Semester

Fall

Date of Graduation

2020

Document Type

Dissertation

Degree Type

PhD

College

Statler College of Engineering and Mineral Resources

Department

Industrial and Managements Systems Engineering

Committee Chair

Warren Myers

Committee Member

Gary Winn

Committee Member

Kenneth Currie

Committee Member

Ziqing Zhuang

Committee Member

Anna Allen

Abstract

One of the aims of installing ventilation filters in a car is to prevent vehicle occupants from inhaling potentially harmful aerosols emanating from the environment. Vehicle cabin filters are essential in ensuring that a vehicle's air conditioning system provides clean air to its occupants. The purpose of the cabin filter is to improve air quality inside the car to provide better comfort and better protect occupants from experiencing unwanted respiratory problems. Using cabin filters in air conditioning systems is a common practice in modern vehicle manufacturing. Scientists and engineers are continually seeking new ways of improving the efficiency and effectiveness of cabin filters.

First, a laboratory experiment was conducted to test the mean efficiency for five different types of cabin air filters, which were separated into two groups based on the average surface area of each group. Each group was tested under three different concentrations (40,000, 60,000 80,000) particles/ cm3 as well as three different face velocities (4.3, 8.8, 13.3) cm/s for group one and face velocities (2.6, 5.3, 7.9) cm/s for group two, respectively. The purpose of this study was to evaluate the filtration efficiency of car air conditioning filters as a function of aerosol concentration and challenge face velocity. In addition, this study was also to simulate construction applications, since most construction equipment have cabins that should isolate workers from dust that the construction equipment makes. A three-way ANOVA was analyzed in JMP Software. The analysis showed that the types of filter, particle concentrations, and face velocities significantly (p<0.05) effected the mean efficiency for both groups. The results for each group indicated that the highest mean efficiency across all filter types occurred at the lowest face velocity and the lowest mean efficiency was at the highest face velocity. Further, the mean efficiencies always decreased when the face velocities and concentration increased.

Finally, a second study, Study II, was conducted to evaluate the filtration efficiency of the five car air conditioning filters during city and highway driving. Test conditions during city or highway driving included seven ventilation fans setting and two different car speeds (50 and 70 mph). This study investigated the efficiency of current car cabin filters and their effectiveness in filtering out particles in the air such as viruses, especially COVID-19. In addition, the major application areas that challenge COVID-19 are school buses, personal cars, taxis via different platforms such as Uber, and industrial vehicles. Study II sought to provide an insight to the combined operational efficiency of five types of cabin filters from particles ranging of 10 to 10,000 nanometer in normal operating conditions. The results from this investigation may be considered for development of standards to improve cabin air filters in future.

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