Yixing Chen's profile - activity

When you use the Output:Variable, set the time step to 'timestep', e.g., Output:Variable,*,Zone Mean Air Temperature,tim

@W. Chiang, Yes. You can import DDY file for system sizing without the EPW file. You need to modify the SimulationControl object as follow:

SimulationControl,

Yes, !- Do Zone Sizing Calculation

Yes, !- Do System Sizing Calculation

Yes, !- Do Plant Sizing Calculation

No, !- Run Simulation for Sizing Periods

No; !- Run Simulation for Weather File Run Periods

Nice. I forgot the .new.

Thank you.

Do anyone use the OpenStudio::Model::ShadingSurfaceGroup(model) in Ruby API?

I got the error as follows: :in create_os_object': undefined methodShadingSurfaceGroup' for OpenStudio:Module (NoMethodError)

I tested it on both OS Version: 1.14.0 and 1.12.0.

Any suggestions?

Also, do we have to associated the ShadingSurface with ShadingSurfaceGroup always?

The OS:ShadingSurface was in the osm. But don't transfer to any shading object in E+.

Currently, OpenStudio can't read all the IDF objects. For example, it can read the geometry from IDF file and it can't read most of the HVAC systems. So far as I know, all the energy modeling tools with good user interface can only handle part of the IDF objects.

So the messages you received is informative. They are not "Errors". You can follow the information to export the untranslated objects.

I checked two BuildingSurface:Detailed for the same wall. They have same coordinates. So the two BuildingSurface:Detailed objects show in the same zone, while the nearby zone shows "missing wall".

     ! Block 2, Hol, Partition - 3.913 m2 (Block 2, Yasam10), Surface Area: 3.9132
     BuildingSurface:Detailed,                      !- Surface
            Block2:Hol_Partition_41_0_0,                !- Surface name
            Wall, Balatcik_BolmeDuvar_UnitelerArasi,    !- Class and Construction Name
            Block2:Hol,                                 !- Zone Name
            Surface, Block2:Yasam10_Partition_6_0_10049,   !- Outside Face Environment
            NoSun,                                      !- Sun Exposure
            NoWind,                                     !- Wind Exposure
            0,                                          !- View Factor to Ground
            4,                                          !- Number vertices
             2.0222122255,-4.9760001718, 19.09753871,   !- Vertex 1
             2.0213437487,-3.3280264607, 19.09753871,   !- Vertex 2
             2.0213437487,-3.3280264607, 21.47207749,   !- Vertex 3
             2.0222122255,-4.9760001718, 21.47207749;   !- Vertex 4

     ! Block 2, Hol, Partition - 3.913 m2 (Block 2, Yasam10), Surface Area: 3.9132 <Other side>
     BuildingSurface:Detailed,                      !- Surface reverse definition
            Block2:Yasam10_Partition_6_0_10049,         !- Surface name
            Wall, Balatcik_BolmeDuvar_UnitelerArasi_Rev,!- Class and Construction Name
            Block2:Yasam10,                             !- Zone Name
            Surface, Block2:Hol_Partition_41_0_0,       !- Outside Face Environment
            NoSun,                                      !- Sun Exposure
            NoWind,                                     !- Wind Exposure
            0,                                          !- View Factor to Ground
            4,                                          !- Number vertices
             2.0213437487,-3.3280264607, 19.09753871,   !- Vertex 1
             2.0222122255,-4.9760001718, 19.09753871,   !- Vertex 2
             2.0222122255,-4.9760001718, 21.47207749,   !- Vertex 3
             2.0213437487,-3.3280264607, 21.47207749;   !- Vertex 4

The DDY file is used for zone/system/plant sizing (design day simulation), while the EPW file (typically including hourly data for a year) is used for annual (a period) energy simulation.

The DDY file is in IDF format. You can copy and paste the objects in DDY file to IDF file.

The sizing simulation run the simulation of the design periods and provide the Component Sizing Summary Report based on the calculated maximum capacity of the design periods. The results depend on DB temperature, wind speed, solar condition, and etc. You can't determine the "max ambient condition" before you run the sizing simulation.

The report name is "ZoneCoolingSummaryMonthly". This report created one table for each zone. There is a column named: "ZONE TOTAL INTERNAL LATENT GAIN RATE {Maximum}[W]".

You can add the report name to the "Output:Table:SummaryReports" object.

Output:Table:SummaryReports,
    ZoneCoolingSummaryMonthly;              !- Report 1 Name

Can you share the IDF file and specify the version of OpenStudio?

The following errors happen when I try to update the plugins from OpenStudio 1.4.0 to OpenStudio 1.8.0, OpenStudio 1.8.4, or OpenStudio 1.9.0. I tried both 32 and 64 bit version of OpenStudio. Any ideas?

I use SketchUp 8.0:

The OpenStudio 1.4.0 works good with this SketchUp version.

Errors from OpenStudio SketchUp plug-in 1.4.0.4cd6ad08de:

File at DOASDXCOIL_wADPBFMethodDCV5outdoortest2EMS1.idf is not valid to draft strictness 
 The collection is INVALID at strictness level 'Draft', because of the errors:
Field      level data error of type DataType          .
Error is in an object of type 'Sizing:System', named '', in field 20.
Additional information about the error type: field-level data is of an incorrect type.
Field      level data error of type DataType          .
Error is in an object of type 'AirConditioner:VariableRefrigerantFlow', named '', in field 66.
Additional information about the error type: field-level data is of an incorrect type.
Field      level data error of type DataType          .
Error is in an object of type 'Curve:Cubic', named 'VRFCoolCapFTBoundary', in field 10.
Additional information about the error type: field-level data is of an incorrect type.
File at C:/Users/yixing/Downloads/DOASDXCOIL_wADPBFMethodDCV5outdoortest2EMS1.idf is not valid to draft strictness 
 The collection is INVALID at strictness level 'Draft', because of the errors:
Field      level data error of type DataType          .
Error is in an object of type 'Sizing:System', named '', in field 20.
Additional information about the error type: field-level data is of an incorrect type.
Field      level data error of type DataType          .
Error is in an object of type 'AirConditioner:VariableRefrigerantFlow', named '', in field 66.
Additional information about the error type: field-level data is of an incorrect type.
Field      level data error of type DataType          .
Error is in an object of type 'Curve:Cubic', named 'VRFCoolCapFTBoundary', in field 10.
Additional information about the error type: field-level data is of an incorrect type.
File at C:/Users/yixing/Downloads/DOASDXCOIL_wADPBFMethodDCV5outdoortest2EMS1.idf is not valid to draft strictness 
 The collection is INVALID at strictness level 'Draft', because of the errors:
Field      level data error of type DataType          .
Error is in an object of type 'Sizing:System', named '', in field 20.
Additional information about the error type: field-level data is of an incorrect type.
Field      level data error of type DataType          .
Error is in an object of type 'AirConditioner:VariableRefrigerantFlow', named '', in field 66.
Additional information about the error type: field-level data is of an incorrect type.
Field      level data error of type DataType          .
Error is in an object of type 'Curve:Cubic', named 'VRFCoolCapFTBoundary', in field 10.
Additional information about the error type: field-level data is of an incorrect type.

The EPW file is hourly data. Is there a way to use 1-minuge interval weather data in EnergyPlus?

I have the measured airflow rate with 1-minute interval (variable speed fan) for the DOAS system. Can EnergyPlus specify the airflow of the airloop or fan to match the measured airflow rate?

It is not possible to override the room air temperatures (or other status parameters, such as room air humidity ratio, room CO2 concentrations) at a particular node using an EMS program.

The room air temperatures are included in the heat balance equations, which are ordinary differential equations. In the solver, you need not only the temperature values, but also the derivatives. Most of the system nodes are somehow connected to the room air temperatures. So simply changing the status parameters is not a option in EMS.

Are there any web-based APIs that can accept IDF file as input and return the 3D geometry view of IDF files? So I can put the results into my website.
It will be great if the view can have the similar behavior as SketchUp, such as Zoom in/out, rotate, move.
I mean web-based APIs, so the return should be in HTML format.

@ngkhanh So if you use "SizingPeriod:WeatherFileDays", you can do the zone, system, and plant sizing, and simulation runs using the same period of weather data.

@ngkhanh The "run simulation for sizing periods" is similar to "Run Simulation for Weather file run periods". The "Run simulation for sizing periods" use the "SizingPeriod:" objects as the weather data, while the "Run Simulation for Weather file run periods" use RunPeriod:" objects as the weather data. Both results are outputs to the *.csv and other output files.

The "Ideal Zonal System" and "Ideal Loads Sizing Simulations" are the same thing. They only work in zone sizing period. The results from the zone sizing period will be used to determine the sizes of HVAC systems in system sizing.

The "run simulation for sizing periods" is similar to "Run Simulation for Weather file run periods". The "Run simulation for sizing periods" use the "SizingPeriod:" objects as the weather data, while the "Run Simulation for Weather file run periods" use "RunPeriod:" objects as the weather data. Both results are outputs to the *.csv and other output files.

@TiejunWu You can check the EMS document at page 28-30 for the calling points. Depend on your HVAC system, the value may be changed after the "AfterPredictorAfterHVACManagers" point.

@ngkhanh Search my name in LBNL phonebook, you should be able to find my email address.

You need to use EMS for the control.
Here is an example code for your case. Replace the "VAV_System_Default OA Controller" with the name of your "Controller:OutdoorAir". And change the xxx, yyy, zzz to your control parameter.

EnergyManagementSystem:Actuator,
VAV_System_Default_OA_Flow_Rate,    !- Name
VAV_System_Default OA Controller,    !- Actuated Component Unique Name
Outdoor Air Controller,    !- Actuated Component Type
Air Mass Flow Rate;        !- Actuated Component Control Type

EnergyManagementSystem:Program,
Set_VAV_System_Default_OA_Flow_Rate,    !- Name
IF totalAirFlow < xxx,    !-  xxx is your changing point of the total flow rate in kg/s
Set VAV_System_Default_OA_Flow_Rate = yyy,    !- yyy is your minimum OA flow rate in kg/s
ELSE,
Set VAV_System_Default_OA_Flow_Rate = totalAirFlow * zzz, !- zzz is your proportional ratio
ENDIF;                    !- End of code

EnergyManagementSystem:Sensor,
totalAirFlow,
VAV_System_Default OA Controller,
Air System Mixed Air Mass Flow Rate; 

EnergyManagementSystem:ProgramCallingManager,
Control_VAV_System_Default_OA_Flow_Rate,    !- Name
AfterPredictorAfterHVACManagers,    !- EnergyPlus Model Calling Point
Set_VAV_System_Default_OA_Flow_Rate;    !- Program Name 1