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EMS doesn't work correctly in the boundary

asked 2018-07-19 02:56:12 -0500

taher.ahel gravatar image

updated 2018-07-19 10:04:32 -0500

I've modeled a zone and tried to control some HVAC by EMS...but it doesn't report correct answer... to examine what I did, I've removed every thing but my zone. Then write following Simple code, But I observe same thing in variable report:

        ===========  CLASS: SCHEDULE:CONSTANT ===========
    Schedule:Constant,Test,Discrete,0;

       ===========  CLASS: ENERGYMANAGEMENTSYSTEM ===========
    EnergyManagementSystem:Sensor,
    OutdoorTemp,             !- Name
    Environment,             !- Output:Variable or Output:Meter Index Key Name
    Site Outdoor Air Drybulb Temperature;  !- Output:Variable or Output:Meter Name

    EnergyManagementSystem:Actuator,
    Test_Loop,               !- Name
    TEST,                    !- Actuated Component Unique Name
    Schedule:Constant,       !- Actuated Component Type
    Schedule Value;          !- Actuated Component Control Type

    EnergyManagementSystem:ProgramCallingManager,

        Test Program,            !- Name
        InsideHVACSystemIterationLoop,  !- EnergyPlus Model Calling Point
        FanControl;              !- Program Name 1

    EnergyManagementSystem:Program,
        FanControl,              !- Name
        IF (OutdoorTemp < 16.0), !- Program Line 1
        SET Test_Loop = 5.0,     !- Program Line 2
        ELSE,                    !- A4
        SET Test_Loop = Null,    !- A5
        ENDIF;                   !- A6

       ===========  CLASS: OUTPUT:VARIABLE ===========
    Output:Variable,Test,Schedule Value,Hourly;

I observed following report that demonstrate weird thing in the boundary temperature (In 16 degree it reports 2.5 and 1.67 instead of 0): (I've changed Calling Point but the answer is same)

 Date/Time          Temperature   TEST:Schedule Value
 05/15  04:00:00    18.14          0
 05/15  05:00:00    16.05          2.5
 05/15  06:00:00    14.05          5
 05/15  07:00:00    13.8           5
 05/15  08:00:00    16.51          1.67
 05/15  09:00:00    20.46          0

Best Regards

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answered 2018-07-19 04:24:47 -0500

updated 2018-07-19 04:25:13 -0500

Try reporting the EMS variable with Timestep frequency instead of hourly. Probably the values are calculated correctly, but they are averaged over one hour for reporting. e.g.: at 05/15 05:00:00 half of the values are 0 and the other half are 5 during that hour, hence the 2.5.

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Thank you...that's true...

taher.ahel gravatar imagetaher.ahel ( 2018-07-19 04:33:03 -0500 )edit

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Asked: 2018-07-19 02:56:12 -0500

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Last updated: Jul 19 '18