Indoor Lighting Customization Based on Effective Reflectance Coefficients: A Methodology to Optimize Visual Performance and Decrease Consumption in Educative Workplaces

Abstract

The importance of accurate lighting has been proven to be essential for good performance in all kinds of buildings, where most of the professional activities are carried out. National regulations and international standards dealing with indoor lighting establish the technical requirements of lighting installations to ensure the performance of their users. These requirements deal with illuminance on the working plane, uniformity, glare, color temperature of light and some other parameters. However, regulations and technical documents on indoor lighting are mainly referred to standard conditions that are sometimes far away from the reality. Hence, some installations can fulfill the technical requirements, whilst being uncomfortable for task development, impairing user’s performance and are oversized in terms of energy consumption. This work departs from a field study in highlighting the regulatory limitations in the matter of reflectance, to propose a quasi-Lambertian approach to real conditions in indoor workplaces with a special aim in educative environments. It consists of the introduction of “effective reflectance” coefficients for some key visual tasks and furniture carried out by users in certain typical positions and working planes. Based on this coefficient, it is proposed to implement a simple measurement and luminary programming methodology adapted to each particular workplace, especially in educational centers. The final target is to improve visual performance and save energy.