Fujitsu AOYA18LALL Installation And Operating Manual page 13

Heat pump, Split, single service
Domestic hot water (DHW) operating principle
Two domestic hot water (DHW) temperatures can be
parametered: comfort temperature (line 1610 to 60
°C) and reduced temperature (line 1612 to 40 °C).
Setting for reduced temperature can be useful to
prevent the DHW from switching on too often and for
too long during the day.
The production of domestic hot water (DHW) is
triggered when the temperature in the tank falls 7°C
(setting from line 5024) below the set temperature.
The heat pump produces the domestic hot water,
which is then supplemented, if required, by electrical
backup heating from the tank.
Depending on how the parameter (1620) is set,
comfort temperature can be reached 24h/day or only
at night or depending on the heat pump programme.
If the contract concluded with the energy provider
includes a subscription to day/night tariff, the
electrical backup is subordinate to the supplier's
power tariff and the comfort temperature may only be
reached at night.
Energy from the air
Installation and operating manual "1350-EN"
If no particular contract is concluded, the comfort
temperature can be reached at any time, including
during the day
The production of DHW takes priority over heating;
nevertheless the production of DHW is controlled by
cycles that control the times assigned to the heating
and the production of DHW in the event of
simultaneous demand.
A DHW " boost" function is available on the front of
the user interface (see ref. 1, fig. 39, p 31).
This DHW boost enables the DHW to be heated to
the comfort temperature at any time during the day.
The boost function is cancelled automatically when
the demand for hot water has been met.
If the heating installation is equipped with a DHW
circulation pump, the pump's operation during DHW
cycles can be parametered.
Anti-legionella cycles can be programmed.
Dt
Ev
Cp
Electrical
energy
consumed
Figure 9 - Heat pump operating principle
PAC
4 kW
Cn
Heat produced Heat produced
COP 4
1 kW
20 °C
PAC - Heat pump
Ev - Evaporator
Cp - Compressor
Cn - Condenser
Dt - Expansion valve
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