.Buildings.Controls.OBC.ASHRAE.G36.AHUs.SingleZone.VAV.SetPoints.Supply

Information

Block that outputs the set points for the supply air temperature for cooling, heating and economizer control, and the fan speed for a single zone VAV system. The implementation is according to the Section 5.18.4 of ASHRAE Guideline 36, May 2020.

Fan speed setpoint

The speed setpoint is calculated in Buildings.Controls.OBC.ASHRAE.G36.AHUs.SingleZone.VAV.SetPoints.SupplyFan. The supply fan shall run whenever the unit is in any mode other than unoccupied mode. Also, a ramp function should be applied to prevent changes in fan speed of more than 10% per minute.

Supply temperature setpoints

The output TSupCooSet is to be used to control the cooling coil, and the output TSupHeaEcoSet is to be used to control the heating coil and the economizer dampers. When it is in deadband state, the output TSupCooSet and TSupHeaEcoSet shall be average of the zone heating setpoint THeaSet and the zone cooling setpoint TCooSet but shall be no lower than TSupDea_min, 21 °C (70 °F), and no higher than TSupDea_max, 24 °C (75 °F). The temperature setpoints are calculated in Buildings.Controls.OBC.ASHRAE.G36.AHUs.SingleZone.VAV.SetPoints.SupplyTemperature.

Note that the inputs uHea and uCoo must be computed based on the same temperature sensors and control loops.

Revisions

• June 30, 2025, by Jianjun Hu:
  Improved setpoints calculation to avoid discontinuity. This is for issue 4282.
• August 1, 2020, by Jianjun Hu:
  First implementation.