Thermal comfort and productivity in offices under mandatory electricity savings after the Great East Japan earthquake

Little is known of workers' comfort and productivity under special conditions, particularly after large disasters. The Great East Japan Earthquake in 2011 caused enormous damage, leading to a 15% peak-power reduction to address power shortages. We investigated occupants' comfort and productivity in five office buildings in Tokyo during the summer season under mandatory electricity savings implemented after the earthquake. We changed the temperature, illumination and ventilation rate settings to investigate their effects on thermal comfort, productivity and energy levels. Occupants were more receptive towards decreased illumination than increased temperature. Awareness of power savings was increased, with more than 90% of people accepting the poor indoor environment in the light of recent events. Set-point temperature and clothing recommendations made by the Super Cool Biz campaign were followed in most offices. However, self-estimated productivity was 6.6% lower than the previous summer. Thus, electricity-saving strategies that do not affect productivity are required.