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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
25
22
D
18
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