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Siemens
Basic Documentation RVP360
CE1P2546en
Building Technologies
9 Function block: Space heating
2017-07-24
9.4.9 Optimized switching on
During nonoccupancy times, the controller maintains the setpoint for REDUCED
heating. Toward the end of the nonoccupancy time, optimization switches the con-
trol to boost heating; this means that the set boost is added to the room tempera-
ture setpoint. Optimization calculates the switchover point such that, when occu-
pancy starts, the room temperature will have reached the setpoint for NORMAL
heating.
When the room temperature is simulated by the room model – that is, without room
sensor – the forward shift is calculated as follows:
t [ min ] = ( T
Rw
-
T
RM
)
*
k
t
*
3
where:
t
Forward shift
T
Rw
Setpoint for NORMAL room temperature
T
RM
Room model temperature
k
t
Building time constant in hours
Optimized switching on with the room model is effected only if, previously, quick
setback took place.
Optimized switching on can be deactivated by entering 0 hours for the maximum
heating up time.
9.4.10 Boost heating
For boost heating, a room temperature setpoint boost can be set.
After switching over to the NORMAL temperature, the higher room temperature
setpoint applies, resulting in an appropriately higher flow temperature setpoint.
D.h.w. heating during boost heating does not affect the latter.
t
2
52
2D
0
8
T
R
T
Rw
T
Rx
T
Rw
T
Rw
T
Rw
t
Time
T
R
Room temperature
T
Rw
Setpoint for NORMAL room temperature
T
Rw
Setpoint for REDUCED room temperature
T
Rx
Actual value of room temperature
T
Rw
Room temperature setpoint
T
Rw
Boost of room temperature setpoint (with boost heating)
Duration of boost:
When using a room sensor, the boost is maintained until the room temperature
has reached the setpoint for NORMAL heating. Then, this setpoint applies again
Without room sensor, the room model calculates how long boost heating will be
maintained. The duration is calculated according to the following formula:
