Energy simulation of buildings with a modular object-oriented tool

The aim of this work is to develop a modular object-oriented tool “NEST” (Numerical Edifice Simulation Tool) for the energy simulation of buildings, which can be coupled with a parallel CFD software. For this purpose, a building is modelled as a collection of basic elements (walls, rooms, outdoor, openings, etc.). Different models (1D, 2D, simplified energy balances, CFD & HT, etc) are implemented for different elements which are capable of solving themselves for given boundary conditions. The elements can be linked to each other to form a specific building configuration. Thus new configurations can be quickly formed by adding or removing the required elements. Such an approach gives flexibility of choosing a model for each element and to have different levels of modelling for different elements in the system. Moreover, elements developed can be used for applications not restricted to buildings only. The object-oriented methodology, element descriptions, BESTEST cases for code validation, and transient thermal simulations of two different cases are presented in this paper.