Quality and efficiency of office lighting

The use of artificial lighting in the office buildings has significant contribution on total energy consumption of the building. With the increase in the price of energy and public becoming more energy conscious, more attention has been given to the energy efficient lighting. On the other hand, with increased trend to go for efficient lighting systems, the quality of lighting has to be maintained. Efficient lighting and quality lighting are not contradictory to each other and the better understanding of these two terms would be helpful to promote the improvement of the energy efficiency. The present paper first gives an overview of the different factors related to the quality of lighting in office environment. Different studies about the occupant’s preference on light level, light distribution, colour, and other quality aspects have been summarized. The effect of efficiency measures on lighting quality is well discussed. Use of occupancy sensors, application of daylight and dimming according to daylight are some of the promising energy saving techniques. The result of the energy consumption measurement carried out in office rooms with different lighting control systems and their comparison shows that significant improvement in efficiency can be made without compromising on quality.