OpenBPS: A New Building Performance Simulation Tool

A new generation building energy performance simula-tion program, OpenBPS™, is currently under develop-ment. It overcomes some of the drawbacks typical of many of the popular building energy simulation programs around the world. This Building Performance Simulation Tool is primarily a set of libraries dedicated to building energy analysis and performance simulation, which can be included in any user-oriented interface or commercial software that aims to perform such analysis. The basic goal of the project is to provide a robust, validated, and high-performing calculation engine that can be shared, and grow with the contribution of a community of developers and users. To maximize its possible deployment and to fa-cilitate its development and extension by a growing com-munity, it has been built as an open source cross-platform (Windows, Mac, and Linux) software library. For this rea-son, OpenBPS™ will be distributed under a Copyleft Soft-ware License (EUPL) and is coded with a cross-platform object oriented programming language, C#, which is an open source language for .NET Framework based on ECMA standards. The main features of this tool are the ob-ject-oriented modelling of physical phenomena and build-ing and HVAC system components, the native code paral-lelization to take advantage of multi-thread/multi-core processors today available, the multi-scale calculation time step (each object can work using its own time step, scaling down or up with respect to the chosen simulation time step), etc. Not only the technical systems are de-scribed and simulated modularly, being their components objects, but also the building fabric is natively modular. Any building envelope component is an object that inter-acts with other objects, which represent the world around it (air node included). This allows the use of different mod-elling approaches for different wall components during the same simulation (linear, non-linear, with phase-change, ventilated, etc.). The input and output data struc-tures are tailored to facilitate third party integration with high efficiency, using today’s technologies. Other planned capabilities include multi-zone airflow simulation and dy-namic models for HVAC system components.