ABSTRACT
Areas far away or isolated from the windows, like rooms in centralised air conditioned buildings, can be illuminated with natural light during the daytime by using light pipes. However, depending on the weather condition, sometimes daylight coming from the light-pipe is not sufficient for illumination. During these times, when natural lighting is not adequate or more lighting is needed, artificial lighting is used. However, generally, all the artificial lighting components are operated together without considering the intensity of the illumination. This in turn, causes efficient renewable energy use. Prior to the savings in energy, energy simulation is to be done in the sample building taken, using desired software and considering the weather conditions for determining the effective availability of daylight. Control systems can be used for illumination systems. Savings in energy consumption for lighting or daylight harvesting will be achieved through daylight integration by controlling the system with methods such as switching on–off by user, manual or automatic dimmers with timers or demand control, etc. Actually, the main concern is the maximum optimisation in usage of daylight keeping in mind cost-effectiveness, i.e. maximum utility of solar energy at minimum cost possible.
