The Heat Pump - The Heart Of The House; Heat Pump Function - Nibe F730 User Manual

The heat pump – the heart of the
house

Heat pump function

This exhaust air heat pump uses the heat that is in the
house's ventilation air and in the outdoor air to heat up the
accommodation. The conversion of the air's energy to
heating occurs in three different circuits. Heating energy is
retrieved from the outgoing air (1) from the accommodation
and transferred to the heat pump. The heat pump increases
the recovered heat's low temperature to a high temperature
in the refrigerant circuit (2). The heat is distributed around
the house in the heating medium circuit (3).
1
22 °C
B
C
5 °C
2 Compressor
D
80 °C
55 °C
3
Ventilation air
Rumsluft
Refrigerant Köldmedium
Heating medium Värmebärare
Uteluft
Outdoor air
The temperatures are only examples and may vary between
different installations and time of year.
NIBE F730
A
0 °C
0 °C
Evaporator
Expansion valve
F
Condenser
E
G
45 °C
H
Ventilation air
A The hot air (exhaust air) is transferred from the rooms to the
heat pump via the house ventilation system. Outdoor air is
only when necessary.
B The fan then routes the air to the heat pump's evaporator.
Here, the air releases the thermal energy and the air's tem-
perature drops significantly. The cold air (extract air) is then
blown out of the house.
Refrigerant circuit
C A liquid, a refrigerant, circulates in a closed system in the
heat pump which also passes the evaporator. The refrigerant
has a very low boiling point. In the evaporator the refrigerant
receives the heat energy from the ventilation air and starts
to boil.
D The gas that is produced during boiling is routed into an
electrically powered compressor. When the gas is com-
pressed, the pressure increases and the gas's temperature
increases considerably, from approx. -5°C to approx. 100°C.
E From the compressor, the gas is forced into a heat exchanger,
condenser, where it releases heat energy to the heat pump's
heating section, whereupon the gas is cooled and condenses
to liquid form again.
F As the pressure is still high, the refrigerant can pass an ex-
pansion valve, where the pressure drops so that the refriger-
ant returns to its original temperature. The refrigerant has
now completed a full cycle. It is routed to the evaporator
again and the process is repeated.
Heat medium circuit
G The heat energy that the refrigerant produces in the condens-
er is retrieved by the climate system's water, heating medium,
which is heated to 55 °C (supply temperature).
H The heating medium circulates in a closed system and
transports the heated water's heat energy to the heat pump's
integrated hot water heater and the radiators/heating coils
of the house.
I The heat pump's integrated water heater is in the heating
section. The heating medium heats the hot water.
Chapter 2 | The heat pump – the heart of the house 7