2011年の節電対策がオフィス照明環境に与えた影響: 東日本大震災に伴うオフィスの節電照明環境の実態　その1

摘要

オフィスにける人工照明の一次エネルギー消費量は，建物全体の総消費量の約16～19％を占めることが報告されている。人工照明の点灯による発熱は冷房負荷にも係るため，年間を通じて冷房負荷の大きいオフィスでは，照明消費電力の削減が極めて重要である。しかし，照明消費電力の削減は充分に達成されてこなかった照明消費電力は人工照明の点灯時間や設定照度に準じて増大するため，人工照明を消灯あるいは出力を抑えることができれば，消費電力は削減される。%The purpose of this study is to reconsider the optimal lighting conditions in office buildings with respect to both the occupants visual comfort and reduced energy use. This paper reports on how the lighting in office buildings in Japan changed after the events that followed the Great East Japan Earthquake in March 2011. For the first step, a survey of facility managers in office buildings was conducted nationwide. The survey focused on specific measures taken to reduce power consumption. Additionally, the occupants of each office building filled out a questionnaire about the lighting conditions in their working areas. The results showed that for about half or more buildings, saving measures for lighting and air-conditioning during the summer months were taken. With regards to lighting, the number of illuminated lamps was reduced (partial lighting) and ceiling luminaires were turned off automatically at a preset time in order to avoid forgetting to turn them off when unnecessary, such as lunch-time or at the end of working hours. It could be supposed that the desktop illuminance of the most of the office buildings shifted from 750-1000 lx to 300-500 lx due to electricity-saving measures.