Heating Curve - Siemens RVD230 Basic Documentation

Siemens Building Technologies
HVAC Products
Impact of the room temperature setpoint change on the flow tem-
perature setpoint
∆w
Change of room temperature setpoint
R
s heating curve slope
∆w
Change of flow temperature setpoint
VT
The flow temperature setpoint change ∆w
formula:
∆w = ∆w
× ( s × 0.1 + 1 )
VT R
12.3

Heating curve

With both types of weather-compensated flow temperature control (with / without room
temperature influence), the heating curve ensures the assignment of the flow tempera-
ture setpoint to the outside temperature. Its slope is to be set on operating line 5.
T
V
110
100
90
80
70
60
50
40
30
20
20 15 10 5
Heating curve
s Slope
T the composite outside temperature
AM
TV Flow temperature
The heating curve has a fixed tilting point at an outside temperature of 22 °C and a flow
temperature of 20 °C. It can be set around this tilting point in the range from 2.5 to 40 in
increments of 0.5.
Each heating curve has a substitute line which intersects the tilting point and "its" heat-
ing curve at an outside temperature of 0 °C. Its slope is set on the controller and is
calculated as follows:
10 × ∆TV
s =
∆T
AM
The use of a substitute line is required because the heating curve is slightly deflected.
This is necessary to compensate for the non-linear radiation characteristics of the dif-
ferent types of radiators.
Basic Documentation RVD230
12 Function block Space heating
S
is calculated according to the following
VT
s 40 35 32,5 30 27,5
=
0 -5 -10 -15
25 22,5
20
17,5
15
12,5
10
7,5
5
2,5
-20 -25 -30 -35
T
AM
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CE1P2383en
27.05.2004