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Siemens
Heating and D.h.w. Controller RVL481
CE1P2541en
Building Technologies
10 Function block "Space heating"
20.05.2008
10.5.2 Room
influence
The room temperature is included in the control process. For that purpose, a room
sensor is required (sensor or room unit).
The gain factor of the room temperature influence on the flow temperature control can
be adjusted. This indicates to what extent deviations of the actual room temperature
from the setpoint have an impact on the flow temperature control:
0 = room temperature deviations have no impact on the generation of the setpoint
20 = room temperature deviations have a maximum impact on the generation of the
setpoint
The change of the room temperature setpoint
∆
T
Rw
is calculated according to the fol-
lowing formula:
VF
2
∆
T
Rw
= × (T
Rw
- T
Rx
) [K]
T
Rw
T
R
T
Rw
The change of the flow temperature setpoint
∆
T
Vw
resulting from the change of the
room temperature setpoint is calculated as follows:
∆
T
Vw
=
∆
T
Rw
× (1 + s) [K]
s Heating
curve
slope
TRw
Room temperature setpoint
∆
TRw Change of room temperature setpoint
−∆
TRw Decrease of room temperature setpoint
+
∆
TRw Increase of room temperature setpoint
TRx
Actual value of the room temperature
∆
T
R
Room temperature deviation (T
Rw
– T
Rx
)
∆
TVw Change of flow temperature setpoint
VF Gain
factor
10.6 Heating curve
10.6.1 Purpose
With the space heating systems (plant types 1–x, 2–x, and 3–x), flow temperature con-
trol is always weather-compensated. The assignment of the flow temperature setpoint
to the prevailing outside temperature is made via the heating curve.
10.6.2 Basic
setting
The setting of the heating curve is made via the bar or 2 operating lines. The following
settings are required:
•
Flow temperature setpoint at an outside temperature of
−
5 °C
•
Flow temperature setpoint at an outside temperature of +15 °C
The basic setting during commissioning is made according to the planning documenta-
tion or in agreement with local practices.
