Influence of the light distribution of luminaires and the room surfaces’ reflectance on the illumination levels, uniformity and glare in indoor lighting systems

The increasing use of LED luminaires provides a lot of opportunities for indoor lighting. On one side the use of LED luminaires can lead to significant reduction in the electricity consumption for lighting, on the other side it can be so tuned that it allows human centric lighting. The advantages of LEDs as light sources are indisputable, but they also have some drawbacks, that should be considered. A lot of attention is currently payed to optimization of the light distribution curves of luminaires for indoor lighting. It is very important, but not the only characteristic that should be considered. The real reflective properties of the indoor surfaces also influence to great extend the quality and quantity of indoor lighting. The current paper aims to make a detailed review of the existing LED luminaires and their efficiency for indoor lighting, based on their light distribution curve and the reflective properties of the surfaces in the room space. Except for the qualitative, also the quantitative properties of the lighting systems are considered in terms of uniformity of the illuminance and glare. One of the designed solutions is also practically realized and experimentally tested. A comparison between designed and real values of illuminance, uniformity and glare is made.