Heating Terminology - Viessmann VITOVALOR PT2 Operating Instructions Manual

Heating terminology

Reduced heating mode
For periods when you will be absent or during the
night, heat your rooms to the reduced room tempera-
ture. Set the periods using the time program for central
heating. With underfloor heating systems, reduced
heating mode only yields limited energy savings (see
"Underfloor heating system").
Room temperature-dependent heating mode
In room temperature-dependent mode, the flow tem-
perature is controlled according to the room tempera-
ture. More heat is made available at a lower room tem-
perature than at a higher one.
The room temperature is captured and transmitted to
the control unit by a sensor. The sensor is fitted in the
room.
The flow temperature is regulated independently of the
outside temperature.
Weather-compensated heating mode
In weather-compensated mode, the flow temperature
is controlled according to the outside temperature.
More heat is made available at a lower outside temper-
ature than at a higher one.
90
80
70
60
50
40
30
Fig. 14
Example:
For outside temperature
Underfloor heating system, slope 0.2 to 0.8
A
Low temperature heating system, slope 0.8 to 1.6
B
Micro CHP system with a flow temperature in
C
excess of 75 °C, slope 1.6 to 2.0
Factory-set slope = 1.4 and level = 0.
(cont.)
10 0 -10
-14
Outside temperature in °C
14 °C:
−
The outside temperature is captured and transmitted to
the control unit by a sensor. The sensor is fitted to the
exterior of the building.
Heating curve
Heating curves illustrate the relationship between the
outside temperature, the set room temperature and the
flow temperature. The lower the outside temperature,
the higher the flow temperature.
In order to guarantee sufficient heat and minimum fuel
consumption at any outside temperature, the condi-
tions of your building and your micro CHP system must
be taken into consideration. The heating curve is set
by your heating contractor for this purpose. Changing
the set room temperature shifts the heating curves
along the "Set room temperature" axis.
The heating curves shown apply with the following set-
tings:
Heating curve level = 0
■
■ Standard room temperature (set value) = 20 °C
Slope
1.4
C
1.2
1.0
B
0.8
0.6
0.4
A
0.2
-20 -30
Appendix
49