Study for flow and mass transfer in toilet bowl by using toilet seat adopting odor/bacteria suction feature

Recently, concerns for the indoor environment have significantly increased due to demands for a better quality of life. The bathroom has the poorest air quality in a building; nevertheless, it usually requires the best cleanliness. Most contamination sources in a bathroom are the unpleasant odor and bacteria due to feces. Instead of an air ventilation system that circulates all of the bathroom air, authors investigate numerically and experimentally a system that entrains the source from a toilet bowl and blocks the source's outflow. The system is simply installed inside the toilet seat. The effects of the suction flow rate, the suction hole size, and the number of suction holes are tested. The flow and concentration in the toilet bowl are numerically visualized. In addition, experimental results are in good agreement with the numerical results. Finally, the best conditions, a combination of the suction hole size of 4 × 4 mm2 and rear two pairs open are obtained.