The EnergyPlus engine used for the loadmodeling.tool simulations is both powerful and highly customizable. The customization provides control over the resolution of results, run times, and calculation methodologies. Currently, a curated array of settings are open to users to adjust parameters such as time step. The remaining settings are set to standard defaults to reduce the complexity of running each simulation In the future more settings will be opened along with clear guidance on when and why certain settings may be adjusted.

Settings Page Guide

Settings Page Guide. Open in new tab to enlarge

Running the model

In order to run the model and produce results, simply hit the Run Model button on this page. A dialog will appear that provides an estimate of the simulation run time and shows progress. Once complete the dialog will notify you and guide you directly to the results!

Past Runs - Simulation History

Previous runs can be found in the Simulation History on the rightmost panel. If a model needs adjustments mid-run, a cancel button is also available here.

Current adjustable settings

Heating Sizing Factor - the Heating Sizing Factor is applied globally to all peak heating results. The resulting load value can be viewed in the load_summary.xlsx export as Room Heating Safety.

Cooling Sizing Factor - the Cooling Sizing Factor is applied globally to all peak heating results. The resulting load value can be viewed in the load_summary.xlsx export as Room Cooling Safety.

Project Orientation - the degrees from North Axis can be adjusted prior the simulation running. When drawing the building the Y axis will be north by default. This can be adjusted by entering the Project Orientation into the Default Settings. For convenience, this rotation can also be down directly here. More details and an example can be found in this help article.

Run for Room Sizing - this toggle controls the secondary EnergyPlus simulation that produced the Room results. If these are not required for your project, the simulation can be turned off. The second simulation will use the same settings as the primary.

Run for Energy - This toggle controls the annual (8760 hours) whole-building energy simulation run. When this toggle is on, users will be able to get energy-related reports and access the time-series page where hourly results can be analyzed.

Timestep Per Hour - defines the calculations per hour. The default is 6, so 6 calculations per hour, or a calculation every 10 minutes. More calculations per hour provide more resolution to fast-changing conditions; however, it also increases simulation run time.

Current standard default settings

  • Minimum warmup days - 2

  • Maximum number of warmup days - 25

  • Temperature convergence tolerance - 0.4

  • Loads convergence tolerance - 0.4

  • Solar distribution - FullExterior

  • Inside surface convection algorithm - CeilingDiffuser

  • Outside surface convection algorithm - DOE-2

  • Heat Balance Algorithm - ConductionTransferFunction

  • Zone air heat balance algorithm - ThirdOrderBackwardDifference

  • Radiance parameters - Coarse

For complete descriptions and explanations of the Simulations Settings of EnergyPlus please refer to section 1.5 of the Input Output Reference.

Video Tutorial

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