REMKO WKF 120 Duo - Manual (Page 26)

Thanks to innovative inverter technology, this
heat pump will almost always operate by
adapting its heating capacity to the actual
requirements of the heating season, and will in
fact turn itself off when heat is no longer
needed. The same applies in the opposite
direction with cooling.
Defrost by circulation reversal
At temperatures below approx. +5°C, the moisture
in the air freezes to the evaporator (outdoor unit)
and a layer of ice can form, which reduces the
transfer of heat from the air into the refrigerant and
the airflow. This layer of ice must be removed. A
four-way valve serves to reverse the refrigerant cir-
cuit, so that the hot gas from the compressor flows
through the original evaporator and the ice that has
formed there can melt. The defrost process is not
initiated after a predetermined time; rather it is car-
ried out as required in order to save energy.
Cooling mode
Because of circuit reversal, cooling is also pos-
sible. In cooling mode, the components of the
refrigeration circuit are used to produce cold water
with which heat can be extracted from a building.
This can be accomplished with dynamic cooling or
passive cooling.
With dynamic cooling the refrigeration capacity is
actively transferred into the ambient air. This is
undertaken by means of water-based fan convec-
tors. In doing so, it is desirable that the inlet tem-
peratures are under the dew point, in order to
transfer a higher refrigerating capacity and to
dehumidify the indoor air.
Passive cooling is based on heat being absorbed
by cooled surfaces of the floor, walls or ceiling. In
doing so, water-carrying pipes make the structural
sections into thermally effective heat exchangers.
In order to achieve this, the refrigerant temperature
has to lie above the dew point, in order to avoid the
formation of condensation. Dew-point monitoring is
required for this purpose.
We recommend dynamic cooling with fan convec-
tors, in order to achieve increased cooling capacity
and in order to dehumidify the air on muggy
summer days. You can find appropriate KWD,
KWK and WLT-S series units on our website
www.remko.de The advantage here is that dew
point monitoring is not required.
The comfort zone in the illustration below shows
which values for temperature and humidity are
considered comfortable for people. This range
should ideally be met when heating or air-condi-
tioning buildings.
10 12 14 16 18 20 22 24 26 28 30
uncomfortably
humid
comfortable
still comfortable
uncomfortably
dry
Relative humidity in %
Room air temperature in °C
Fig. 25: Comfort zone
REMKO WKF Duo
26