Investigating the age of air in rural Indian kitchens for sustainable built-environment design

Abstract

The “freshness” of indoor air quality is a determinant of health. In India, solid fuel burning for cooking in rural kitchens causes a considerable amount of household air pollution (HAP) leading to an adverse effect on health. The health effects of HAP are aggravated when polluted air takes a long time to be flushed out of the cooking area, which is directly related to the indoor ventilation rate. This study attempts to determine building parameters of rural kitchens in India, through a field survey instrument, that enable a reduction in the age of air without the introduction of any external driver such as improved cookstoves, or chimneys. The indoor airflow pattern and the age of air were determined through field survey and steady state RANS simulations of actual naturally ventilated rural kitchens. The generated local mean age of air profile of these kitchens were correlated with the built parameters like opening to wall ratio (OWR), aspect ratio, volume and slenderness ratio, to determine the critical dependencies of these parameters to the freshness of indoor air quality. This study showed that age of air reduced with higher OWR and height of the kitchens while it increased with larger aspect ratio or depth of the kitchens and volume. Based on the results this study identifies the critical building parameters that can enable sustainable design strategies without the introduction of clean fuel or improved cookstoves which may be unaffordable, culturally unacceptable, or inaccessible. The intention is to contribute in rational design decision making for creating sustainable rural habitat.