Application of a high-efficiency cabin air filter for simultaneous mitigation of ultrafine particle and carbon dioxide exposures inside passenger vehicles.
Modern passenger vehicles are commonly equipped with cabin air filters but their filtration efficiency for ultrafine particle (UFP) is rather low. Although setting the vehicle ventilation system to recirculation (RC) mode can reduce in-cabin UFPs by ∼ 90%, passenger-exhaled carbon dioxide (CO2) can quickly accumulate inside the cabin. Using outdoor air (OA) mode instead can provide sufficient air exchange to prevent CO2 buildup, but in-cabin UFP concentrations would increase. To overcome this dilemma, we developed a simultaneous mitigation method for UFP and CO2 using high-efficiency cabin air (HECA) filtration in OA mode. Concentrations of UFP and other air pollutants were simultaneously monitored in and out of 12 different vehicles under 3 driving conditions: stationary, on local roadways, and on freeways. Under each experimental condition, data were collected with no filter, in-use original equipment manufacturer (OEM) filter, and two types of HECA filters. The HECA filters offered an average in-cabin UFP reduction of 93%, much higher than the OEM filters (∼ 50% on average). Throughout the measurements, the in-cabin CO2 concentration remained in the range of 620-930 ppm, significantly lower than the typical level of 2500-4000 ppm observed in the RC mode.
Department of Environmental Health Sciences, Jonathan and Karin Fielding School of Public Health, University of California , Los Angeles, California 90095-1772, United States.
Eon S
ES
Lee
Yifang
Y
Zhu
D061808:Air Filters; D000393:Air Pollutants / Q000032:analysis; D000397:Air Pollution / Q000517:prevention & control*; D001334:Automobile Driving; D002245:Carbon Dioxide / Q000032:analysis*; D004781:Environmental Exposure / Q000517:prevention & control*; D005374:Filtration; D018986:Motor Vehicles; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis; D053260:Soot / Q000032:analysis; D013997:Time Factors; D014691:Ventilation
D000393:Air Pollutants; D052638:Particulate Matter; D053260:Soot; D002245:Carbon Dioxide