One‐year Measurement of Indoor Climate and Energy Consumption of Super‐insulated Houses in a Mild Climate Region of Japan

Two super‐insulated houses were constructed near Sendai City in accordance with the Canadian R‐2000 manual (Canadian Home Builders' Assoc., 1987). Shelter performance, thermal environment, air quality and energy consumption of these two houses were investigated for one year. The two super‐insulated houses were very airtight compared with other houses. The one‐year measurement of room temperature and humidity for one super‐insulated house showed that the daily mean temperature for the dining‐living room and the master bedroom was 15°C‐20°C during the winter and 22°C‐28°C during the summer. Absolute humidity for these rooms was less than 5 g/kg (DA) during the winter. The indoor environment of the two super‐insulated houses during the heating season was more thermally comfortable, compared with that of ordinary houses in Japan. During the summer, the indoor temperature in these two houses was stable during the day and did not decrease at night even if the outdoor air temperature dropped. The CO₂ concentration in these two houses was lower than that of other airtight houses due to continuous mechanical ventilation. The space heating energy consumption for one super‐insulated house was less than that of ordinary houses in Tohoku District in which only the living‐dining room was heated.