Supply air temperature and fan speed control with room/ return air temperature reset

For this function, it is absolute necessary to have a temperature sensor connected to the input RoomRetAirTemp of the macro. The supply air temperature setpoint and fan speed is shifted by the room temperature deviation. The room temperature setpoint can be reset by the FilteredOATemp because of the summer compensation and/ or the ContrPtAdj value. The application uses one room temperature PI-controller to sequence the supply air temperature setpoint and the fan speed.

The P-band and the I-time of the room temperature controller are respectively defined by parameters RMT-01and RMT-02. The P-band and I-time of the supply air temperature controller are respectively defined by parameters SAT-03 and SAT-04. The supply air temperature setpoint is always limited by the low and high temperature values as defined by parameter SAT-01 and SAT-02.



Description

Default value

RMT-01: room temperature control P-band

2 K

RMT-02: room temperature control I-time

0 sec

RMT-03: span for SAT-setpoint shift

60 %

SAT-01: supply air temperature low setpoint

14 °C

SAT-02: supply air temperature high setpoint

35 °C

SAT-03: supply air temp. control P-band

200 K

SAT-04: supply air temp. control I-time

50 sec


Winter compensation of the supply air temperature setpoint

To eliminate increased building transmission losses and from the comfort point of view (during the winter period), a higher supply air temperature is desired. With decreasing outside temperatures, the supply air temperature setpoint is reset as defined by parameters WCS-01 and WCS-02.

The winter compensation raise is defined by parameter WCS-03, shifting the supply air temperature setpoint between the respective minimum and maximum limit setpoints SAT-01 and SAT-02 upwards.


Note: If parameter WCS-03 is set to “0”, there will be no winter compensation.




Description

Default value

WCS-01: start point OAT winter comp. SAT

-10 °C

WCS-02: end  point OAT winter comp. SAT

10 °C

WCS-03: supply air temperature setpoint raise

4 K


Sequential control of the output signals, based on supply air temperature

In the control strategy module the sequencing of all output control signals can be defined. The respective output signals are destined for heating, energy recovery and cooling.

With the parameters SAT-05 to SAT-12 the start- and the end-point of each output signal can be adjusted, based on supply air temperature control, as shown in the next example.


Note: The end-point parameters must always have a higher value then the start- point parameters. If both start- and end-point parameters are set to “0”, then that particular sequence function will be inactive.



Description

Default value

SAT-05: sequence start point heating valve

0 %

SAT-06: sequence end point heating valve

50 %

SAT-09: sequence start point energy recovery

50 %

SAT-10: sequence end point energy recovery

75 %

SAT-11: sequence start point cooling valve

75 %

SAT-12: sequence end point cooling valve

100 %