Lighting knowledge
The effect of ROL
The future of efficiency. We have defined a new performance indicator for the measurement of lighting efficiency based on our retail lighting expertise.
ROL tells us what proportion of light reaches the target surface, i.e. the light that is directly available to the consumer to see the merchandise, rather than how much light is emitted from the luminaire.
Return of Light is a practical means of assessing the effect and efficiency of a retail lighting scheme. »The ROL philosophy is based on our intensive research and development activities, and it provides a logical measurement tool for the simple and transparent assessment of product lighting,« commented Volker Knauff, Head of the Ansorg Product Design Centre. »We’re moving away from a simple examination of light quantity towards a specific assessment of the interplay of LED, luminaire and reflector, so that we can identify the light that reaches the product display. In this connection the reflector – or its degree of efficiency – is very significant.« ROL tells us what proportion of light reaches the target surface, i.e. the light that is directly available to the consumer to see the merchandise, rather than how much light is emitted from the luminaire. This minor shift in perception has wide-reaching impacts in practice because a luminaire with a good LOR efficiency rating is not necessarily a good lighting solution.
By planning a retail lighting concept that incorporates the ideal luminaires, it is possible to achieve the desired effect without any loss of light. In other words, no unwanted diffuse light is generated at all in the store, which has two advantages. Firstly, no electricity is wasted on stray light and, secondly, there is no need to adapt the light fittings to prevent undirected light. These seemingly small improvements deliver noticeable positive effects, especially in the retail sector where the lights are switched on for lengthy periods of time. The ROL value makes it possible to establish the best choice of luminaire with a precisely defined light output.
In retail lighting the reflector, with its faceted design, is the pivotal element which focuses the light and directs it to the target surface. The reflector cut-out opening is significant in this connection because low reflectors with small cut-out openings capture more light and efficiently direct it onto the target surface whereas flat reflectors with larger cut-out openings emit a greater amount of direct light that is diffused in the room rather than directed onto the merchandise, so it is wasted. Yet flat reflectors always have a better LOR simply because more light is emitted from them, which is misleading and gives a false impression of efficiency.
Every industry, whether automotive, food, fashion, health & beauty, or home store, has its own target group and product-specific features. These are incorporated into our planning just as naturally as your wishes and aims. Please contact us and we will be happy to help you.