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Aquarea air-to-water heat pumps - Planning and installation manual - 02/2022
Product Description
4
4.4 Heat use
4.4.1 Heating
In contrast with heat sources with burners, which generate supply water temperatures of
over 80 °C, the maximum water outlet temperature of the Aquarea heat pump is limited to
60 °C (Aquarea High Performance J Generation) or 65 °C (Aquarea T-CAP J Generation and
Aquarea HT) without using the backup heater. This must be taken into consideration during the
planning of the heating circuits. Surface-embedded systems (i.e. underfloor, ceiling or wall heating)
that have a supply water temperature of up to 35 °C and a supply/return water temperature
difference (ΔT) of 5 K are recommended. An advantage of underfloor heating with wet screed
laying is its high storage capacity, which eliminates the need for a buffer tank for bridging power
cut-off times by the energy supply company.
Fan coils have the advantage of good heat emission to the ambient air with quick control
performance. Besides, they can be used for both the heating and cooling modes to the same
extent.
If radiators are used, plan with the lowest possible design temperature of, for example, 45 °C, to
ensure high efficiency of the heat pump system. An internal backup heater of 3 to 9 kW with its
mono-energetic operating mode ensures high heating comfort of the Aquarea heat pump even at
very low outside temperatures. Alternatively, a bivalent operation is also possible in combination
with an external heat source.
The Aquarea heat pump has an outside temperature-dependent control of the supply water
temperature and can thus actuate a heating circuit with a room thermostat. The other heating
circuits can be controlled through additional heating circuit controllers or a superordinate system
controller.
4.4.2 Domestic hot water production
The Aquarea heat pump can also produce domestic hot water (DHW), and this function is
integrated in the controls. It switches to this operating mode when necessary and systematically
actuates the tank for hot water production through a 3-way valve.
For reasons of efficiency, the hot water temperature is set to a value below 60 °C in heat pump
operation. A hot water temperature of 45 °C is normally sufficient and does not compromise comfort
in any way. If the hot water temperature is, however, too low, there is the risk of Legionella to be
considered; the growth of Legionella is particularly likely in water temperatures between 30 and
50 °C.
Panasonic hot water tanks are fitted with an electrical heating rod (DHW tank booster heater) for
comfortable hot water supply, which is only switched on when needed or for Legionella prophylaxis
(sterilisation).
Aquarea heat pumps can be easily combined without a problem with solar systems, which can take
over hot water production to a large extent in the summer.
