Panasonic Aquarea Tank Duo GH 200 Design, Installation & Servicing Instructions page 15

Safety Valve
Heat Pump
Heating And Primary Systems
Although the heat pump and the primary heating system should be sized and installed
in accordance with BS EN 12828:2003, BS EN 12831:2003 & BS EN 14336:2004 the
following should also be taken into account during the design and installation phase.
The heat pumps normally operate at lower flow temperatures; typically 45 – 55°C
compared with 75 – 80°C for the boilers. Therefore if traditional radiators are used
then, these should be oversized in accordance with the heat pump manufacturers
recommendations. For optimum efficiency (i.e. COP of a heat pump), low temperature
under floor heating system should be considered.
The heat pumps normally operate at lower temperature difference between flow and
return compared with the traditional boilers and therefore when sizing the pipework
heat pump manufacturers recommendations should be taken into account.
Safety
Aquarea Duo cylinder is fitted with a combined temperature and pressure relief valve
to cope with any increase in temperature and pressure in the cylinder above the design
limits, when used with heat sources up to 45kW total output.
The 3 port spring return motorised valve supplied fitted on the flow from the heat
pump unit. The heat pump remote control unit sets the position of the valve to either
cylinder charging (port A) or central heating (port B). Power is supplied to the 3 port
valve when in cylinder charging mode. Therefore the cylinder cannot be heated if
there is no power to the valve.
The cylinder (tank) sensor sends accurate temperature information to the remote
control unit, this information coupled with the program times, controls the cylinder
charging. If the cylinder is not heated quickly enough the Boost immersion heater
will function automatically. Once the tank temperature has exceeded the tank set
temperature by 2° the valve will be closed.
The Boost immersion heater has its own controls to prevent it overheating the cylinder.
• Sealed heating system
A heat pump selected must be suitable for use in a sealed heating system which
may have working pressure of up to 3.0bar and it must be fitted with an overheat
temperature cut-out device.
Schematic Sealed Primary System
Expansion
Vessel
Gauge
INSTALLATION
Page 15
Unvented (i.e. sealed primary circuits may
be filled or replenished by means of a
temporary connection between the circuit
and a water supply pipe provided a WRC
'Listed' double check valve and filling loop
or some other no less effective backflow
prevention device is permanently connected
at the inlet to the circuit and the temporary
connection is removed after use. This is
supplied fitted with the pre-plumbed unit.
Alternatively, a CA device can be used which
will allow the system to be permanently
connected to the cold mains supply. The
primary system can then be topped up,
when required, in the same way as an open
vented system fitted with an F&E cistern.
INSTALLATION