The fuzzy set theory for analysing thermal comfort

Researchers involved in studying problems concerning the built-up environment face an objective complexity, of easy instrumental evaluation, and a subjective complexity which is psycho-physiological concerning human beings with different individual reactions to the same exposure conditions. We are dealing with quantitative data, made up of measured physical quantities, with qualitative data made up of the comfort status at an individual level, giving the correct relevance to the latter, if the comfort requirements of people to whom the built-up environment is addressed, are seen as priority. Considering the thermohygrometrical aspect within the environmental comfort evaluation, this paper looks into the possibility to apply the fuzzy set theory to deal with subjective data, which are imprecise and non-absolute in themselves. In fact, the fuzzy set theory allows use of linguistic variables that fit better than numerical variables in representing human behaviours. Application is proposed to a real case concerning a university building, for which environmental data, collected during the summer and winter seasons, and subjective data, collected by questionnaires, are available. The aim of the present study is to compare the results of a fuzzy analysis with the results obtainable from a traditional analysis, to favour the qualitative approach compared to the quantitative one in diagnosing indoor thermal comfort. Topic: 3 (applications in community buildings) Scope: thermal comfort analysis Originality: fuzzy set theory application Completeness: a real application is considered