Daylighting in Riyadh and Los Angeles: comparison of cultural factors in potential market penetration

Choosing an effective daylighting mechanism for a home is a function of its environment: both the climate and the culture. Two distinct locations, Los Angeles, California and Riyadh, Saudi Arabia, are used to compare the use of light tubes to improve the amount of daylight penetrating a residential space. During the daytime in Los Angeles (Latitude 34 N), people receive natural light through the windows of their homes. As a consequence of this preference, lighting systems such as daylighting tubes are often unnecessary because the daylighting through the traditional windows exceeds the minimum design level. In contrast, the residential building interiors in Riyadh (Latitude 24 N) do not achieve the minimum illuminance from the daylight from the windows due to issues and concerns with glare and privacy. Because of the discomfort caused by glare and the culturally-founded concerns regarding privacy, the windows in Riyadh are commonly small and people often keep the curtains closed at all times. Daylighting tubes would allow the residential interiors to achieve the minimum illuminance from daylighting, while also addressing the issues of glare and privacy. Although lighting tubes can be used in any climate and country, certain circumstances make the use of lighting tubes more beneficial. To determine this, four elements were studied, tested, and compared. The four factors were glare, privacy, heat gain, and energy. There are multiple computer programs available to test glare. Hdrscope was chosen because it is one of the best glare programs. A survey was used to analyze and compare the differing levels of the privacy needs of both cities. Heat and energy were examined by using the energy modeling program Integrated Environmental Solutions (IES). The objective is to provide an overview of all common daylighting systems and prove that lighting tubes are more efficient in certain cities and cultures. The effectiveness of a daylighting system relies on more than just climate and sun exposure; cultural norms and traditions also play an important role in determining the optimal lighting system, (Alam, n.d.).