A NEW APPROACH FOR THE ESTIMATION OF DEPRECIATION FACTOR AND ENERGY LOSS IN LIGHTING SYSTEM

摘要

In lighting systems, luminaires, lamps and wall surfaces become dirty in the long run. Besides, the luminous flux in the lighting elements also decreases depending on usage. As a result, the brightness level in interior space decreases gradually. The amount of decrease in the lightness level is determined by the depreciation factor (df). For the detection of depreciation factor, measurements should be taken at several different points over the lighting system. By using these measurements, the average brightness levels can be calculated according to the standards which are prepared by the Chartered Institution of Building Services Engineers (CIBSE). The depreciation factor is calculated by using the average brightness values in the next step. This is a process that requires time and effort. In the present study, an ANN model was created as an alternative to all these long and exhaustive measurements and this ANN was trained for estimation of depreciation factor. The correlation coefficient (r) of the trained ANN was calculated as 0.99. The fact that the actual and obtained estimated values were close to each other. After 24 months from the first obtained data, the existing lighting system has been improved and so 20 of the electricity energy which does not produce light has been recovered. Thus, energy waste and light loss were prevented. Moreover, the ergonomic comfort conditions of the lighting environments were kept at the desired level.