Underfloor Heating - Viessmann Vitotronic 200 Operating Instructions Manual

Terminology
(cont.)
The enthalpy heat exchanger is able to obtain not only
heat from the extract air, but also a large proportion of
the moisture it contains. This enables the humidity
heat exchanger to create a more pleasant indoor ambi-
ence, particularly during colder times of year, as it pre-
vents the indoor air becoming too dry.
Power-OFF
At times of high demand for electricity, your power sup-
ply utility can block the power supply to your appliance
[Germany]. During this power-OFF period, the mes-
sage "Power-OFF" is shown on the display.
The appliance restarts automatically with the selected
operating program as soon as the power supply utility
enables the power supply again.

Underfloor heating

Underfloor heating systems are slow, low temperature
heating systems and only respond very slowly to short
term temperature changes.
Reduced noise operation
Air/water heat pumps have an integrated fan. The
speed of this fan can be reduced with this time pro-
gram. This reduces the noise caused by the fan, e.g.
at night.
Heating mode/cooling mode
Standard heating mode/cooling mode
For periods when you are at home during the day, you
heat or cool your rooms to the standard room tempera-
ture. Set the periods (time phases) using the time pro-
gram for central heating/cooling.
Reduced heating mode
For periods when you will be absent or during the
night, you heat your rooms to the reduced room tem-
perature. Set the periods using the time program for
central heating/cooling. With underfloor heating sys-
tems, reduced heating mode only yields limited energy
savings (see "Underfloor heating system").
Note
In reduced heating mode, cooling is disabled.
During power-OFF, central heating is provided by the
heating water buffer cylinder. If no heating water buffer
cylinder is installed or its temperature is too low, the
rooms are heated using the available auxiliary heaters,
e.g. oil boiler, electric booster heater.
DHW can only be heated during the power-OFF period
using the auxiliary heaters.
Therefore, heating to the reduced room temperature at
night and enabling "Economy mode" during short
absences do not result in significant energy savings.
Note
The reduced fan speed results in a reduced available
heating output. With air/water heat pumps with output
control, this can be compensated by increasing the
compressor output if required. This will slightly reduce
the seasonal performance factor.
Room temperature-dependent heating/cooling
mode
With room temperature-dependent operation, a room
will be heated or cooled until the selected room tem-
perature has been reached. For this, a separate tem-
perature sensor must be installed in the room.
The heating output/cooling capacity is regulated inde-
pendently of the outside temperature.
Weather-compensated heating/cooling mode
In weather-compensated mode, the flow temperature
is controlled according to the outside temperature. This
means that only the necessary amount of heating or
cooling is provided to heat or cool the rooms to the
room temperature you have selected.
The outside temperature is recorded and transferred to
the heat pump control unit by a sensor fitted outside
the building.
Appendix
87