Proceedings of 7 th Windsor Conference: The changing context of comfort in an unpredictable world Cumberland Lodge, Windsor, UK, 12-15 April 2012. London: Network for Comfort and Energy Use in Buildings, http://nceub.org.uk Validating Fanger's PMV model in a “real” field study. Mohammad Kotbi 1 , Steve King and Deo Prasad Faculty of the Built Environment University of New South Wales Sydney, NSW, Australia Email: z3108183@zmail.unsw.edu.au 1 Lecturer at King Saud University, Saudi Arabia, PhD candidate in the University of New South Wales, Australia. Abstract Fanger's predicted mean vote (PMV) model of thermal comfort perception is criticised for the consistency of its results with the actual mean vote (AMV). This is mainly because Fanger‟s PMV model assumes some particular circumstances that hardly ever occur in real world experience, such as the similarity of personal variables and other psychological parameters. However, a broader ongoing research project examining thermal comfort in mosques in Riyadh, Saudi Arabia, has provided an unusually well formed vehicle to validate the PMV model in a real field study. Comparing the results of the predicted mean vote (established by monitoring the relevant variables to match the outputs of the application of PMV model), and the actual mean vote(s) of this real field study is thought to be the most appropriate basis for the validation of the PMV model. In this paper, the overall context of the mosque as the case study is described. The methodology and the methods including the instrumentation and the questionnaire are highlighted. Preliminary results of monitoring and perception surveys are reported, including some analysis of the PMV/AMV relationship. Keywords Thermal comfort, PMV, AMV, Validating, Field study, Mosque. Introduction Fanger‟s PMV model uses four environmental variables, air temperature, relative humidity, air velocity and mean radiant temperature MRT, in addition to two personal variables, clothing insulation and metabolic rate. These variables are used as inputs to predict the mean comfort vote of a group of subjects on the ASHRAE seven points thermal sensation scale (Fanger, 1970). Even though the model is the most commonly adopted in academic research, it has been criticised in much of the same work regarding the consistency of the results when applying the model in a real world field study. To be correctly validated as it is originally developed; the model needs to be tested in a steady slate environment, a controlled single space. The metabolic rate of the occupants is always generalized as one input, which is misleading because it is