How does autosizing work in Simergy?

Simergy – autosizing of component parameters

Capacity and flow rate parameters can usually be autosized (indicated by the A/S postfix to the parameter name). Note that most of the default templates and library entries have the properties set to autosize.

If you set one or more properties to autosize you also need to provide design days, which are used for the sizing calculations in EnergyPlus. In addition, sizing objects at the Zone Group Occupancy template, air loops and water loops define more specifics about the sizing calculation. Autosizing related objects:

  • Design days (typically two summer and one winter design day)
    Note: If you select a standard weather source, those three design days are automatically attached to your project.
  • Zone Sizing
  • Air Loop Sizing
  • Plant Loop Sizing
  • Global Sizing

See an example of each below:

                                                               Design days in the location template in the Site workspace

                                                     Design days properties in the Object Properties dialog

                                                                                    Zone sizing dialog in occupancy template

                                                                              Air loop sizing dialog

                                                                          Water loop sizing dialog

                                                      Global Sizing Parameters in the Simulation Parameter template in the Simulation workspace

                                     Sizing parameters in the Object Properties dialog

In the simulation workspace you can automatically set all parameters with autosize capabilities to autosize by clicking the   button.

When you click the  button, you can apply the sizing results to your model. A new window will pop up that shows the full list of properties with calculated values. You can specify a overwrite value and by clicking the “Save values to model” those values are written into the properties.

                                                                                                          Sizing results dialog

Under some circumstances, EnergyPlus fails to properly size components and creates error messages that stop the simulation. Is may be possible to adjust the sizing object values to resolve this issue or by setting these autosize properties to specific values so the sizing and simulation can run through. After the simulation completes you can reapply the sizing values to get better estimates.