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Siemens
Heating controllers RVP201 and RVP211
CE1P2464en
Building Technologies
3 Technical design
2017-07-21
cates how quickly the room temperature would change if the outside temperature
was abruptly changed. The building time constant has been entered as a fixed value
(21 hours). This represents the average building construction, which is the type of
building structure where the controller is normally used.
The composite outside temperature (T
AM
). It is composed of the two outside tem-
peratures described above, the proportions being as follows:
actual outside temperature (T
A
) = 75 %
attenuated outside temperature (T
AD
) = 25 %
Using this weighting, the composite outside temperature is less attenuated than the
attenuated outside temperature T
AD
.
In the case of short-time variations of the outside temperature, the composite outside
temperature (T
AM
) prevents the control from responding too quickly.
With weather-compensated control, the RVP201/211 only uses the composite outside
temperature.
T
A
(B9)
24
62
B
01
T
A
k
t
T
AD
T
AM
Generation of composite and attenuated outside temperature
T
A
Actual outside temperature
T
AD
Attenuated outside temperature
T
AM
Composite outside temperature
k
t
Building time constant
0
5
10
15
20
25
T
AD
T
AM
t
2
52
2D
17
T
A
T
A
Development of actual, composite and attenuated outside temperature
T
A
Actual outside temperature
T
AD
Attenuated outside temperature
T
AM
Composite outside temperature
t
Time
The control considers the room temperature as follows:
With room temperature-compensated flow temperature control, the deviation of the
actual room temperature from the room temperature setpoint is the only compensat-
ing variable
With weather-compensated control with room temperature influence, the deviation is
an additional compensating variable
The gain factor for the influence of the room temperature can be adjusted. This factor
indicates to what extent a room temperature deviation will change the room tempera-
ture setpoint, thereby acting indirectly (via the heating curve slope) on the flow tem-
perature control:
Room temperature
