1Introduction
4
Introduction
This manual is intended to guide
engineers in the installation and
maintenance of Grant VORTEX Eco
External Wall Hung boilers. A User
Guide for the operation of this boiler is
attached to the reverse of this manual.
The following special text formats are
used in this manual for the purposes
listed below:
Warning of possible human injury as
a consequence of not following the
instructions in the warning.
1.1 How a Condensing
Boiler Works
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 Eco External Wall
Hung 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 Eco External Wall
Hung 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 Vortex Eco External Modules have
an insulated weatherproof enclosure
made of galvanised steel with a powder
coated finish, and are designed for
external installation, Mounted on a
suitable external wall.
The Grant VORTEX Eco External
modules are part of the Grant range of
automatic pressure jet oil boilers, and
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. All models are supplied with
the control panel and burner factory
fitted.
The boilers are supplied with a flue
terminal, but can be connected to a
conventional flue system.
An external conventional flue (Green)
system is available from Grant
Engineering (UK) Ltd. Refer to Chapter 9
for further details including the list of
available components of this system.
A hybrid flue (Green/Orange) system is
also available which allows the External
module to utilize an existing chimney
stack. Refer to Chapter 9 for further
detail including the list of available
components of this system.
Caution concerning likely damage to
equipment or tools as a
consequence of not following the
instructions in the caution.
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 warranty on
the boiler.
Note text. Used for emphasis or
information not directly concerned
with the surrounding text but of
importance to the reader.
!WARNING
!CAUTION
!NOTE
!NOTE
