Section 1: introduction
page 4
1.1 HOW a CONDENSiNG BOiLER
OpERatES
During the combustion process, hydrogen and oxygen combine
to produce heat and water vapour. The water vapour produced
is in the form of superheated steam in the heat exchanger. This
superheated steam contains sensible heat (available heat) and
latent heat (heat locked up in the flue gas). A conventional boiler
cannot recover any of the latent heat and this energy is lost to the
atmosphere through the flue.
The Grant Vortex condensing boiler contains an extra heat
exchanger which is designed to recover the latent heat normally
lost by a conventional boiler. It does this by cooling the flue gases
to below 90°C, thus extracting more sensible heat and some of
the latent heat. This is achieved by cooling the flue gases to their
dew point (approximately 55°C).
To ensure maximum efficiency, the boiler return temperature
should be 55°C or less, this will enable the latent heat to be
condensed out of the flue gases.
•
The boiler will achieve net thermal efficiencies of 100%.
To achieve maximum performance from the Grant Vortex boiler,
it is recommended that the heating system is designed so that a
temperature differential of 20°C between the flow and return is
maintained. The use of modulating circulating pumps (now widely
available) and effective control systems should be considered.
The Grant Vortex boiler will however still operate at extremely
high efficiencies even when it is not in condensing mode and
therefore is suitable for fitting to an existing heating system
without alteration to the radiator sizes. The boiler is capable of a
maximum flow temperature of 75°C.
1.2 BOiLER DESCRiptiON
The Grant Vortex Boiler House range of automatic pressure jet oil
boilers have been designed for use with a fully pumped central
heating system with indirect domestic hot water cylinder.
They are not suitable for use with either a direct cylinder or a
‘primatic’ cylinder or gravity hot water.
The boilers are suitable for use on open vented or sealed central
heating systems.
The boilers are supplied with a separate burner and dual
thermostat (15/21, 21/26, 26/35 and 36/46 models only).
The dual thermostat is supplied factory fitted on the 46/58, 58/70
models.
1.3 FLUE OptiONS
The boilers can be connected to either a conventional flue system
or a balanced flue system, as required.
1.3.1 FOR CONVENtiONaL FLUE appLiCatiONS
Where a chimney is to be lined - Grant recommends the use
of the Grant ‘Orange’ flue system, specifically designed for the
Vortex range of condensing boilers. Refer to Section 9.2 for
further details.
Where a rigid conventional flue - either internal or external - is
required, Grant recommends the use of the Grant ‘Green’ and
‘Orange’ flue system components. As no flue adaptor is supplied
with the boiler it will be necessary to purchase the Grant CF
adaptor kit in order to correctly connect this system to the boiler.
Flue adaptor kit (Grant product code: CFA15/70) is used for all
models as they all use the 100 mm ‘Green’ and ‘Orange’ system
components to construct a flue of maximum vertical height 19
metres.
! NOtE !
The flue system materials and construction MUST be
suitable for use with oil-fired condensing boilers. Failure
to fit a suitable conventional flue may invalidate the
guarantee on the boiler.
1.3.2 FOR BaLaNCED FLUE appLiCatiONS
The following flue kits are available from Grant UK. Refer to
Section 9.4.
Yellow system
Standard low level concentric balanced flue - components
available:
•
Low level concentric balanced flue short
•
Extensions 225 mm, 450 mm and 675
mm
•
90° extension elbow
•
45° extension elbow
•
45° elbow
•
Plume diverter kits
Green system
Standard external high level/vertical flue starter kit (room sealed) -
components available:
•
External high level/vertical flue starter kit short (room sealed)
•
Extensions 150 mm, 250 mm, 450 mm, 950 mm
•
Adjustable extension 195 to 270 mm
•
45° elbow
•
High level terminal
•
Vertical terminal
White system
High level and vertical concentric balanced flue kit- components
available:
•
Extensions 225 mm, 450 mm, 950 mm
•
Adjustable 275 to 450 mm
•
Vertical concentric balanced flue kit
•
Extensions 225 mm, 450 mm, 950 mm
•
Adjustable extension 275 to 450 mm
•
45° elbow
Red system (15/21 and 21/26 only)
A flexible vertical balanced flue system designed to be fitted inside
an existing masonry chimney.
Consisting of three sections:
• Concentric white painted flue pipe connected to the boiler
• Vertical concentric flexible flue (flexible stainless steel flue liner
inside a flexible plastic air inlet liner)
• Terminal assembly for chimney top mounting
Flue extensions and 45° elbows from the White system may be
used.
Fitting instructions for the Low level, High level and Vertical
balanced flue systems are supplied with the kits.
1 iNtRODUCtiON
Содержание Vortex VTXBH1521
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