S Ekinović, J Vivancos
2013 Yalcin Journal of Trends in the Development of Machinery and Associated Technology   unpublished
Energy is a very important factor in our life in many ways and consumption of energy is essential fact for humankind to maintain their lifestyle. Nowadays, large scale buildings as office buildings, shopping centers and schools consume lots of energy and in this manner; they harm both national economies and environment. Energy efficient cooling solutions and natural ventilation is a good alternative in order to decrease energy consumption for summer periods in large scale buildings. In this
more » ... ldings. In this study, energy consumption of a school building's cooling system in Istanbul, Türkiye was examined. Also, natural ventilation effect on energy efficiency of the cooling system was studied.. The building consists of 12 lecture halls, 10 seminar rooms, 20 lecturer rooms, 5 man and 5 woman WCs, 3 disabled WCs, 2 club rooms, 2 shops and 1 big canteen, in 9296.34 m 2 area. It is estimated that natural ventilation is not always the feasible solution to decrease the energy consumption without appropriate control methods. 1. INTRODUCTION Climate change is one of the major problems of the world lately [1]. The most important reason of this change is global warming, which is the result of increasing greenhouse gases emission. Increasing trend of greenhouse gases is an energy consumption connected with fossil fuels. On the other hand, energy is very important in our lifes on all hands [1] and energy consumption is essential for people. The uphill task is decreasing energy consumption with continuing economic growth. Thus, energy efficient solutions and strict rules must be performed. Nowadays, buildings like offices, shopping centers, schools, etc. consume great amount of energy in order to maintain comfort and affect both environment and national economies negatively. Alternative energy methods and energy efficient solutions are essential to prevent this amount of energy consumption. Özbalta, T.G. estimated that buildings have about 30% to 50% energy saving potential with these methods and solutions [2]. The increased efficiencies of heating and hot water systems, air conditioning, ventilation, lightening installations, depend on the technological developments, are the reason of major energy saving potentials in buildings. Increasing energy efficiency in buildings is not only decreased end use energy demand, but also decreased large amount of CO 2 emission, thus it helps to prevent global warming effect on the world. One way of increasing efficiency in buildings is natural ventilation. Making ventilation via natural ways provides economical and environmental benefits, 94.4% end use energy consumption in buildings is spent by HVAC systems within the life cycle period of building [3]. So, natural ventilation (NV) is very popular alternative against HVAC systems, lately. But in some climates air conditioning with natural ventilation is not enough to provide human comfort [4]. In these cases, supplemental mechanical systems have to be used and these type of air conditioning systems are called hybrid systems. Lomas, K.J. et. al. said that "Hybrid buildings can reduce energy consumption whilst offering the potential to combat tough climatic and site conditions and the prospect of meeting stringent internal environmental conditions" [5].