Investigation Report of Lighting Characteristic Deterioration because of Long-term Use(<Special Issue>Drafting a Proposal for the Appropriate Timing for Replacing a Luminaire)

Abstract

Although some surveys have been conducted on the issue of lamp replacement or luminaire cleaning, not enough information about deterioration of illuminating properties, caused by a long-term usage, is available. Therefore, we conducted a preliminary survey on the deteriorations of the luminaires that have been actually used (for 12 to 41 years in offices). We measured the light output ratio, the vertical illuminance, and the distribution curve of luminous intensity, at the time these sample luminaires were removed, and we understood the degree of deterioration (20% lower output ratio), and confirmed that cleaning luminaires (light reflectors), which the Illuminating Engineering Institute of Japan has been proposing, was proven to be effective.