2
Purpose of the Heat
Pump
2.1 Application
The air-to-water heat pump is to be used exclusively for the hea-
ting of heating water. It can be used in newly built or previously
existing heating systems.
The heat pump is suitable for both mono-energetic and bivalent
operation at outdoor temperatures down to -25 °C.
In the continuous mode of operation, a heating water return tem-
perature of more than 18 °C or 20 °C (see operating temperature
limits in the Appendix) must be maintained in order to assure pro-
per defrosting of the evaporator.
The heat pump is not designed for any increased heat demand
during the drying phase of new buildings; the additional heat de-
mand must be met by special appliances to be supplied on site.
For the structural drying of new buildings in the autumn or winter
it is recommended that an additional electric heating element
(available as accessory) be installed.
ATTENTION!
The appliance is not suited for frequency converter operation.
2.2 Principle of Operation
Ambient air is drawn in by the fan and passed over the evapora-
tor (heat exchanger). The evaporator cools the air, i.e. it extracts
the heat it contains. In the evaporator, the heat removed is trans-
ferred to the working fluid (refrigerant).
With the aid of an electrically driven compressor, the absorbed
heat is "pumped" to a higher temperature level through an incre-
ase in pressure and given off to the heating water via the conden-
ser (heat exchanger).
In so doing, the electrical energy is used to raise the heat of the
environment to a higher temperature level. Due to the fact that
the heat energy extracted from the air is transferred to the hea-
ting water, this type of appliance is referred to as an air-to-water
heat pump.
The air-to-water heat pump consists of the following main com-
ponents: Evaporator, fan and expansion valve as well as the low-
noise compressor, the condenser and the electric control unit.
In the case of low ambient temperatures, air humidity may accu-
mulate on the evaporator in the form of frost impairing the heat
transfer. The evaporator is automatically defrosted by the heat
pump, as required, with the possibility of vapour plumes forming
at the air outlet, depending on the weather.
3
Scope of Delivery
3.1 Baseline Unit
The heat pump is delivered as a compact unit containing the
components listed below.
The refrigerant circuit is hermetically sealed. It contains the
Kyoto protocol approved fluorinated refrigerant R404A with a
GWP value of 3260. It is CFC-free, non-ozone depleting and
non-combustible.
1)
Evaporator
2)
Check valve
3)
Fan
4)
Control box
5)
Pressostats
6)
Filter-drier
7)
Condenser
8)
Expansion valve
9)
Compressor
3.2 Control Box
The control box is integrated in the heat pump. It can be folded
downward after removing the lower front panel and loosening the
fastening screws located at the top on the right.
The control box houses the mains terminals as well as the power
contactors and the soft start unit.
The plug connector for the control lead is located at the bottom of
the unit in the immediate vicinity of the line feed-through through
the bottom of the unit.
3.2
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