The influence of thermal comfort conditions on user's exposure time in open spaces

This paper discusses the influence of the user thermal comfort conditions on the time spent in open spaces through a case study performed in Bauru, Sao Paulo, Brazil. The study was carried out in two subspaces of a zoo, under warm and wet conditions. Although the subspaces had different levels of shading, they were of similar interest to visitors. The methodology adopted the collection of objective (air and globe temperature, humidity, and velocity) and subjective data (by application of questionnaires), for a sample of 174 users, and local observations with photographic records each 3 min. Data and images obtained enabled the characterization of the local microclimates and contributed to evaluate (1) user's thermal perception (7-point scale), (2) affective evaluation of the thermal comfort (4-point scale), (3) thermal preference (7-point scale), (4) calculated thermal perception (through PET (physiological equivalent temperature) index), and (5) user's exposure time in each subspace. The great contributions of this work were to identify that in the subspace with bigger shading and less rigorous microclimatic conditions, users had exposure time longer than another more exposed to solar radiation and to validate a method to measure user's exposition time through sequential photos. These results contribute to a discussion that has yet been little explored in the literature of the area, proving the strong influence of the thermal comfort conditions in the users' exposure time in open spaces.