Thermal comfort in low-cost dwellings : a case study in Curitiba, Brazil

The main goal of the present study was to determine thermal comfort parameters for dwellers of low-cost houses for a given set of indoor environmental conditions. 112 people living in over 60 dwellings were interviewed, according to a comfort questionnaire where information regarding age, sex, clothing, level of activity, thermal sensation and preference of the subjects was collected. Environmental factors such as air temperature and humidity were simultaneously registered with T/RH data-loggers. Results were then analyzed by comparing subjective and environmental factors. Data consistency was checked out for specific parameter sets and the corresponding neutral, comfort temperatures were obtained by means of regression analysis. For the complete data set, a neutral temperature of 20.42C was achieved (indoor temperatures varied from 13.7C up to 26C plotting air temperature and humidity in Givonis Building Bioclimatic Diagram resulted in 29.5% of the hours in a cold situation and 70.5% within the comfort zone). Differences in the neutral temperature were observed between masculine and feminine, young and elderly subjects and for different sets of activity level, clothing and relative humidity. The relatively low neutral temperature obtained by this research showed a good correspondence to the results of a previously conducted pilot-study which generated a neutral temperature of 20.8C. It may be concluded that low-income dwellers in Curitiba regarding its cold climate and the fact that local low-cost houses are usually neither insulated nor heated in winter accept temperature conditions which are closer to the lower comfort limit, defined for developing countries as 18C.