CE1P2522E / 30.03.2000
Basic Documentation RVL470
Siemens Building Technologies
24/68
Function block "Space heating"
Landis & Staefa Division
•
When using no room sensor, the room model calculates how long boost heating will
be maintained. The duration is determined according to the following formula:
T
Rw
– T
RM1
k
t
t
1
[ h ] = 2
*
––––––––––––
*
––––
T
Rw
– T
Rw
20
The duration of the boost is limited to two hours.
t
25
22
D
1
9
T
RM
T
R
t
1
T
RM1
T
Rw
T
Rw
T
Rw
T
Rw
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 the NORMAL room temperature
T
Rw
Setpoint of the REDUCED room temperature
T
RM
Room model temperature
T
RM1
Room model temperature at the start of boost heating
T
Rw
Room temperature setpoint
∆
T
Rw
Boost of room temperature setpoint (with boost heating)
8.5. Room functions
8.5.1. Maximum limitation of the room temperature
For the room temperature, it is possible to have an adjustable maximum limitation, in
which case a room temperature sensor is required (sensor or room unit). If the room
temperature lies 1 °C above the limit value, the room temperature setpoint will be low-
ered by 4 °C.
Maximum limitation of the room temperature is independent of the setting used for the
room temperature 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
∆
T
Rw
Reduction of room temperature setpoint
∆
T
R
Deviation of room temperature from the limit value (actual value / limit value)
∆
T
Vw
Reduction of flow temperature setpoint
