National Conference in Mechanical Engineering Research and Postgraduate Studies (2 nd NCMER 2010) 3-4 December 2010, Faculty of Mechanical Engineering, UMP Pekan, Kuantan, Pahang, Malaysia; pp. 755-761 ISBN: 978-967-0120-04-1; Editors: M.M. Rahman, M.Y. Taib, A.R. Ismail, A.R. Yusoff, and M.A.M. Romlay ©Universiti Malaysia Pahang 755 THERMAL COMFORT IN TECHNICAL SCHOOL: PHYSICAL MEASUREMENT APPROACH N.K. Makhtar 1 , A.R. Ismail 2 , N. Jusoh 3 and A.P. Puvanasvaran 4 1 Department of Mechanical and Manufacturing Engineering Faculty of Engineering, Universiti Putra Malaysia 43400 Serdang, Selangor, Malaysia Email: nkamilahm@gmail.com 2 Faculty of Mechanical Engineering, Universiti Malaysia Pahang 22600 Pekan, Pahang, Malaysia 3 Department of Mechanical and Material Engineering Faculty of Engineering and Build Environment, Universiti Kebangsaan Malaysia 43600 UKM Bangi, Selangor, Malaysia 4 Faculty of Manufacturing Engineering Universiti Teknikal Malaysia Melaka (UTeM) Ayer Keroh, 75450 Melaka, Malaysia ABSRACT A field study on the relationship between thermal comfort and students’ performance was carried out in a technical school in Selangor. The buildings were mechanically ventilated by fans. The measured environmental parameters were air temperature (ºC), mean radiant temperature (ºC), relative humidity (%) and air velocity (m/s) of the surrounding classroom area. The environmental factors were measured using Thermal Comfort Equipment, which is capable to measure simultaneously all the environmental factors. All the windows were left open for natural ventilation. Subjective measurements were also conducted using survey questionnaire on the same days when the environmental factors were measured. The Predicted Mean Vote (PMV) was calculated using ASHRAE Thermal sensation scale which has been proposed earlier by Fanger (1970) for the measured data. Further Predicted Percentage Dissatisfied (PPD) was used to estimate the thermal comfort satisfaction of the occupant. The study revealed that 70% of the students’ population at the classroom is dissatisfied with the thermal comfort. Keywords: Thermal comfort, school, PMV, PPD INTRODUCTION The importance of maintaining adequate indoor air quality in schools is recognised as being a contributing factor to the learning performance of pupils (Fisk, 2000; Shandell et al., 2004; Colay and Greeves, 2004). Recently, a study based on both a subjective questionnaire survey and objective test scores concluded that learning performance improved with a decrease in the percentage of pupils dissatisfied with the indoor air environment (Kameda et al., 2007). Another study, based on five independent experiments carried out in mechanically ventilated classrooms, concluded that improving classroom conditions should be an urgent educational priority (Wargocki, 2006). The study showed that doubling the ventilation rate to 10 l/s per person would