Improving outdoor thermal comfort in warm-humid Guayaquil, Ecuador through urban design

Resumen

Many tropical cities suffer from increasingly higher temperatures due to both global and urban warming. Often the thermal conditions are worsened by poor urban design including lack of vegetation and shade in general. This paper deals with the outdoor thermal comfort in a newly built residential low and middle-income area in the warm-humid city of Guayaquil, Ecuador. The area has low-rise buildings (one or two storeys) with fairly wide streets and is practically devoid of vegetation. The aim of this study, which was based on field measurements and simulations, was to study to what extent thermal conditions could be improved through modifications of the urban design. A parametric study was performed with the numerical model ENVI-met in which the influence of parameters such as building height, shading devices and vegetation as well as surface colours was simulated. The measurements showed that the thermal conditions are very poor in general and far above normal thermal comfort limits, especially in the afternoon when the physiologically equivalent temperature (PET) reaches above 40°C. The simulations showed that the outdoor thermal conditions could be greatly improved by adding one or two storeys and/or by providing shading through trees or any type of horizontal shading devices. Such improvements led to a decrease of PET of up to 10°C. The results in this study give advice for a climateconscious design to urban planners and designers in Guayaquil.