HVAC Mode Dependencies
The HVAC Mode settings in the AirflowSetpointControl folder affects a lot of factors in the VAV application. The below tables offers a basic summary.
|
HVAC Mode |
Effective setpoint |
Space temp. control loop |
DAT
|
Airflow setpoint |
Fan control |
Reheater control |
Perimeter control |
|---|---|---|---|---|---|---|---|
|
Auto |
Heating demand active: effective setpoint equals the heating setpoint Cooling demand active: effective setpoint equals the cooling setpoint |
Cooling CL active |
Heating CL active:
Cooling CL active:
|
Occupied and bypass:
Standby (StandbyAirFlowSetpoint) and unoccupied (UnoccAirFlowSetpoint): the same setpoint for heating and cooling |
Parallel fan: working on heating demand Series fan: working if occupied or standby (if allowed) |
According to the heating demand |
According to the heating demand |
|
Heat |
Occupied: OccHeatTempSetpoint Bypass: OccHeatTempSetpoint Standby: StandbyHeatTempSetpoint Unoccupied: UnoccHeatTempSetpoint |
Heating CL active |
Heating CL active |
Occupied and bypass: linear function between the MaxOccHeatAirFlowSetpoint and MinOccHeatAirFlowSetpoint values Standby (StandbyAirFlowSetpoint): setpoint the same as the auto mode Unoccupied (UnoccAirFlowSetpoint) and |
Parallel fan: working on heating demand Series fan: working only on heating demand if occupied or standby (if allowed) |
According to the heating demand |
According to the heating demand |
|
Cool |
Occupied: OccCoolTempSetpoint Bypass: OccCoolTempSetpoint Standby: StandbyCoolTempSetpoint Unoccupied: UnoccCoolTempSetpoint |
Cooling CL active |
Cooling CL active |
Occupied and bypass: linear function between the MaxOccCoolAirFlowSetpoint and MinOccCoolAirFlowSetpoint values Standby (StandbyAirFlowSetpoint): setpoint the same as the auto mode Unoccupied (UnoccAirFlowSetpoint): setpoint the same as the auto mode |
Parallel fan: inactive Series fan: working only on cooling demand if occupied or standby (if allowed) |
Off |
Off |
|
MorningWarmUp |
Occupied: OccHeatTempSetpoint Bypass: OccHeatTempSetpoint Standby: StandbyHeatTempSetpoint Unoccupied: UnoccHeatTempSetpoint |
Heating CL active |
Heating CL active |
MaxOccHeatAirFlowSetpoint |
Parallel fan: if the WarmUpParallelFan variable is set to true, the parallel fan is active in this mode Series fan: ventilator set to the maximum speed |
According to the heating demand (if WarmUpHeater is true) |
According to the heating demand (if WarmUpHeater is true) |
|
PreCool |
Occupied: OccCoolTempSetpoint Bypass: OccCoolTempSetpoint Standby: StandbyCoolTempSetpoint Unoccupied: UnoccCoolTempSetpoint |
Cooling CL active |
Cooling CL active |
MaxOccCoolAirFlowSetpoint |
Parallel fan: inactive Series fan: ventilator set to the maximum speed |
Off |
Off |
|
Night
|
Occupied: OccCoolTempSetpoint Bypass: OccCoolTempSetpoint Standby: StandbyCoolTempSetpoint Unoccupied: UnoccCoolTempSetpoint |
Cooling CL active |
Cooling CL active
|
MaxOccCoolAirFlowSetpoint |
Parallel fan: inactive Series fan: ventilator set to the maximum speed |
Off |
Off |
|
Fire |
Occupied: OccCoolTempSetpoint Bypass: OccCoolTempSetpoint Standby: StandbyCoolTempSetpoint Unoccupied: UnoccCoolTempSetpoint |
Disabled |
Disabled |
MaxOccCoolAirFlowSetpoint |
Disabled |
Off |
Off |
|
Off |
Occupied: OccCoolTempSetpoint Bypass: OccCoolTempSetpoint Standby: StandbyCoolTempSetpoint Unoccupied: UnoccCoolTempSetpoint |
Disabled |
Disabled |
0 |
Off |
Off |
Off |