The Analysis of Daylight Factor and Illumination in Iranian Traditional Architecture, Case Studies: Qajar Era Houses, Qazvin, Iran

As buildings are the biggest consumers of energy, reducing the total energy consumption in this area may have a significant role in preserving non-renewable resources. Appropriate use of daylight may decrease the need for electric lighting which may lead to reduced energy consumption and costs in lighting. Moreover, in the Iranian traditional architecture, there have been various passive strategies to take advantage of the renewable resources to provide thermal and visual comfort for users. Using daylight is one of these methods and strategies. The present study aims at analyzing the lighting condition of these buildings. Therefore, four buildings in Qazvin city, which belong to Qajar period (1785-7925 A.D.), were selected as the case studies. Then, the elected buildings were simulated as three-dimensional models. Finally, the analysis of daylight factor and illuminance was conducted using Ecotect Analysis, Energy Plus and VELUX Daylight Visualizer Software. After the analysis of data obtained from the respective simulations and their comparison with the extant standards of lighting, it was found that the average daylight factor at all under-scrutiny rooms was acceptable; in addition, 76 percent of rooms required no artificial light during the daytime. The reason for appropriate lighting in these spaces is positioning alongside the sunlit side of the building as well as use of big windows. In addition, the analysis of illuminance shows that the distribution of light in interior spaces is even. Moreover, although much amount of light enters the space, the use of light color prevents contrast and daze while enhances visual comfort.