Measurements of Capture Efficiency of Range Hoods in Homes

A major source of pollutants in homes is cooking and as homes get tighter in the pursuit of lower energy use (particularly near zero energy), the concentration of cooking pollutants increases. The best way to remove cooking pollutants is to use a range hood above the cooking surface. Ideally, we want a range hood to use little energy and have high capture efficiency to minimize the required air flow to capture the cooking pollutants. Currently there are no standards for rating range hoods for capture efficiency In this study, measurements of range hood capture efficiency were made a tight kitchen-room built in a laboratory chamber, and a methodology for standardizing measurement of capture efficiency was developed. The results for a wall mounted range hood, showed that up to half of the cooking pollutants were not captured at a flow rate of 230 m3/h. A more detailed set of measurements mapped the pollution distribution in the room, and showed that the pollutants escape more at the sides of the cooktop. These preliminary results suggest that more measurements should be conducted investigating the capture efficiency at different pollutant source temperature, size and location, and for different range hood type and mounting height.