Operating Principle - Fujitsu Waterstage Split Comfort 5 Series Installation Manual

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Operating principle

The heat pump transmits the energy contained in the
surrounding air into the dwelling to be heated.
The heat pump consists of four main elements, in which
a refrigerant (R32) circulates
- In the evaporator (ref. 12,
The calories are taken from the outside air and
transmitted to the refrigerant. Because it has a low
boiling point, it changes from a liquid to a vapour, even
in cold weather (down to -25°C outside temperature).
- In the compressor (ref. 9,
The vaporised refrigerant is pressurised and takes on
even more calories.
- In the condenser (ref. 15,
The energy of the refrigerant is transmitted to the
heating circuit. The refrigerant returns to its liquid state.
- In the expansion valve (ref. 8,
The liquefi ed refrigerant is returned to a low pressure
and regains its initial temperature and pressure.
The heat pump is equipped with a controller which
controls the room temperature based on the outdoor
temperature measurement. The room thermostat
(option) provides a corrective action for the temperature
control.
The hydraulic unit is fi tted with an electrical backup* or
boiler connection* which intervenes to provide additional
heat during the coldest periods.
Dwelling heat loss (kW)
8
7
6
Backup
5
4
3
Heat Pump
2
1
0
-20 -15 -10 -5
Heat Pump +
Heat Pump only
electrical
backup
fi g. 10 - Examples and operating limits
- 14 -
fi g. 8, page
fi g. 8, page
fi g. 9, page
fi g. 8, page
Heat Pump power
0 5 10 15 20 25
Outdoor temperature (°C)
Max authorised
Heat Pump start-up temp.
Outdoor temperature (°C)
■ Control functions
- The heating circuit's fl ow temperature is controlled by
the temperature control.
- Depending
12) :
the outdoor unit's power is modulated by the "Inverter"
compressor.
- Control of the backup electrical heating.
- The daily timer program is used to set the periods
where the ambient temperature is comfortable or
12) :
reduced.
- Summer/winter time mode switchover is automatic.
- Management of the boiler backup*.
13) :
- Room sensor*: The room sensor provides a corrective
action for the temperature control.
- Control of a second heating circuit*.
12) :
- Domestic hot water: Heating timer program.
- Managing cooling*.
* Where the heat pump is fi tted with options and associated kits.
■ Protective functions
- Anti-legionella cycle for domestic hot water.
- Anti-corrosion tank protection with titanium anode
(ACI).
- Frost protection: Frost protection cuts in if the heating
circuit's fl ow temperature falls below 5°C (provided
that the heat pump's electrical power supply is not
interrupted).
46
Waterstage Split Comfort DHW Serie / INSTALLATION / 2125 - EN
on the heating fl ow temperature,