IMPACT OF ORIENTATION AND BUILDING ENVELOPE CHARACTERISTICS ON ENERGY CONSUMPTION Case Study of Office Building in City of Nis

Buildings are one of the biggest energy consumers in urban environments, so its efficient use represents a constant challenge. In public objects and households, a large part of the energy is used for heating and cooling. The orientation of the object, as well as the overall heat transfer coefficient (U-value) of transparent and non-transparent parts of the envelope, can have a significant impact on building energy needs. In this paper, analysis of the influence of different orientations, U-values of envelope elements, and size of windows on annual heating and cooling energy for an office building in city of Nis, Serbia, is presented. Model of the building was made in the Google Sketch Up software, while the results of energy performance were obtained using EnergyPlus and jEplus, taking into account the parameters of thermal comfort and climatic data for the area of city of Nis. Obtained results showed that, for varied parameters, the maximum difference in annual heating energy is 15129.4 kWh, i. e per m(2) 27.75 kWh/m(2), while the maximum difference in annual cooling energy is 143561 kWh, i. e per m(2) 26.33 kWh/m(2). Considering that differences in energy consumption are significant, analysis of these parameters in the early stage of design process can affect on increase of building energy efficiency.