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Siemens Building Technologies
Basic Documentation RVL471
CE1P2524E
HVAC Products
10 Function block "Space heating"
23.10.2002
t
25
22
D
1
9
T
RM
T
R
t
1
T
RM1
T
Rw
T
Rw
T
Rw
T
Rw
where:
k
t
Building time constant in hours
t
Time
t
1
Duration of room temperature setpoint boost with boost heating
T
R
Room temperature
T
Rw
Setpoint of NORMAL room temperature
T
Rw
Setpoint of REDUCED room temperature
T
RM
Room model temperature
T
RM1
Room model temperature at the beginning of boost heating
TRw
Room temperature setpoint
∆
TRw
Boost of room temperature setpoint (with boost heating)
10.5 Room functions
10.5.1
Maximum limitation of the room temperature
For the room temperature, it is possible to have an adjustable maximum limitation. For
that purpose, a room sensor is required (sensor or room unit).
If the room temperature lies 1 °C above the limit value, the room temperature setpoint
will be lowered by 4 °C.
Maximum limitation of the room temperature is independent of the setting used for the
room influence.
If the room temperature lies above the limit value, the display shows
.
The reduction of the flow temperature setpoint
∆
T
Vw
is calculated as follows:
∆
T
Vw
[K] =
∆
T
Rw
*
( 1 + s )
-1
-0,5
0,5
1
1,5
2
2,5
3
T
Rw
T
R
s
Heating curve slope
∆
TRw
Reduction of the room temperature setpoint
∆
T
R
Deviation of the room temperature
∆
TVw
Reduction of the flow temperature setpoint
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