Description; General Information; Refrigerant Circuit (Heat Pump Operating Principle); Safety And Control Devices - Dimplex BWP 30 HMW Instructions D'installation Et D'utilisation

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Description

2.1 General Information

The hot-water heat pump is a ready-to-use heating device and
mainly consists of hot water cylinders, the components for the re-
frigerant, air and water circuits, as well as all of the control, regu-
lation and monitoring devices required for automatic operation.
Using electrical energy, the hot-water heat pump heats water
using the heat stored in the air which is sucked in. The hot-water
heat pump with internal heat exchanger can be connected to ad-
ditional heat generators such as heat boilers or solar installa-
tions. A vertical cladding tube (inner ∅ ≥ 12 mm) houses an ex-
ternal temperature sensor. The devices are standard equipped
with an electric heating element (1.5 kW).
The temperature of the air sucked in (the heat source) is used as
reference value for energy consumption and DHW preparation
heat-up time.
For this reason, an air duct system (DN 160, max. length 10 m)
can be connected to the standard spigot of the hot-water heat
pump for specific waste heat recovery. In principle, effective op-
eration of the heat pump requires that there is no air short-circuit
between the air that is sucked in and the air that is blown out.
This can, for example, be achieved by a flexible air hose on the
intake and outlet side.
Falling outlet air temperatures reduce heat pump performance
and increase heat-up time. Air inlet temperature should not fall
below 15 °C for economical heat pump operation. If the air inlet
temperature falls below 8 °C ±1.5 (dead-band value 3 K), the
heat pump is switched off and the DHW is heated by the stand-
ard heating element (1.5 kW).
The electric heating element fulfils four functions:
Supplementary heating
The heating-up period is approx. halved by switching on the
heating element (using the "Heating Element" switch, see
Point 2.3) in addition to the heat pump.
Frost protection
If the air temperature falls below 8 ±1,5 °C (dead-band value
3 K), the electric heating element switches on automatically
and (nominally) heats the water up to the set hot water tem-
perature. The hot-water temperature generated by the heat-
ing element in antifreeze mode can exceed the set value!
Emergency heating
The water supply is maintained by the electric heating ele-
ment if the heat pump is out of order.
Higher water temperature
If the required hot water temperature is higher than the tem-
perature achievable by the heat pump (approx. 60 °C), it can
be raised to a max. of 85 °C by using the heating element.
ATTENTION!
When the hot water temperature reaches > 60 °C, the heat pump switches
off and the hot water is heated solely by the heating element. The heating
element controller is factory set to 65 °C.
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2.2 Refrigerant Circuit (Heat Pump
Operating Principle)
The refrigerant circuit is a closed-loop system in which the refrig-
erant R134a is the energy source. The finned heat exchanger ex-
tracts heat from the air sucked in at a low evaporation tempera-
ture, and transfers it to the refrigerant. The vaporous refrigerant
is sucked in by a compressor where it is compressed to a higher
pressure and temperature level before being transported to the
liquifier, where the heat taken up in the evaporator and part of the
compressing energy is transferred to the water. Subsequently,
the high condensation pressure is lowered to the evaporation
pressure via a throttle mechanism (expansion valve). In the
evaporator, the refrigerant will again take up heat from the air
that is sucked in.

2.3 Safety and Control Devices

The hot-water heat pump has the following safety features:
High-pressure switch
The high-pressure switch protects the heat pump against imper-
missibly high operating pressure in the refrigerant circuit. In the
event of fault, the pressure switch will switch off the heat pump.
The heat pump is restarted automatically if there has been a
pressure drop in the refrigerant circuit.
Safety temperature limiter for heating element
(STL)
The STL protects the hot-water installation against impermissible
temperature increases.
The heating element is switched off if the set switching value
(99 °C) is exceeded.
The heating element cannot be re-started until the hot-water tem-
perature has decreased to ≤ 90 °C and the reset button (see il-
lustration) on the STL is pressed (this may be done by qualified
personnel only).
The hot-water heat pump is equipped with the following regula-
tion and control devices:
2.3
EN-3