There are 2 ways to run EnergyPlus simulations in DesignBuilder:

1. The default method directly within DesignBuilder, or,
2. Using the Simulation Manager.

The DesignBuilder Support Desk recommends that you use the Simulation Manager to run and control your simulations because:

• It allows you to run multiple simulations in parallel on your local machine, on a local network machine or on the cloud using the JESS online system
• You can work on your model or close the main DesignBuilder application down while the simulations run.
• You get access to 64-bit versions of EnergyPlus which can run larger models and execute much faster for large models compared with the 32-bit DLL versions used when running EnergyPlus directly in DesignBuilder without the Simulation Manager.
• The Simulation Manager runs simulations in a separate process to the main DesignBuilder application leaving more memory free for your modelling work.
• The Simulation Manager provides a convenient way to store, access and compare simulation results, either via the ResultsViewer or by loading results into the main DesignBuilder application. Storing results outside the DesignBuilder model can help to reduce the memory load on the main DesignBuilder application especially for large models or when large quantities of data are generated.

To use the Simulation Manager simply check the checkbox on the Simulation Manager tab of the Simulation Calculation Options Dialog. No extra hardware or software needs to be installed unless you wish to run simulations on a different machine. One common application of the Simulation Manager is to quickly and easily load multiple result sets into a single ResultsViewer session. The screenshot below shows an example of some comparative results that can be generated with very little effort.

The steps involved are:

1. Open the Simulation manager dialog.
2. Select the completed simulations whose results you would like to compare. Hold the <Ctrl> key and mouse click to add further simulations.
3. Once all the simulations have been selected press the "View results in DesignBuilder ResultsViewer" toolbar icon.
4. In ResultsViewer select the data you would like to view in the left-hand panel and click on the "Add selected variables to new graph" toolbar icon.

For full details on how to use the Simulation Manager to run, control and review your EnergyPlus simulations see the Program help.