Purpose Of The Heat Pump; Application; Operating Principle; Scope Of Supply - Dimplex LAJ 11MUR Installation And Operating Instructions Manual

2 Purpose of the heat
pump

2.1 Application

The air-to-water heat pump is to be used exclusively for the heat-
ing and cooling of heating water. It can be used in new or existing
heating systems.
In heating operation, the heat pump is suitable for mono energy
and bivalent operation down to an external temperature of -
20 °C.
During continuous operation, proper defrosting of the evaporator
must be guaranteed by maintaining a heating water return
temperature of more than 18 °C.
The heat pump is not designed for the increased heat consump-
tion required when a building is being dried out. For this reason,
the additional heat consumption should be met using special de-
vices provided by the customer. If a building is to be dried out in
autumn or winter, we recommend installing an additional electric
heating element (available as an accessory).
In cooling operation, the heat pump is suitable for air tem-
peratures ranging from +15 °C to +35 °C).
It can be used for silent and dynamic cooling.
NOTE
The device is not suitable for operation with a frequency converter.

2.2 Operating principle

Heating
Surrounding air is drawn in by the ventilator and fed through the
evaporator (heat exchanger). The evaporator cools the air, i.e.
extracts heat from it. This extracted heat is then transferred to the
working medium (refrigerant) in the evaporator.
The heat is brought to a higher temperature level by increasing
its pressure with the aid of an electrically driven compressor. It is
then transferred to the heating water via the liquefier (heat ex-
changer).
Electrical energy is used to raise the temperature of the heat
from the environment to a higher level. Because the energy ex-
tracted from the air is transferred to the heating water, this type
of device is referred to as an air-to-water heat pump.
The main components of an air-to-water heat pump are the evap-
orator, ventilator and expansion valve, as well as the low-noise
compressor, liquefier and the electrical control system.
At low ambient temperatures, humidity accumulates on the evap-
orator in the form of frost, reducing the transfer of heat. Uneven
accumulation during this process does not indicate a fault. The
evaporator is defrosted automatically by the heat pump as re-
quired. Under certain atmospheric conditions, steam may be
emitted from the air outlet.
www.dimplex.de
Cooling
The functions of the evaporator and the liquefier are reversed in
the "Cooling" operating mode.
The heating water transfers its heat to the refrigerant via the liq-
uefier, which is now functioning as an evaporator. The refrigerant
is brought to a higher temperature level using the compressor.
Heat is transferred to the surrounding air via the liquefier (which,
in heating operation, functions as an evaporator).
3

Scope of supply

3.1 Basic device

The heat pump contains the components listed below.
The refrigerating circuit is "hermetically sealed" and contains the
Kyoto protocol-approved refrigerant R404A with a GWP value of
3784. It is CFC-free, does not deplete ozone and is non-flamma-
ble.
1) Evaporator (heating operation)
2) Fan
3)

Switch box

4) Liquefier (heating operation)
5) Compressor
3.2 Switch box
The switch box is located in the heat pump. It can be swung out
after removing the lower front cover and loosening the fastening
screw located in the upper right-hand corner.
The switch box contains the supply connection terminals, the
power contactors and the soft starter unit.
The plug connector for the control line is located on the base of
the device, immediately adjacent to the cable gland in the base-
plate.
452159.66.37 · FD 9311
LAJ 11 MUR - LAJ 16 MUR
EN-3