Abstract
Cross-ventilation is one of the most traditional and popular cooling means against the hot humid summer in Japan. Preference of people for it might be attributed in main to the fact that fluctuating air flow caused by natural wind makes people feel refreshing. However there are few reports on the comfort caused by natural air flow. This paper describes the experiments on the effect of cross-ventilation on thermal sensation of people carried out in two dwellings in August 1984 and from June through July in 1985. The experiments are composed of 64 runs in total, employing five male and five female subjects in college age. In a run of the experiment a subject in 0. 3 do clothing was sedentary in 60 or 90 minutes, facing to the windward. Whenever their comfort sensation changed, the subject were requested to vote sensations to air flow. Air flow sensation was voted on 6-category scale and six kinds of feeling of air flow characteristics on 7-category scale. The experimental rooms are in well-ventilated and typical summer indoor conditions as shown in Fig. 3 and Fig. 4. The cumulative frequency distributions of air flow velocity for six levels of air flow sensation are shown in Fig. 8. There is no significant difference in median of velocity of each level between male and female. Fig. 9 compares air flow sensation between whole body and local body. The most sensitive part of the body is shank, which has high correlation with whole body. The reason is that shanks are exposed, facing air flow and peripherial parts of the body comparing with the others. Correlation matrix between air flow sensation and six kinds of feeling of air flow characteristics is given in Table 3. Speed, strength and fluctuation feelings of air flow are highly related with air flow sensation of whole body and each other, with correlation coefficients larger than 0. 75. It is considered that these three feelings, characterizing natural air flow, influence air flow sensation. Therefore relations between these feelings of air flow characteristics and physical parameters of air flow are shown in Fig. 15 to Fig. 18. Speed feeling and fluctuation feeling have high correlation to air velocity but no relation to the standard deviation of air flow turbulence and the turbulence intensity.
