Field Measurement
In this research the indoor air temperature was measured with HOBO data loggers in the cold period of February 2011 for one week, which included a survey day. The measurements assessed thermal conditions of the classrooms before the exam period and winter holiday( Fig. 2).
Temperature ° C
24 19 14 9 4-1-6
02 / 02 / 2011 00:02 02 / 02 / 2011 04:02 02 / 02 / 2011 08:02 02 / 02 / 2011 12:02 02 / 02 / 2011 16:02 02 / 02 / 2011 20:02 02 / 03 / 2011 00:02 02 / 03 / 2011 04:02 02 / 03 / 2011 08:02 02 / 03 / 2011 12:02 02 / 03 / 2011 16:02 02 / 03 / 2011 20:02 02 / 04 / 2011 00:02 02 / 04 / 2011 04:02 02 / 04 / 2011 08:02 02 / 04 / 2011 12:02 02 / 04 / 2011 16:02 02 / 04 / 2011 20:02 02 / 05 / 2011 00:02 02 / 05 / 2011 04:02 02 / 05 / 2011 08:02 02 / 05 / 2011 12:02 02 / 05 / 2011 16:02 02 / 05 / 2011 20:02 02 / 06 / 2011 00:02 02 / 06 / 2011 04:02 02 / 06 / 2011 08:02 02 / 06 / 2011 12:02 02 / 06 / 2011 16:02 02 / 06 / 2011 20:02 02 / 07 / 2011 00:02 02 / 07 / 2011 04:02 02 / 07 / 2011 08:02 02 / 07 / 2011 12:02 02 / 07 / 2011 16:02 02 / 07 / 2011 20:02 02 / 08 / 2011 00:02 02 / 08 / 2011 04:02 02 / 08 / 2011 08:02 02 / 08 / 2011 12:02 02 / 08 / 2011 16:02 02 / 08 / 2011 20:02 02 / 09 / 2011 00:02 02 / 09 / 2011 04:02 02 / 09 / 2011 08:02 02 / 09 / 2011 12:02 02 / 09 / 2011 16:02 02 / 09 / 2011 20:02 02 / 10 / 2011 00:02
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Time |
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S |
N |
Outdoor |
Minimum Comfort |
Figure 2: Measured indoor air temperature in Classroom N and S for one week in February 2011
Based on the field measurement results, the mean indoor air temperature was less than 21 ° C in Classroom S and around 23 ° C in Classroom N during the February field study experiment, which slightly fell within Heidari’ s( 2010) defined comfort zone( Eq. 1). Heidari’ s defined comfort zone was based on a decade of thermal comfort field studies on Iranian people in the residential and office buildings in fifteen cities and in four different climatic regions of Iran( Heidari 2010). It showed that the occupants were able to tolerate a wide range of temperatures, covering more than 14K in the hot season and 7K in the cool season. He cited that, in the hot and dry climate of Iran, people can make themselves comfortable between 16.5 ° C and 22 ° C in the cold season and between 28 ° C and 34 ° C in hot seasons, by adjusting their clothes, activity and air velocity( Heidari 2010). To identify the indoor comfort temperature( T) in the case study school building and to predict the initial comfort temperature ranges, the following equation( eq. 1) was used, based on Heidari’ s( 2010) predictions. T is the monthly mean outdoor temperature.
T = 17.80 + 0.30 T( Heidari, 2010)( 1)
Moreover, in this study, the mean radiant temperature was assumed to be equal to the indoor air temperature in the measured classrooms. According to Fanger( 1973) and Santamouris( 2008), when the occupants have sedentary activity less than 1.5 met and the air velocity is below 0.1 m / s, or the air is still in the indoor environment, the mean radiant temperature can be assumed to be equal to the indoor air temperature( Santamouris 2008; Fanger 1973) which was the condition in this study.
Questionnaire Survey
The questionnaire-based survey was conducted in classrooms S and N, while the indoor air temperature was measured with HOBO data loggers. The questionnaire survey was carried out on the 9th Feb 2011. Around 45 questionnaires were distributed to the students in two classrooms and the students were asked to fill in the questionnaires regarding their thermal sensations and based on the 7-point ASHRAE scale( ASHRAE 2004) and 3-point Mc-Intyre scale( McIntyre and Gonzalez 1976). The results of the questionnaire survey indicated that more the majority of the students’ responses fell into the central three categories of the ASHRAE scale, slightly cool(-1), neutral( 0), and
752 ZEMCH 2015 | International Conference | Bari- Lecce, Italy