Energy and Buildings 64 (2013) 317–322 Contents lists available at SciVerse ScienceDirect Energy and Buildings j ourna l ho me page: www.elsevier.com/locate/enbuild Thermal comfort assessment of large-scale hospitals in tropical climates: A case study of University Kebangsaan Malaysia Medical Centre (UKMMC) F. Azizpour ∗ , S. Moghimi, E. Salleh, S. Mat, C.H. Lim, K. Sopian University Kebangsaan Malaysia (UKM), Solar Energy Research Institute (SERI), Malaysia a r t i c l e i n f o Article history: Received 29 April 2013 Accepted 19 May 2013 Keywords: Thermal comfort Predicted mean vote (PMV) Thermal sensation vote (TSV) Effective temperature (ET*) Operative temperature (OT) Neutral temperature a b s t r a c t A field study on thermal comfort assessment was carried out in a large-scale hospital in a tropical climate. To evaluate thermal comfort, both subjective and objective measurements were performed. The data were collected from 10 various thermal zones of a hospital. In each zone the predicted mean vote (PMV) was calculated based on the Fanger theory. In addition, the thermal sensation vote (TSV) was calculated according to the survey to find the relationship between the Fanger model (PMV) and the occupants’ votes. In this study a strong relationship between PMV and TSV was found when R 2 = 0.88. According to this correlation the neutrality point shifted to +0.7 on the seven-point ASHRAE scale. Moreover, the neutral effective temperature (ET*) was calculated based on the TSV and PMV of 23.4 ◦ C and 21.3 ◦ C, respectively, indicative of compatibility with the adaptive theory. The results also demonstrate that the preferred effective temperature according to subjective assessment in this case study is 20.2 ◦ C. This analysis revealed that to the respondents of this study in 10 thermal zones the neutral temperature point is higher than global standards, while the preferred temperature is lower than standards and the neutrality point. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Thermal comfort guidelines are necessary to assist and guide building designers provide adequate indoor climates [1]. Proper indoor thermal conditions in buildings are important not only because the building occupants will be comfortable, but also because building energy consumption as well as its sustainability will be affected [1]. According to studies, a building with thermal comfort may increase the workers’ performance and productiv- ity and decrease the absenteeism rate [2]. The thermal comfort requirement in hospitals is particularly vital as patients are more sensitive to environmental factors than healthy people due to their fragile conditions and illnesses [3]. Prior studies have found that a suitable indoor air climate can shorten the patients’ length of stay at the hospital [4]. Two parameter types that influence thermal perception are environmental and personal factors. The main environmental fac- tors include air temperature, mean radiant temperature, relative humidity and air velocity, while the main personal factors con- sist of clothing insulation value and metabolic rate. These factors ∗ Corresponding author. Tel.: +60 3 8921 4596; fax: +60 3 89214593. E-mail addresses: fa.azizpour@gmail.com, saeed.moghimi@gmail.com (F. Azizpour). were researched in the 1970s and have lead to the development of thermal comfort standards and guidelines of the ASHRAE standard 55 [5]. Studies were carried out at Kansas State University by Ole Fanger and others who identified comfort perception as a complex interaction between various personal and environmental factors. Moreover, their findings showed a maximum number of satisfied people in a specified set of values. With the deviation of a value set, the percentage of satisfied people decreases. The two main ther- mal comfort indexes introduced are PMV (predicted mean vote) and PPD (predicted percent of dissatisfied people). PMV represents the predicted mean vote of people exposed to a certain environ- ment with the votes based on the thermal sensation scale (Table 1). In addition, PPD represents the percentage of unsatisfied people at each PMV. Table 1 illustrates the seven-point thermal sensa- tion scale. PMV sets up a thermal strain based on steady-state heat transfer between the human body and environment, and it specifies a vote to that amount of thermal strain. As the PMV deviates from zero which represents a neutral condition on either the positive or negative side, PPD increases. The PMV model is a steady-state model which only applies to people exposed to a constant condition and activity rate for an extended time. To date, PMV is the most widely used thermal comfort index. ISO (International Standard Organization) Standard 7730 [6] employs PMV limits as an express comfort zone classifi- cation. 0378-7788/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.enbuild.2013.05.033