Development of a new tool for the co-simulation using decomposition of building and HVAC systems in sub systems

Towards the achievement of Nearly-Zero Energy Buildings (nZEB), the call for high performance Building Systems (BS) is undeniable. In order to provide, control and reduce the energy used by the BS, complex and sophisticated technologies are more and more introduced. This complex scenario requires computer simulation to evaluate the building performance at design time. To reach this goal, a Building Performance Simulation Tool (BPST) should carefully consider the accuracy of each component’s input data and the sensitivity of the simulation results to these uncertainties. In order to face this need and to reduce the time required to gather and input these data into a BPST, some manufactures have already started to develop and distribute over the internet their own libraries of “ready-to-use” components. Such approach is moving in the direction of “autonomous” pieces of computer code, which are able to return the components performance, being any component solved according to its own characteristic internal time scale. This leads to the need of solving a system characterized by multiple time and space scales. The influence of these multiple scales on the accuracy of BPSTs’ results is an on-going challenge. To fulfil all those requirements, a tool for the co-simulation of multiple objects (representing walls, air volume and HVAC systems parts) is under implementation and its prototype is here presented. The advantages of this “decomposed description” of the BS, in term of code’s maintainability, error control and code readability are also exposed. This prototype aims to be developed by a distributed community, under an open source licence, and to be freely distributed over the internet.