On-Site Capture Efficiency of Kitchen Range Hood Based on Particle Diameters and Exhaust Flow Rates

Particles generated from cooking activities are the biggest contributor to the concentration of indoor particles in most homes, and they are not easily removed without natural or mechanical ventilation. As more focus is directed on human health, kitchen range hoods have drawn increasing attention and their performance in various conditions needs to be evaluated. Consequently, in this study, we performed measurements to establish the particle capture efficiency of a kitchen range hood for various particle diameters at different exhaust flow rates. The kitchen particle concentration generated by bacon-frying was measured while maintaining the differential pressure of the kitchen and adjacent zone at 0–1 Pa through the supply of outdoor air. Since the supply fan had no filter and the walls of the of the testbed were not sufficiently airtight, which is as same as typical dwellings, so an estimation of the particle concentration from the supply air or penetrated air had to be subtracted from the measured concentrations, to establish the concentration generated from bacon-frying alone. Within the particle diameter range of 0.3–10 μm, smaller particles with higher kitchen hood exhaust rate generally exhibited better capture efficiencies. Although the capture efficiencies at both exhaust rates (250 m3/h and 350 m3/h) were almost identical for similar particle diameters, (except for the 10 μm), the peak concentration and the time taken returning to the background concentration were reduced at an exhaust rate of 350 m³/h.