38/94
Siemens Building Technologies
Basic Documentation RVD110, RVD130
CE1P2381E
HVAC Products
11 Function block Space heating
27.05.2004
•
Any room temperature deviation produces an instant parallel displacement of the set
heating curve The correlation between the amount of deviation and the extent of dis-
placement is defined by the room authority, which is dependent on
−
the deviation of the actual room temperature from the setpoint
−
the set heating curve slope
The purpose of the room temperature influence is to exactly reach the respective set-
point during the control process and to maintain it.
This type of control operates as PI control. The I-part ensures that any deviation of the
room temperature will be compensated with no offset.
Main application of this type of control are plants or buildings in which one of the rooms
is suited as a reference room for the room temperature.
11.5.3 Weather-compensated control with room temperature
influence
Prerequisites for this type of control:
•
Outside sensor connected
•
Room unit connected
•
Room authority set in the range 1...20
Compensating variables for weather-compensated control with room temperature influ-
ence are:
•
The composite outside temperature
•
The deviation of the actual room temperature from the setpoint
The flow temperature setpoint is continuously shifted via the heating curve as a function
of the composite outside temperature. In addition, any deviation of the room tempera-
ture produces an instant parallel displacement of the heating curve.
The correlation between the amount of deviation and the extent of displacement is
defined by the room temperature influence, which is dependent on
•
the set authority
•
the deviation of the actual room temperature from the setpoint
•
the set heating curve slope
The correcting variable for the flow temperature setpoint is generated from these 3
factors.
Main application of this type of control are well insulated buildings or buildings with
significant heat gains, in which
•
several rooms are occupied at the same time
•
one of the rooms is suited as a reference room for the room temperature
11.6 Automatic ECO energy saver
11.6.1 Fundamentals
The automatic ECO energy saver controls the heating system depending on demand.
ECO considers the progression of the room temperature – which is dependent on the
type of building construction – as the outside temperature changes. If the amount of
heat stored in the building is sufficient to maintain the current room temperature set-
point, the heating will be switched off (valve closes, heating circuit pump deactivated).
The action of the automatic ECO energy saver is dependent on the operating mode:
Operating mode
ECO
Automatic mode
Active
Continuous operation
Inactive
Standby
Active
Manual operation
Inactive
