CH-24-C017 - Analysis of Residential Kitchen Ventilation with a Gas Stove—A Mass Balance Approach

Cooking activities as well as the combustion of natural gas through gas stove burners produce indoor pollutants in homes. Depending on the exposure levels these pollutants can pose health hazards to occupants. Kitchen ventilation can potentially reduce the occupant exposure. This study with the help of the mass balance approach evaluates the impact of exhaust air flow rate, delay in starting the exhaust fan after starting the burner, duration for which the exhaust fan is left operating after the burner is turned off, and the size of a kitchen on the transient well-mixed concentration of Nitrogen Dioxide (NO2) and resulting occupant exposure. These analyses indicate that the kitchen ventilation should operate with the exhaust flow rate of at least 100 cfm (47 L/s); the exhaust fan should be started within ten minutes of starting the burners (cooking); and the exhaust fan should be kept on for at least five minutes after turning the burner off (after cooking). It further indicates that the homes with open floor plans (larger kitchens) would experience relatively lower exposure than the small enclosed kitchens. The mass balance approach assumes instantly well-mixed conditions. Since it is a boundarylimited approach it cannot predict the spatial variations of pollutants within the space. To predict the concentration in the breathing zone of occupants a detailed three-dimensional transient Computational Fluid Dynamics (CFD) analysis is required.