The purpose of this study is to obtain findings for the conservation of the sound environment in after-school childcare facilities. A sound environment survey and environmental adjustment using sound-absorbing materials were conducted in two after-school childcare facility. In the sound environment survey, reverberation time and the sound levels during activities were measured, children’s activities were observed, and interviews were conducted with facility staff. Then, in order to provide spaces where children can spend time calmly, we implemented spatial adjustment with consideration for the sound environment and confirmed its effectiveness through interview surveys.

The ventilation rates for childcare facilities that are already built and in operation comply with the Japanese Building Standards Act (2003), which includes an air exchange standard of 0.3 per hour to prevent sick house syndrome. However, these rates fall below the ventilation levels recommended by COVID-19 precaution protocols, raising concerns about infection risks. This study demonstrates that upgrading a mechanical ventilation system to operate at approximately 20 m³/h per person effectively improved indoor CO₂ levels. Additionally, the upgraded system reduced stagnant air and provided more uniform air distribution. Therefore, ventilation design should prioritize per-person rates over current standards.

ZEHs, which take into account the insulation performance of the external skin and the reduction of solar heat gain during the cooling season, are becoming increasingly popular. In this paper, the relationship between the rated capacity of AC and the applicable floor area in ZEH was investigated based on the heating and cooling load of the LDK of ZEH and the heating and cooling capacity of AC. The average power consumption of ACs in LDKs of ZEHs in actual dwellings was also obtained from HEMS data to estimate the operating conditions.