp
17. Heat pump return sensor
18. Heat pump return - 28mm comp (350/450 1.25 Fem)
19. Solid fuel return - 28mm comp
20. Plate heat exchanger return - 22mm
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21. Drain - 1/2" female
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Component kit supplied attached
A. Thermostat
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15
B. Immersion heater
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Optional extra components
A. Header tank
B. Ball valve
C. Float
D. Overheat thermostat
E. Solid fuel tappings
F. Scale inhibitor
Torrent GreenHeat HP SOL
Basic Appliance
1
1. Open vent - 22mm comp (450 - 28mm comp)
2. Overheat stat - 1/2" female
3
3. Plate heat exchanger ow - 22mm
4
4. Domestic hot water store sensor
5. Solar sensor
6. Solid fuel ow - 28mm comp
7. Heat pump cylinder sensor
8. Limit stat - 1/2" female
5
9. Hot water supply - 22mm comp
10. DHW backup immersion heater
11. Heat pump ow sensor
12. Heat pump ow - 28mm comp (350/450 1.25 Fem)
13. Central heating ow - 22mm comp
9
14. CH boost immersion heater
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15. Central heating return - 22mm comp
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16. Heat pump return sensor
17. Heat pump return - 28mm comp (350/450 1.25 Fem)
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18. Solid fuel return - 28mm comp
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19. Solar coil ow - 22mm comp (450 - 28mm comp)
20. Cold mains supply - 22mm comp
20
21. Solar sensor
21 22. Cold feed - 15mm comp
23. Solar coil return - 22mm comp (450 - 28mm comp)
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24. Solid fuel return - 28mm comp
25. Plate heat exchanger return - 22mm
25 26. Drain - 1/2" female
Component kit supplied attached
A. Thermostat
B. Immersion heater
Optional extra components
A. Header tank
B. Ball valve
C. Float
D. Overheat thermostat
E. Solid fuel tappings
F. Scale inhibitor
Page 12
General
• All Torrent GreenHeat HP models covered by this manual, are only suitable for open
vented primary (heat pump and space heating) circuits. Therefore the pressure
in the primary circuit depends upon the height of the feed and expansion cistern
and could be as low as 0.20 bar. Therefore ensure that the heat pump selected
will operate at primary circuit pressures e.g. it is not tted with a non-adjustable
low system pressure switch.
• The heat pumps normally operate at lower temperature difference (5-10°C)
between ow and return than that for a gas boilers (10-20°C) resulting in higher ow
rates in the heat pump primary circuit. Therefore it is important that the primary
pipework connecting the heat pump to the thermal store and the circulating pump
are sized to achieve ow rates recommended by the heat pump manufacturer.
• The e ciency (i.e. coe cient of performance, COP) of a heat pump depends
upon the primary ow and return temperatures and it is generally higher at lower
primary circuit temperatures. Also the heat pumps normally operate at lower ow
temperatures; typically 45-55°C compared with 75-80°C for gas boilers. Therefore if
traditional radiators are used then, these should be oversized in accordance with
the heat pump manufacturers recommendations.
• For optimum operational e ciency and hence lower running costs, a low temperature
space heating (e.g. under- oor heating) system should be used where feasible.
Hot water performance of TGH210HP at 15 - 17 l/min draw off rate
60
50
40
30
20
10
0
Draw-off volume (litres)
HW Outlet(75) (°C) HW Outlet (65) (°C) HW Outlet (55) (°C)
The draw o volume gures shown above are for the TGH210 HP store. These are
increased accordingly as the cylinder capacity increases. The graph illustrates the
increase in volume that can be achieved by the use of the auxiliary heat source.
A 15 - 17 litre/min ow restrictor is tted to the Torrent GreenHeat HP hot water supply
outlet on commissioning. Check that the hot water ow does not exceed 17 litre/min.
Particular attention needs to be paid to the product size selection. If the
intention is for the majority of the hot water to be provided by the heat
pump with minimal use of the auxiliary immersion element then it may
be necessary to choose a larger store.
DESIGN
Heat Pump Sizing
• The e ciency (i.e. coe cient of performance,
COP) of an air source heat pump and hence
its heat output generally decreases as
the ambient air temperature decreases.
Therefore, this factor should be taken into
account when sizing and selecting the heat
pump.
• The design space heating load of a dwelling
should be calculated in accordance with
BS EN 12831 and/or the CIBSE guide. The
allowance for domestic hot water heating
(shown in table below), depends upon
the operating mode. For example, if the
system is designed to operate with priority
for domestic hot water, then no additional
allowance for hot water is required for sizing
the heat pump.
Allowance for Domestic Hot Water
Heating
Allowance for Domestic
Hot Water
Torrent
Hot Water
Model
Priority
Mode
180 HP-SOL 0kW
180 HP
0kW
210 HP-SOL
210 HP
0kW
250 HP-SOL
250 HP
0kW
300 HP-SOL
350 HP
0kW
450 HP-SOL
450 HP-SOL 0kW
AVG CW Inlet Temp (°C)
SYSTEM DESIGN
Page 13
Flow Share
Mode
1.5kW
2.5kW
3.0kW
3.5kW
4.0kW
5.0kW