Section 1: Introduction
Page 4
1.1 GENERAL
The Grant Combined volumiser/low loss header provides the
functions of both a volumiser and low loss header in one unit,
with an integral 3kW electric immersion heater, for use with Grant
Aerona³ air source heat pumps.
As a volumiser it provides an extra 11.5 litres to the system
volume connected to the heat pump.
As a low loss header it gives hydraulic separation of the primary
circuit of the heat pump from the secondary system circuit. This
allows the flow rate through the heat pump to be maintained
irrespective of the different temperatures and flow rate in the
secondary system circuit.
The factory-fitted 3kW electric immersion element provides a
supplementary heat source, if required. Refer to Section 4 for full
details on the electrical connections for the immersion heater.
The Grant Combined volumiser/low loss header also provides
a means for connection two Aerona³ heat pumps to be used
together on the same system. Whether one or two heat pumps
are used, they can be connected to either the right-hand or
left-hand side of the volumiser/header. However, if two heat
pumps are used, they must both be connected to the same side.
Refer to Sections 3.7 and 3.8 for further information of heat pump
and system connections.
The Grant Combined volumiser/ low loss header can be used as
a volumiser only, either using the factory-fitted electric immersion
heater to provide a supplementary heat source or not, as required.
The Combined volumiser/low loss header is larger than normal for
a low loss header (e.g. 50mm, 75mm or 100mm diameter). This is
for two reasons:
a) To accommodate the 3kW immersion heater to provide a
supplementary heat source.
b) To minimise the internal turbulence that would normally
occur when the system mass flow of water exceeds that for
the primary heat pump circuit.
1 INTRODUCTION
Figure 1-1:
Grant Combined volumiser/low loss header
1.2 CONSTRUCTION
The Grant Combined volumiser/low loss header is an insulated
rectangular tank fitted with an integral 3kW electric immersion
heater. This is housed within a weatherproof external casing with
a removable cover at the top to access the electrical connections
and immersion heater.
It is designed to be located internally, fixed to a wall using the
mounting brackets on the header.
The volumiser/header tank is a mild steel welded construction,
insulated with mineral wool, enclosed within an outer galvanised
steel casing with a white powder coated paint finish.
It has two groups of three pipe connections located on the
left-hand side of the unit and two groups of two pipe connections
on the right-hand side. All of these are 1” BSPF connections, refer
to Section 2 – Technical Data for further details on dimensions.
The unit is supplied with a manual air vent, to allow the volumiser/
header to be vented following filling, and a ½” drain cock, to allow
it to be drained down if required. Both are supplied loose to be
fitted on site to their respective connections provided on the
right-hand side of the unit.
The 3kW electric immersion element is supplied, factory fitted and
located inside a removable panel on the top of the unit. This can
be used provide a backup heat source, if required, controlled by
the Grant Aerona air source heat pump to which it is connected.
Refer to Section 4 – Electrical.
! WARNING !
The immersion heater must NOT be used unless it is fully
immersed in water, i.e. the volumiser/header is completely
filled and vented.
Always ensure that the electrical supply to the immersion
heater is isolated BEFORE draining down the volumiser/
header.
Also, ensure that volumiser/header is fully refilled with
water and vented BEFORE switching the electrical supply
back on.
1.3
PRODUCT CONTENTS
The Grant Combined volumiser/low loss header is supplied with
the following items in a plastic bag located inside the top cover:
•
1 off ¼” manual air vent
•
1 off ½” drain cock
•
1 off 3/8” x ¼” reducing bush
•
4 off 1” blanking plugs
The following items are also supplied with the volumiser/header:
•
2 off 28mm isolating valves
•
1 off Installation instructions.
