Volume 14, No. 3, April 2014, Pages 1066-1073 PDF(285 KB)
Investigation of Air Humidity Affecting Filtration Efficiency and Pressure Drop of Vehicle Cabin Air Filters
Bin Xu1,2, Ya Wu1, Zhongping Lin3, Zhiqing Chen3
1 Department of Environmental Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
2 State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, 1239 Siping Road, Shanghai 200092, China
3 School of Mechanical Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
Vehicle cabin air filters are exposed to humid air more frequently than any other air filters during routine use. The filtration performance of several commercially-available cabin air filters was investigated, along with the humid exposure period, using laboratory-based measurements. The averaged filtration efficiency and pressure drop were measured at ~70% and 75 Pa, respectively. Significant increases in filtration efficiency (up to 15%) and pressure drop (up to 250 Pa) were observed as the humid exposure time increased. Filtration efficiency increased ~15% and pressure drop increased 250 Pa as 140 g water was absorbed, which represents ~60 minutes humid exposure at a relative humidity of 90%. The pressure drop increased significantly at the beginning of the humid exposure due to the greater water absorption capacity of dryer dust in the filter. The dust load had a significant effect on the changes in filtration efficiency and pressure drop. The filtration efficiency and pressure drop of the 12-month used filter increased 2 times faster than that of the new filter at the same exposure conditions. The filtration efficiency and pressure drop were explicitly expressed as functions of the water absorption mass in the filter. Two coefficients were empirically derived and successfully accounted for the effects of humid exposure on filtration efficiency and pressure drop.
Cabin filter; Particle filtration; Humid air; Filtration efficiency; Pressure drop.