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Siemens Building Technologies Basic Documentation RVD230 CE1P2383en
HVAC Products 12 Function block Space heating 27.05.2004
12.9.3 Process
HP Heating program t
3
Quick setback
T
R
Room temperature TRw Room temperature setpoint
t Time
T
Rw
Setpoint of normal room temperature
t
1
Forward shift for early shutdown
T
Rw
Setpoint of reduced room temperature
t
2
Forward shift for the start of heating up TRx Actual value of the room temperature
12.9.4 Room model temperature
To ascertain the room temperature generated by the room model, a distinction must be
made between 2 cases:
• The RVD230 is not in the quick setback mode:
The room temperature generated by the room model is identical to the current room
temperature setpoint
• The RVD230 is in setback mode:
The room temperature generated by the room model is determined according to the
following formula:
t
Room model temperature T
RM
= (T
Rw
- T
AM
) × e
3
×
k
t
+ T
AM
2522D18
t
1
T
Rw
T
RM
T
Rw
T
Rw
Progression of the room temperature generated by the room model
e 2.71828 (Basic Documentation of natural logarithms) T
R
Room temperature
k
t
Building time constant T
RM
Room model temperature
t Time in hours
T
Rw
Setpoint of normal room temperature
t
1
Quick setback
T
Rw
Setpoint of reduced room temperature
T
AM
Composite outside temperature