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Building modeling using measured data

asked 2015-04-30 13:17:02 -0500

Wilson gravatar image

updated 2015-04-30 14:30:50 -0500

Hi, I’m new in building energy modeling and I would like to ask for your help. I need to create a building model from a year information data that was measured in a building. That data (Temperature, CO2, moisture) was measured in several points inside the building and in one point outside the building. I also have all building energy consumption data and HVAC energy consumption data(Kwh). The building that I need to model is a shopping center and I have other important data information like occupants number. All this data was measured in a 15 minutes step. I need to create a building model in order to simulate the buildind behaviour for the next/hours days to adjust HVAC setpoints, always considering important info like outside weather. I’m reading several tutorials and I understand that is possible to design a building using SketchUP and then use OpenStudio to make the simulations needed. Can you tell me if is possible to use OpenStudio to create a building model from this data that I have without using SketchUP and building construction details?

Thank you

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A couple questions:

  • Are you able to get the Building Information Model from the designer?
  • Are you trying to implement a model predictive control strategy?
MatthewSteen gravatar image MatthewSteen  ( 2015-04-30 14:20:25 -0500 )edit

This work is for my university final project. I can't get more building information so the data I refered is the only information I have. I need to implement a building predictive optimization using EnergyPlus but I don't know yet all EnergyPlus potencial. The main goal is to predict the building thermal behaviour in order to reduce HVAC power consuption by adjusting HVAC setpoints.

Thank you

Wilson gravatar image Wilson  ( 2015-04-30 19:38:53 -0500 )edit

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answered 2015-05-02 14:19:04 -0500

updated 2015-05-02 14:20:11 -0500

If I understand your question correctly you would like to simulate an existing shopping mall from which you have a year of measured data but would like to avoid or simplify building the model. This may be quite difficult because the data you have is the result of the geometry, construction, loads, and systems specific to that building. For reference, the traditional way one would conduct a calibrated simulation in OpenStudio is the following.

  1. Obtain the design documentation from the architect to build model geometry [SketchUp]
  2. Create spaces and assign them to thermal zones
  3. Obtain actual meteorological year (AMY) file for the site and assign to model [OpenStudio]
  4. Enter utility bill information (tutorial)
  5. Assign schedules, constructions, and loads to model objects
  6. Build the central HVAC system(s) and add zone HVAC equipment
  7. Run the model, view results, and adjust inputs to train the model to the data

In your case I would consider using a DOE Commercial Reference Building as a proxy for the vintage, type, and climate zone of your building. Currently these complete EnergyPlus models cannot be imported directly into OpenStudio. However, the IDFs can be imported into SketchUp and/or OpenStudio which will preserve everything but the HVAC systems I believe. If you can wait until June OpenStudio Prototype Buildings may be available with the next release.

After updating the model inputs for the data you have instead of training your model to monthly energy use I would use monthly energy use intensity calculated from your utility data. From here you could (1) use the built in OS utility calibration feature shown in the tutorial link above or (2) use the OpenStudio Analysis Spreadsheet to calibrate your model using this example.

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Another option might be ORNL Autotune

MatthewSteen gravatar image MatthewSteen  ( 2015-05-02 17:05:01 -0500 )edit

Thank you for your help and time MatthewSteen.

Wilson gravatar image Wilson  ( 2015-05-03 14:16:27 -0500 )edit
3

answered 2015-05-01 09:25:32 -0500

Waseem gravatar image

You can also try training an artificial neural network (black box modelling). Depending on the type of data you have, you may be able to predict building energy consumption, thermal comfort etc. In this way you don't need model of the building, HVAC system etc. and you will be using historical data to train your neural network.

I hope this will help.

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Using ANN is a way to solve my problem but two important requirements of this work is to use measured data and EnergyPlus. It's possible EnergyPlus to run using measured data and SketchUp building model simultaneously?

Thank you for your answer

Wilson gravatar image Wilson  ( 2015-05-01 11:15:44 -0500 )edit

I am not aware of any method that you can use to model your building without setting up your building (i.e. the physical model). Just to clarify, when you say using measured data and EnergyPlus together, what you mean by this?

Waseem gravatar image Waseem  ( 2015-05-01 11:24:49 -0500 )edit

As EnergyPlus is oriented to physical models I was wondering If I can use 1 year building measured data that I have(Temperature, CO2, moisture,occupancy) and the SketchUp building model in the same simulation.

Wilson gravatar image Wilson  ( 2015-05-01 12:24:44 -0500 )edit

@Wilson: I would suggest you build your building energy model in EnergyPlus (OpenStuido) and then use that one year data to calibrate your model. By this way, your EnergyPlus model will behave like the actual model. This will enhance your controller performance that you will develop afterwords, as predictive control methods heavily rely on the quality of the model. IF there is mismatch between the model and original building then you will have real issues. I hope I have answered your question.

Waseem gravatar image Waseem  ( 2015-05-01 13:03:15 -0500 )edit

Thank you for you help Waseem.

Wilson gravatar image Wilson  ( 2015-05-01 14:20:25 -0500 )edit
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answered 2015-05-15 10:27:15 -0500

I'm making a user guide for the OpenStudio Analysis Spreadsheet. Its taking longer than I would like, but here is a pre-release: https://github.com/NREL/OpenStudio-analysis-spreadsheet/tree/develop/documentation

Note this in the develop branch and will be updated as changes come in. Feedback on it is welcome.

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answered 2015-04-30 14:07:16 -0500

You will need to build the geometry of your building in SketchUp if you are trying to build a calibrated energy model. This is necessary to ensure that you have the correct area and envelope loads to the actual building that you are trying to calibrate to.

Does that answer your question?

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So using only the data I mentioned is not possible to make the corresponding building model? If I want to predict HVAC consuption using EnergyPlus is the measured data I mentioned irrelevant and the only way to do that is to create the building geometry in SketchUp in order to make the needed simulations using OpenStudio? Thank you

Wilson gravatar image Wilson  ( 2015-04-30 19:52:09 -0500 )edit
2

answered 2015-05-01 10:54:33 -0500

Chandan Sharma gravatar image

If the intention is just changing the setpoints, look at LoadProfile:Plant object (PlantLoadProfile EnergyPlus example file) to see if it can be of any help. It lets you specify the building load directly if you know it without creating building. Then you only need to add plant loop.

Otherwise, yes, building geometry with appropriate constructions/materials, windows data should be created using SketchUp/OpenStudio. Internal loads such as occupancy/lights/plug loads and infiltration values should be specified in the model and HVAC should be setup. Run the input file using weather file of building location (can insert measured outside data in weather file). Calibrate the model using measured energy consumption and/or inside temperature/RH data etc. Once there is enough confidence in the calibrated model, apply measures such as changing setpoints. This will be a fairly time consuming process which requires expertise. If you are not familiar with EnergyPlus, you have to start with tutorials available.

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Thank you for your answer Chandan. I'm starting now my EnergyPlus Knowledge. I'm not familiarize yet with your suggestion but I will keep it in mind.

Wilson gravatar image Wilson  ( 2015-05-01 12:31:37 -0500 )edit

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Asked: 2015-04-30 13:17:02 -0500

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Last updated: May 15 '15