Comparison of Different Methods of Measuring Illuminance in the Indoor of Office and Educational Buildings

Background: The light is one of the electromagnetic waves that can be created from conversion of electrical energy into a visible energy for human eye. The illumination intensity is measured in order to compare with the quality standards of light and for estimation of energy waste and lighting system performance. Therefore, the systematic and scientific measurement principles in data validation are very important. Objectives: The purpose of this study was to measure the actual artificial lighting by various valid procedures. Materials and Methods: The overall, artificial and natural lighting has been measured at different times and in rooms with open and closed blinds mode and based on the various measuring stations. Results: The results show the artificial lighting obtained by difference methods of the overall lighting from natural lighting in closed blinds mode equal to 266 Lux and night lighting 283.5 Lux that they have no significant differences with each other (P = 0.269). As well as the illumination intensity obtained from a standard grid method is 283.5 Lux and illumination intensity based on Luminaires layout model is 274 Lux with no significant difference (P = 0.269) Conclusions: The present study shows that method of difference (subtracting the overall light from natural light) can be a good option to measure the illumination intensity of artificial lighting system in any state (open or closed curtains) and time of the day and a standard method for measuring the lighting per residential, administrative and training units.