Summer electrical energy consumption for different cooling systems

Among the consequences of the urban development of the last decade of Bucharest, the capital of Romania, one notices a strong increase in energy consumption, in particular on electrical energy used for air-conditioning systems. This city is characterized by a continental climate, where the summer temperature often exceeds 30degC, so the airconditioning represents an absolute need; moreover, the urban planning of the city introduced accents created by tall buildings (15 - 20 floors) with entirely glazed facades, which are great energy consumers during summer period. The application of the European directive for Building Performance (no. 91/2002) determined the creation of a method for energy efficiency calculation of the buildings, which will be certified according to their consumption. We present here the results of an estimate of the energy consumptions obtained by the extension of the national regulation methodology, applied to various systems of air-conditioning. On the basis of the energy balance of a building and its cooling systems, we present a hourly evaluation method of the consumption of electrical energy for air-conditioning, for the hottest month of the year, July. This method was applied for an office building with an important glazed area, equipped with an air-conditioning ldquoall-airrdquo or ldquoair-waterrdquo system.