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Developing a method to monitor thermal discomfort response variability

The need to identify occupants behavioural-responses to thermal discomfort during the heating season has become one of the priorities in the quest to reduce energy demand. The current models have long been associated with peoples behaviour by predicting their state of thermal comfort or rather discomfort. These assume that occupants act upon their level of discomfort through two types of responses: involuntary mechanisms of thermoregulation, and behaviouralresponses. This research seeks to investigate the variability of occupant self-reported and observed behavioural-responses in residential buildings during the heating season. The first part of the research reviews the current standard models and reports on a global sensitivity analysis of the models as described in standards and guidelines. The predictive models appear to be most sensitive to the personal variables, metabolic rate and thermal insulation of clothing. In field studies these personal variables are often estimated with a significant degree of error, and in building simulation studies they are given constant values as a function of the season and the building or room types. To address these two issues, this research introduces a mixed-method framework drawn from psychological and physiological studies. Twenty residents living in nineteen dwellings were monitored over a period of ten consecutive days, in the South-East of England during the winters of 2012 and 2013. Results from this experimental investigation enabled probability distributions for the two personal variables to be drawn. When combining the estimated activity and clothing levels with the environmental monitoring results, the predicted mean votes are substantially below those assumed in standards. This suggests that occupants in this study may be engaging in other adaptive behaviours, not currently accounted for within the standard models. The second part of the research focuses on identifying these adaptive behaviours. One of the key issues is to gather accurate measurements while using discreet observatory methods to have minimum impact on peoples behaviour. Drawing methods from thermal comfort research and psychology, the empirical study undertaken also allows for the creation of a threetiered framework mapping behaviour-responses to cold sensations, consisting of (1) increasing clothing insulation level, (2) increasing operative temperature by turning the heating system on/up, and (3) increasing the frequency, duration and/or amplitude of localised behaviour responses, including for example warm food or drink intake, changing position, changing location within the same room or changing room. Using content analysis and automated segmentation, occupant-self-reported and observed diary responses to cold thermal discomfort were compared, with results showing a marked difference between them. Theoretically, this research introduces a framework to monitor thermal discomfort responses that incorporates a wider range of observed behaviours. Methodologically, this research demonstrates the efficacy of multi-method observational approaches for understanding discomfort responses. Substantively, this research highlights the need for researchers working in this field not to fall into the gap between what occupants say and what occupants do.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:668443
Date January 2015
CreatorsGauthier, S. M. S.
PublisherUniversity College London (University of London)
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://discovery.ucl.ac.uk/1468727/

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