Energy efficiency in office buildings: lighting sector

Abstract

Efficient utilisation of energy is considered to be one of the main tools of controlling the ever increasing demand for energy, especially in developing countries where there is a large potential for improvement. In recent times, the efforts to improve efficiency have been largely concentrated in the electricity sector mainly due to its rapid growth in the developing nations, which is as high as 8% to 10% annually. The broader objective of this study was to develop "building codes" addressing the energy efficiency aspect within commercial buildings considering areas such as thermal comfort, lighting and other building services. This included deriving electricity requirements for different activities such as air-conditioning and lighting, giving due emphasis to different tasks performed within different types buildings. It has considered the fact that lighting and thermal comfort levels required by people in different countries differ depending on the type of environment they are generally exposed to. The paper describes the studies carried out to address the lighting sector of office buildings covering different tasks, with recommendations for optimum lighting levels to perform these tasks in Sri Lanka. These studies included assessing visual performance of people involved in different activities under varying illumination levels in a controlled environment and a comparison of these optimum lighting levels with international standards. It could be seen that the required optimum lighting levels are generally lower in Sri Lanka which is likely to be the case in many developing countries thereby clearly emphasising the need to adopt their own lighting standards in turn helping improved energy efficiency within buildings.