A.D.L. Costa, L.C. Labaki, V.M. Dantas de Araujo
Year:
2005
Bibliographic info:
Passive and Low Energy Cooling for the Built Environment, May 2005, Santorini Greece

This paper describes a study, developed in the district of Petropolis in the city of Natal, Brazil. The aim of the study was to investigate the influences of city urban form in the climate and its correlation with the thermal sensation of the users of open spaces. The method consists of drawing maps of the study area (based on Katzschner, 1997) including topography, building height, land use, green areas, soil pavement, as well as measurement of the environmental variables: air temperature, relative humidity, direction and wind speed, for a comparative study. Besides, local users of the district were interviewed about their thermal sensations in the open space. For statistical analysis, data were collected at ten points, eight within the district and two in climatological stations outside the district, in three periods (in 2000 and 2002), in four consecutive days for each measurement (from Sunday to Wednesday). The hours with lowest and highest temperatures in the city were chosen for measurement - 6:00 a.m. and 1:00 pm, respectively. At the same time interviews were carried out with users of the open spaces, totaling 171 valid formularies. The urban form showed a rather leveled topography, great diversity of land use and building height, with an area mostly occupied with high buildings, very little green area and soil almost completely impermeable. The statistical analysis showed high temperature and humidity levels. The wind direction is predominantly Southeast with extremely variable speed. It was observed that this district is hotter and less ventilated than outside; besides, most users said that they felt uncomfortable in the local environmental conditions. The results of the analysis generated a zoning for the district with recommendations for soil occupation, as well as some discussion about the comfort parameters, including the proposal of limiting temperature and humidity regions for the thermal comfort in the open spaces.