Climate models for the assessment of office buildings energy performance

In the last few years many advanced computer packages, characterised by a considerable integration between thermal and visual aspects, were developed to support designers and to study building energy performance, innovative materials and daylight control strategies and systems. These packages, as a function of their complexity and final use, require different types of outdoor data, ranging from monthly (MTD) or seasonal typical days (STD) to more complex typical meteorological years (TMY). Both the deterministic and the stochastic components of outdoor data are present in TMYs, while MTDs and STDs take into account only the deterministic component. The use of MTDs or STDs produces a sensible reduction of the calculation time, above all appreciable in the first phase of the building design process, although it introduces an element of uncertainty in simulation results due to the absence of the stochastic component of outdoor data. This uncertainty is not easily predictable, as reported by many authors. The aim of the present work is to investigate the influence of the stochastic component of meteorological data in evaluating office building energy performance in Mediterranean climate. The study is performed by an advanced numerical computer package, Integrated ENergy Use Simulation (IENUS), which can process different types of climatic data. Different typologies, systems and space managements are investigated.