fan coil unit control with setpoint deadband

edit

I think what @Yingying Tai wants to model is as follows.

I also want to model the thermostat control because it is specified in ANSI/ASHRAE/IES Standard 90.1 Performance Rating Method Reference Manual.

However, as @Aaron Boranian answered, ZoneControl:Thermostat:StagedDualSetpoint has limited applicability. It is not for all types of HVAC system. Then, another option is to use Temperature Difference Between Cutout and Setpoint in ZoneControl:Thermostat, but the problem is that Temperature Difference Between Cutout and Setpoint does not have a deadband above a cooling setpoint. The thermostat control would be as follows. That's not what @Yingying Tai and I expect.

I'm thinking of one makeshift. Temperature Difference Between Cutout and Setpoint is set to 1deltaºC, and ThermostatSetpoint:SingleCooling is changed from 24ºC to 24.5ºC. Then, the thermostat control would be as follows. It's pretty much what @Yingying Tai and I expect, but there is another problem. For unmet hours, Tolerance for Time Cooling Setpoint Not Met is based on the thermostat setpoint, so the setting below would report so many unmet hours.

Tolerance for Time Cooling Setpoint Not Met needs to be set to 1deltaºC as follows.

Nov 2023

I revised the second chart. The range of "Tolerance for Time Cooling Setpoint Not Met" was incorrect.

@Keigo @Yingying Tai

It looks like in the EnergyPlus source code, this warning is triggered by the following code:

    } // loop over NumStageControlledZones
    if ((inputProcessor->getNumObjectsFound(state, "AirLoopHVAC:UnitaryHeatPump:AirToAir:MultiSpeed") == 0) &&
        (inputProcessor->getNumObjectsFound(state, "AirLoopHVAC:UnitarySystem") == 0) &&
        (inputProcessor->getNumObjectsFound(state, "SetpointManager:SingleZone:OneStageCooling") == 0) &&
        (inputProcessor->getNumObjectsFound(state, "SetpointManager:SingleZone:OneStageHeating") == 0)) {
        ShowWarningError(state, format("{} is applicable to only selected HVAC objects which are missing from input.", cCurrentModuleObject));
        ShowContinueError(state, "Model should include one or more of the following objects:  ");
        ShowContinueError(state, "AirLoopHVAC:UnitaryHeatPump:AirToAir:MultiSpeed, AirLoopHVAC:UnitarySystem, ");
        ShowContinueError(
            state, "SetpointManager:SingleZone:OneStageCooling, and/or SetpointManager:SingleZone:OneStageHeating. The simulation continues...");
    }

Essentially, if the model is missing all four object types mentioned in the warning, then the ZoneControl:Thermostat:StagedDualSetpoint object type will not work. However, if you have even one of those mentioned object types, then it should work. In other words, a model should correctly apply the staged dual setpoint thermostat to an air system with:

• An AirLoopHVAC:UnitaryHeatPump:AirToAir:MultiSpeed object, regardless of setpoint manager
• An AirLoopHVAC:UnitarySystem object, regardless of setpoint manager
• Any AirLoopHVAC object, as long as SetpointManager:SingleZone:OneStageCooling or SetpointManager:SingleZone:OneStageHeating objects are used