Overview

This document provides some best practices for creating OpenBuildings Energy Simulator models.

Method

Care should be taken when drawing your building, as a badly designed model can lead to the following:

• Runtime Errors
• Extended calculation times
• Irregular or unexpected results

A model should be constructed as accurately as possible though with some consideration given to design complexity. Simplicity can be the key to your design allowing for a robust and accurate model.

Utilising the AccuSnap settings below can assist with this.

AVOID:

• Unnecessary Plenum Rooms: in the vast majority of cases it is advised that models are constructed without any plenum rooms. Guidance can be found on this at:
  Floor, Room and Plenum Height - OpenBuildings | AECOsim | Speedikon Wiki - OpenBuildings | AECOsim | Speedikon - Bentley Communities
  
  
• Overly intricate surfaces and room layouts: There are instances where a room layout may contain unnecessary surfaces and recesses. For Design Simulation or PartL, this would generate a number of extra surfaces which will slow down the calculations. 
  
  
• Incorrect adjacencies: Room adjacencies will usually be created automatically, along with whether a surface is exposed or internal. However if a model is inaccurately traced then adjacent surfaces may not be defined correctly, resulting in inaccurate calculations.
  
  
• Rounded surfaces: While the software doesn't intrinsically support spherical surfaces, they can be modeled reasonably accurately by incorporating a series of straight wall sections. You should be aware however that a large number of surfaces would have an adverse effect on the time taken to run simulations. It may also introduce more surfaces than the SBEM calculation engine (PartL) can handle. We recommend using as few surfaces as possible model the curved wall, without drastically affecting the room floor area.