Table of Contents
Advertisement
42/126
Siemens Building Technologies
HVAC Products
Impact of the room temperature setpoint change on the flow temperature setpoint
∆
w
Change of room temperature setpoint
R
s
Heating curve slope
∆
w
Change of flow temperature setpoint
VT
The flow temperature setpoint change
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 for each heating circuit is to be set
separately on operating line 5.
T
V
110
100
90
80
70
60
50
40
30
20
15
10
20
5
Heating curve
s
Slope
T
the composite outside temperature
AM
T
Flow temperature
V
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 cal-
culated as follows:
∆
10 ×
T
V
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 nonlinear radiation characteristics of the differ-
ent types of radiators.
Basic documentation RVD240
12 Function block Space heating
S
∆
w
is calculated according to the following
VT
s
27,5
40
35 32,5 30
=
0
-10
-5
-15
25
22,5
20
17,5
15
12,5
10
7,5
5
2,5
-20
-25
-30
-35
T
AM
CE1P2384en
27.05.2004
Advertisement
Table of Contents
