## IDF 301 - Batch running multiple simulations using EP-Launch ### Prepare IDF files Often it is nice to run simulations on a series of models that have one aspect changed slightly from model to model to look at energy sensitivity to the aspect being altered. Below are some examples of what you might vary from one model to the next. building orientation wall R-value percentage of glazing geometry of shading devices changes to occupancy schedule aspect ratio of building number of floors building location solar panel positioning The first step is to create a series of IDF files based on an original file. There may be times that you don't need to create multiple IDF files. For example if you are just simulating a design in multiple cities, or if you are using a tool that will generate the design variations for you. For this demonstration the IDf creation will be manual, and the aspect of the design that will change is the building orientation. The first step is to open your IDF file in OpenStudio and go to the plugins menu in SketchUp. Choose "Plugins/OpenStudio/Simulation Info". Change the Coordinate System to "Relative Coordinates". (Credit: David Goldwasser/NREL) Once the coordinate system has been set, save and close your IDF file. Then create as many copies of the file as you want to run. Rename them to identify what is changing, for example, adding a prefix of "020" to identify a rotation angle of 20 degrees. Below you can see an IDF field where the North rotation angle changed from "0" to "20" degrees. (Credit: David Goldwasser/NREL) Back to Top ### Batch run simulations with EP-Launch Once your files have been created go to the EnergyPlusV5-0-0 folder and open the "EP-Launch.exe". This application can be used to run single simulations or to run multiple simulations. Press the "New Group" button to get started. Note that on the Mac OS Ep-Launch light doesn't support batch or group simulations. (Credit: David Goldwasser/NREL) The next step is to choose the IDF files you want to simulate. Once you define the path you can choose all of the files or manually pick them. (Credit: David Goldwasser/NREL) Next you can pick one or a group of weather files. If you choose a group of weather files then the list of IDF files will be simulated for each weather location. So if you have 10 IDF files and 4 weather files, you will have 40 simulations run. (Credit: David Goldwasser/NREL) After you choose the IDf and weather files, you have an opportunity to add additional simulations, or remove specific ones from the list. (Credit: David Goldwasser/NREL) Next you define where the simulation results will be saved. Choose "User Defined Location". (Credit: David Goldwasser/NREL) You will be prompted for a path to save the EnergyPlus Group file. This saves all of your preferences making it easy to re-run the batch simulation if you make changes to the IDF files. After that choose "Simulate Group" to start the simulations. (Credit: David Goldwasser/NREL) When the simulation run is done you will have a sub folder for each weather location setup for the group. All of the simulation results are inside of the corresponding weather folder. (Credit: David Goldwasser/NREL) Back to Top ### View batch simulation results You can view the simulation results for each simulation like you would for a single simulation. You can look at the html and error files, and can open the IDF in OpenStudio and load the ESO file. There are also some nice tools that work well for viewing results of multiple simulations at once. EP-Compare is made just for this. It is located under the EnergyPlus install under "PostProcess\EP-Compare\EP-Compare.exe". When you first open it choose "Manage Files" and then choose the directory with the simulations you want to compare. (Credit: David Goldwasser/NREL) Once the files are loaded you can view the data in a variety of different ways. Each section of the graph is for one of the simulation runs. In this case North rotation of "0" is at the left, and "160" is at the right (20 degree steps). It was a symmetrical building so the simulation set didn't need to go through the entire 360 degrees of rotation. (Credit: David Goldwasser/NREL) ResultsViewer is another application for viewing simulation results. While it is very nice for viewing details from a single simulation, it can also open multiple SQL files at once. Then if you use the filter tool you can trim down your list of variables and choose one from each simulation file. ResultsViewer will show you a more detailed picture about specific times of year or times or times of day. "ctrl" click each value you want and then right click and choose "line plot". The graph below shows monthly results, which was requested along with hourly values in the IDF files. (Credit: David Goldwasser/NREL) The graph above looks at the entire building, but you can also look at specific zones. The graph below shows the Sensible Cooling Rate for one of the first floor perimeter zones. You can see there is some cross over in the stacking order of the lines depending upon the time of year. This could be a good tool to inform what shading devices might need to look like on different facades depending upon the building orientation. (Credit: David Goldwasser/NREL) Once you have completed your batch simulation and reviewed the results hopefully you have gained information to inform your design process. There could be a number of things you could do next to follow up. You may want to change the building design and then go back and re-run the simulation group again. If you are happy that you have addressed the building orientation for project, then maybe you create a new simulation group to study the percentage of glazing, shading devices, or on envelope constructions. This is a powerful tool that leverages the work you have already done to create the energy model. It also helps to validate assumptions about the efficiency of different design variations. Back to Top

U.S. Department of Energy