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INSTALLATION
INSTALLATION
INSTALLATION
TORRENT GREENHEAT OV
Boiler Size
The minimum total boiler power required is the
sum of the power required for space heating
which should be calculated in accordance with
BS EN 12831 and/or the CIBSE guide and the
power required for producing hot water which
can be read from the table to the left.
Expansion Vessel For Sealed Heating System
The table opposite can be used for sizing the
heating system expansion vessel. The water
content of the Torrent primary heat exchanger
is listed in specification tables on pages 6
and 7 and a figure of 4.5 l/kW of installed
radiator capacity can be used for a preliminary
assessment of the water content of the heating
system.
The expansion vessel requirements shown in
the table are based on a maximum boiler flow
temperature of 93°C. The expansion vessel
must be suitable to accommodate the change
in volume of water in the heating system when
heated from 10°C to 110°C.
Feed And Expansion Tank For Open Vented
Heating System
The potential expansion of all the thermal stores
in the range is shown in the table opposite,
alongside the capacity for expansion, in our
standard F & E tank, which can be supplied as
an optional extra.
Expansion for all other open vented systems
connected to the store must be added to this
figure. So, as a preliminary assessment of the
water content of the attached open vented
systems, a figure of 4.5 l/kW of radiator output
can be used. For example, 20 kW radiator output
would have a system volume of 90 litres, and
potential expansion of this would be 3.6 litres,
and 10 kW would be 45 litres total volume and
1.8 litres for expansion.
Please refer to page 26 for further information
regarding F&E tanks when using solid fuel input.
Allowance for domestic hot water for sizing the boiler
Torrent model
Allowance for domestic
hot water heating (kW)
Full divert mode
Flow share mode
140
0
2
170
0
3
210
0
3.5
280
0
4.5
350
0
6.0
450
0
8.0
Open vented heating systems
The open vented primary system is filled via the
feed and expansion (F&E) tank fitted with the
Torrent OV model and therefore it is important that
the F&E tank is positioned at least 250mm above
the highest point in the system. Please check
the F&E tank is big enough for the whole system
expansion. Also ensure that the height of the
F&E tank is sufficient to meet the manufacturer’s
requirements for the minimum head required for
the boiler and the system pump(s).
The Torrent OV models can be installed using
both ‘Y’ Plan and ‘S’ Plan heating system controls.
These models can also be installed without either
3-port or 2-port valves using a separate central
heating pump as shown in diagrams on this
page. In this case no bypass valve is required
unless TRV’s are used on all radiators.
If the flow and return pipes between the boiler
and the Torrent OV thermal store are dipped
as illustrated in the schematic shown opposite,
then the boiler selected must be suitable for a
sealed heating system i.e. it must be fitted with
an overheat thermostat. Automatic air vents
should be fitted at appropriate places to vent
the system and a pressure relief valve should
also be fitted close to the boiler.
Any boiler can be used with the Torrent OV and
the Torrent SOL provided the flow pipe from the
boiler to the Torrent is continuously rising. The
flow pipe between the boiler and the Torrent
thermal store is part of the open vent and
therefore it must not be fitted with any isolating
valve, non-return valve or any other component
which can obstruct the flow.
The minimum size of flow and return pipe
between the boiler and the Torrent should be
22mm copper or equivalent. In any case it should
be sized to suit the installed boiler capacity,
available pump head and the circuit resistance.
The water level must be set correctly by adjusting
the ball valve in the F&E tank. The overflow/
warning pipe, should be no less than the 20mm
internal diameter and have a continuous fall.
The overflow/warning pipe should be fitted to
discharge clear of the building and be sited so
that any overflow can be easily observed. The
warning pipe should be installed in either high
temperature uPVC or copper and should not
have any other connections to it.
If the boiler does not incorporate an overheat
thermostat, then one should be fitted to the store.
Expansion Vessel Requirements
Safety valve setting
3.0
Vessel charge
pressure (bar)
0.5
1.0
1.5
Initial system charge
pressure (bar)
0.5
1.0
1.5
2.0
1.0
1.5
2.0
1.5
2.0
Total System
Volume (litres)
Expansion Vessel Volume (litres)
25
2.1
3.5
6.5
13.7
2.7
4.7
10.3
3.9
8.3
50
4.2
7.0
12.9
27.5
5.4
9.5
20.6
7.8
16.5
75
6.3
10.5
19.4
41.3
8.2
14.2
30.9
11.7
24.8
100
8.4
14.0
25.9
55.1
10.9
19.0
41.2
15.6
33.1
125
10.4
17.5
32.4
68.3
13.6
23.7
51.5
19.5
41.3
150
12.5
21.0
38.8
82.6
16.3
28.5
61.8
23.4
49.6
Thermal Store
Potential
Expansion of
Water in Store
(litres)
Minimum Number of Feed and
Expansion Tanks
(16 litre model inc. 10 litre expansion)
TGH140
OV model - 6.6
SP model - 6.6
1
TGH170
OV model - 7.0
SP model - 7.0
1
TGH210
OV model - 9.6
SP model - 9.5
SOL model - 8.0
1
TGH250
OV model - 10.6
SP model - 10.1
SOL model - 11.1
2
TGH350
OV model - 16.5
SP model - 16.3
SOL model - 16.4
2
TGH450
SOL model - 21
3
Expansion of all connected open vented systems must be added to the store
expansion when choosing the size of the feed and expansion tank.
The weight of each tank when full is 27kg (not including pipework and valves).
2 Pump System
Max.
height
10m
Min. 250mm
2 Pump System With Dipped Boiler Flow and Return Pipe
Must comply
with boiler
manufacturer
instructions
Min. 250mm
