Survey on relationship between the ratio of window-opening area and the indoor and outdoor climate mainly for the season of natural ventilation

Abstract

The relation between the ratio of window-opening area and the indoor and outdoor climate was surveyed in the university campus in Kyoto for seven months mainly for the season of natural ventilation. The subject rooms were (1) occupied with from five to ten graduate students, (2) used mainly for desk work, (3) without heavy effect of traffic noise, (4) with approaches to the windows, (5) with air conditioners. The survey was carried out by (1) the observation of window-opening area for the same type of 125 sliding windows of 74 rooms regularly two or three times a day, (2) the measurement of the indoor climate for 7 rooms of the observed rooms every ten minutes, and (3) the record of the occurrence of opening and closing behaviours by sensors fixed to the frames of 19 windows of the 7 rooms every ten minutes. The results were as following. (1) Outdoor temperature was correlated with the ratio of window-opening area highly in the season of natural ventilation, while there was little correlation in heating or cooling season. (2) In heating season the ratio was lower but it sometimes went beyond five percent. (3) The differences of the ratio in a day were less than two percent for more than 80 percent of the days. (4) Daily mean outdoor temperature was correlated with daily mean ratio for cooling season as well as for the season of natural ventilation. (5) Almost all of the indoor temperatures were within a zone of 80% acceptability in Adaptive Model. The range of indoor temperature was wider for the rooms with frequent opening behaviours than for those usually kept closed.