Heizen mit Naturwaerme 02-2011_GB.indd - Viessmann

Heat pumps
Cooling with heat pumps
The primary function of a heat pump is to provide pleasant and convenient heat, and
reliable DHW heating. However, they can also be used to cool a building.
Imagine a hot summer's day. Would you
switch your heating on? Probably not, unless
you have a Viessmann heat pump. After all,
heating systems don't generally have much to
do in summer – apart from heating DHW. It is
different for heat pumps, as some Viessmann
heat pumps also offer a cooling function as an
additional benefit.
Active or passive cooling
When cooling with a heat pump, you can
choose between two different methods:
Passive cooling:
This is where the brine medium or the
groundwater absorbs the energy from the
heating circuit via a heat exchanger and
transfers it outside. This function is also
called natural cooling, as it uses the natural
ambient temperature. Apart from the
control unit and circulation pump, the heat
pump remains switched off.
Active cooling:
For this, the function of the heat pump is
simply reversed. This method of cooling
can be described as "reverse operation".
This means that the refrigerant circuit is
reversed internally or reversal is achieved
by an external changeover of the primary
and secondary circuits. As with a fridge,
cooling is then actively generated by the
heat pump.
Cooling naturally: Natural cooling
While the ground or groundwater is used
in winter to provide energy for heating, in
summer it can be used for natural cooling.
With the natural cooling function, the control
unit only starts the primary pump and heating
circuit pump. This means the relatively hot
water from the underfloor heating system can
transfer its heat in the heat exchanger to the
brine in the primary circuit. This extracts heat
from all rooms that are connected. This makes
natural cooling a particularly energy-efficient
and affordable way to cool buildings.
NC-Box
Optional equipment for
Viessmann heat pumps to
provide passive cooling
Page 50
AC-Box
Optional equipment for
Viessmann heat pumps to
provide active cooling
Page 51
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