Indices of Thermal Comfort Developed from Field Survey in Brazil

Xavier, A.A.P.; Lamberts, R.
ASHRAE Transactions

The indices of thermal comfort that constitute international standards, such as ISO 7730 and norms suggested by technical publications such as ASHRAE Fundamentals, are PMV, PPD, and T{sub oc}. The aim of this paper is to present similar indices developed from field studies. The studies were made at a school in Florianopolis, Brazil, and consist of more than 1,200 data points. The environmental variables were measured, and the metabolic rate and the thermal insulation of the clothing were estimated from existing tables. Thermal sensation votes were collected for all the students by means of specific questionnaires. The main conclusions are: There is good agreement between the sensations related by the subjects and those obtained from predictions determined by regression analysis; the studies provide one with a different understanding of dissatisfaction with a thermal environment; and when determined from the votes of dissatisfied people, the comfort temperature offers the advantage of showing one the percentage of people who are not comfortable.