A study on the effect of facility renewal in small and mid-sized office buildings oriented to net-zero energy buildings-Measuring the effect of setting a cool space in summer-

Recently, in Japan, ZEB has received attention since the need for energy self-sufficiency in buildings has been strongly recognized from the viewpoint of energy security. However, in small and mid-sized buildings with huge stocks, efforts are still small due to factors such as uncertainty in design methods and costs. In this paper, we verify the effect of cool spaces installed in entrances as one of the installation facilities applicable to small and mid-sized stock buildings. A summer experiment on cool space was conducted. From the questionnaire, we confirmed the improvement of thermal sensation and thermal comfort after entering an office room using a cool space. Moreover, using the operation data of air conditioning, the influence on the power consumption by installing a cool space was analysed. As a result, there was no reduction in the energy consumption of the entire building. However, in the office with a high cool-space utilization rate, we confirmed that the air-conditioning power consumption of the whole day has been reduced by 7.3%. These results show that cool space has the effect of improving comfort, and if more workers use it, an energy saving effect for the whole building can be expected.