Calculating the optimum window-to-wall ratio according to daylight factor and thermal performance in Mediterranean climate

Abstract

Energy is a significant part of socio-economic development of modern societies. Increasing fossil fuel consumption is almost the main source of energy throughout the world. Thus, it is essential to search for more sustainable alternatives or a method to decrease this huge amount of usage. On the other hand, the building industry is known as one of the biggest energy consumers. Among building energy efficiency measures, openings are playing a key role in declining energy consumption, especially in the hot summers of Cyprus. Therefore, this study carries out a field measurement of various opening sizes in the case study in order to make a satisfactory situation both from energy efficiency and visual comfort considerations. Meanwhile, a studio in a faculty of architecture, Famagusta, North Cyprus, has been selected as an experimental examination to show the effectiveness of the method. In order to analyze its energy performance, the calculation simplified method is chosen. Outcomes are intended to illustrate the benefits of the calculation method and to authorize opening size comparisons to display the differences in energy conservation measures inherent in the various compliance methods allowable by the regulations. Finally, the results obviously display that by decreasing the window-to-wall ratio, the heat loss significantly reduces. But, by considering the daylight factor (DF) in the standard defined range and applying 750lux as an essential lighting requirement for the studio, finding the minimum WWR seems more meaningful. Therefore, according to the mentioned criteria in this special case, an optimum amount of WWR can be considered in the range of 10 to 20%, which gives architects some flexibility to apply in their designs.