Ventilation Potential: Examining the Effects of Growing Densification in the Tropics

The density of Dhaka is increasing exponentially, and with it the demand for residentialaccommodation. Rapid densification is increasing hard surfaces and changing the urbantexture, thereby escalating heat absorption. This intensifies dependency on valuableconventional energy resources, for thermal comfort.Research shows that regional climatic data differs markedly from localised microclimaticeffects within the built environment. In built-up residential areas of the city there is the lack ofnatural wind flow, one of the most important ingredients for comfort during the warmmonsoons. Electricity is growing costlier day by day and its supply is erratic, while loadshedding to balance the supply and demand, is very common.This paper presents the findings of an ongoing research, to investigate the effects of growingdensification in the city on the potential for natural ventilation. The work is based on thepremise that the effect of variation in density will be reflected in the comparative differencesin qualities of the thermal environment (indicated by the temperature and wind speedmeasurements) in the different residential areas of Dhaka. Higher temperatures in the denserparts of the city may be attributed to larger daytime absorptions and slower night-timecooling, and lack of breeze to distribute the unevenness. In conclusion some passive measuresare suggested to rectify the negative aspects of the environment.