Investigating thermal comfort models

Abstract

Arguably, behaviour adaptation and psychological factors are the main explanations for incorrect predictions of thermal sensation in naturally ventilated indoor environments. While these factors are seemingly difficult to estimate or prevent, how can this argument be validated? This research project has defined a unique setting which includes a special building typology with unique context, which provides real-life field study that could minimise these factors. Furthermore, a successful field study that could minimise the adaptation factors in the first place can validate the PMV model, which would be an important additional finding of this research. For the general benefit of research in this domain, the studies that provided the basis for the inapplicability of Fangerâ s PMV model in naturally ventilated interiors are reviewed. It is observed by several researchers that the correlation between the predicted mean vote (PMV) and the actual mean vote (AMV) of thermal sensat ion in air-conditioned buildings, differ from the correlation in the case of naturally ventilated buildings. This is the most important argument that provided the basis for questioning the applicability of the Fangerâ s PMV model in naturally ventilated buildings, eventually strengthens an adaptive model. There are different factors that have been suggested to be the possible explanation for this observation; examples of such are behaviour adjustments and psychological expectation. However, these suggested explanations have never been validated. The research hypothesis is, as the behaviour adjustments and psychological expectations are the only explanation for the clear difference between the correlation of predicted mean vote PMV and actual mean vote AMV in air-conditioned and the correlation of PMV and AMV in naturally ventilated buildings, if by any means, the behaviour II adjustments and psychological expectation were minimized or eliminated, then the correlation between PMV and AMV should be similar in both air-conditioned and naturally ventilated buildings. The unique setting for the real world field study is proposed to be a mosque in Riyadh Saudi Arabia. The methodology of the research is to conduct a thermal comfort study in a mosque in Riyadh, Saudi Arabia, to compare the Predicted Mean Vote â by applying Fanger PMV modelâ with the Actual Mean Vote of the occupants by conducting a thermal sensation survey. This comparison was done in two modes: while the mosque is naturally ventilated in the winter, and while the mosque is air- conditioned in the summer, to establish the basis for comparing the correlation between the two modes. With the factors responsible for the difference of the correlation between airconditioned and naturally ventilated mode being minimized in this case study, the level of PMV/AMV correlations in the air-conditioned mode and the naturally ventilated mode are supposed to be noticeably similar. That would then provide real field validation study for the factors that arguably responsible for the difference in correlation between air-conditioned and naturally ventilated buildings in the meta studies in the field of thermal comfort. In this dissertation, the unique parameters of such a case study are discussed, and research methods, instrumentation and survey components of the research are explained. The details of the field study are addressed, including the application of the PMV model, reporting the actual mean vote (AMV) of thermal comfort sensation of the subjects and the analysis of the collected data.