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 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 VortexBlue 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. System models are supplied with the necessary
components factory fitted. Refer to Section 7.
All boilers are supplied with the control panel and burner factory
fitted.
All the models in the current Grant VortexBlue range of boilers are
designed to comply with the maximum NOx emissions* under the
Energy-related Products Directive (ErP).
* From the 26th September 2018, the maximum NOx emissions
for all new oil fired boilers (up to and including 400kW for both
new build and replacement boiler installations) is 120mg/kWh.
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 is required, Grant recommends
the use of the Grant ‘Hybrid’ flue system, which uses components
from the Grant ‘Orange’ and ‘Green’ flue systems. Refer to Figure
9-4 for details. This flue system is suitable for all Grant VortexBlue
oil boilers.
The ‘Orange’ system flue components used for the internal part of
the Hybrid system (extensions and elbows) are from the smaller
100mm size range (e.g. WE45/100 elbow, WX450/100 450mm
extension, etc.) – refer to Table 9-3.
The ‘Green’ system twin wall flue components used for the
external part of the Hybrid system are from the larger ‘200’ size
range (e.g. GTV/200B terminal, GX950/200B 950mm extension,
etc.) that have a 100mm internal flue diameter – refer to Table 9-5.
The Grant flue adaptor kit (Grant product code: CFA15/70) will
also be required as this contains:
a)
the flue adaptor required to connect the ‘Orange’ system
flue components to the boiler flue outlet (no flue adaptor is
supplied with the boiler).
b)
the adaptor to connect the single wall ‘Orange’ system flue to
the twin wall ‘Green’ system flue.
The maximum vertical height (from the top of the boiler to the
terminal) of the ‘Hybrid’ Green/Orange flue system is 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 kit - short and standard
lengths available
•
Extensions 225 mm, 450 mm and 675
mm (internal use only)
•
90° extension elbow (internal use only)
•
45° extension elbow (internal use only)
•
45° elbow (internal use only)
•
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 extension 275 to 450 mm
•
Vertical concentric balanced flue kit
•
45° elbow
Red system (for 21 and 26 models 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 stainless steel 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
