Workers' awareness and indoor environmental quality in electricity-saving offices

Owing to the enormous damage caused by the Great East Japan Earthquake of 2011, a 15% reduction in peak power consumption was required to address the gap between demand and supply capabilities in the summer of 2011. Electricity-saving measures are promoted in offices today for both environmental and safety reasons, and indoor office environments have changed greatly. This paper aims to reveal to what extent workers' awareness of electricity-saving has changed since the earthquake disaster had an impact on energy consumption and productivity. The authors have conducted continuous fieldwork and questionnaire surveys in seven electricity-saving office buildings in the summers of 2011-2013. Additionally, our laboratory's past research data were collected together and analyzed. The results show that excessive indoor air temperatures, such as 28°C, were avoided, and the desk level illuminance greatly decreased, from 750lux to around 400lux, after the earthquake. People learned to implement electricity saving in a proper way that does not spoil workers' comfort, and workers' acceptability zone for the indoor environment was extended by the experience of electricity-saving. Moreover, when we compared individual differences in the way environmental information is perceived, it was shown that differences in the workers' awareness of electricity-saving had a more profound effect on their satisfaction with the indoor environmental quality than those in their gender or age. Mechanical power-saving is definitely important; however, building devices that induce the occupants' energy-saving actions are vital. Our results will be considerably useful to other countries, whether or not they experience a natural disaster.