Natural ventilation in dense residential areas: studying alternatives

The provision of adequate naturally generated airflow is a vital component of energy-efficienthealthy buildings. Increasing densification in cities of today acts as a dominant influence onthe wind regime, diverting and obstructing natural wind flow to unpredictable levels.Localized air movement is often inadequate and vastly different from regional magnitudes anddirections and cannot be used as the basis of design. The pressures of population are expectedto continue unabated and timely interventions to offset the negative effects of proximity mustbe examined before development proceeds beyond redemption.This paper examines the role and adequacy of natural airflow in urban Dhaka and discussesalternatives at planning and detailed levels through examples. For healthy buildings,perceptible air movement is a pre-requisite for comfort in warm-hot-humid situations.Existing bye-laws govern development trends, and modifications are investigated to findsolutions to insufficient air movement. Lack of wind due to density is offset by designfeatures using stack pressures for generating air exchange.