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Siemens Building Technologies
Basic Documentation RVA47.320
CE1P2379E
HVAC Products
Description of the heating engineer settings
15.07.2002
4.11
Composite outside temperature
•
Compensating variable for the flow temperature control
The composite outside temperature is a mixture of the actual outside temperature and
the attenuated outside temperature calculated by the controller.
This operating line automatically displays the actual value [°C] of the composite outside
temperature. No direct setting can be made.
Display
Unit
-50...50 °C
The mixture of actual and attenuated outside temperature is dependent on the type of
building construction (setting 105) and is generated as follows:
Selected type of construction
Composite outside temperature
Heavy (setting 105 = 0)
Tagem = ½ TAakt + ½ TAged
Light (setting 105 = 1)
Tagem = ¾ TAakt + ¼ TAged
The composite outside temperature as a compensating variable acts on flow
temperature control, that is thus matched to the prevailing weather conditions.
It also acts on the 24-hour heating limit to shut down the heating.
13
14
15
16
17
23
71
D12
18:00
06:00
06:00
18:00
18:00
t
TA
TAakt
TAged
°C
TAgem1
TAgem0
TAakt
Actual outside temperature
TAged
Attenuated outside temperature
TAgem1
Composite outside temperature for light building structures
TAgem0
Composite outside temperature for heavy building structures
Benefit
Description
Setting
Process
Effect
Example