Durham School of Architectural Engineering and Construction
Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research
First Advisor
Josephine Lau
Date of this Version
3-2023
Document Type
Thesis
Citation
A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science
Major: Architectural Engineering
Under the supervision of Professor Josephine Lau
Lincoln, Nebraska, March 2023
Abstract
Meat processing plants are linked to the rapid spread of COVID-19 cases. A related literature review shows a lack of proper ventilation standards for the meat processing plants for workers’ health and safety. Ventilation rates in these plants are considered adequate if the meat products are unadulterated. Thus, the air distribution and ventilation rate experiments were conducted in three meat processing plants. These measured ventilation rates were either compared to ASHRAE Std. 62.1 (2019) for a similar space or the design values provided by the plant’s administration. The measured values were low in common spaces, such as the cafeteria and locker rooms. In addition, the total airflow rates from the diffusers also characterize the air distribution. A modified Wells-Riley model was used to calculate the COVID-19 airborne infection risk for two selected spaces to compare different engineering solutions, such as installing portable air cleaners, using ultraviolet lights in the upper room and in-duct, better filtration systems, and enhanced ventilation rates. Infection risks in a single space were used to rank these solutions. However, a worker during a whole shift moved from different spaces for different time durations. Therefore, six case studies were simulated to compare the differences between schedules, ventilation rates, and shedder strength. In two baseline studies, based on regular shifts and existing ventilation conditions, the airborne infection risks were about 42 % and 8 % for high and low shedders, correspondingly. Study II and Study II-L comprised a hypothetical staggered schedule with the existing ventilation conditions, and the relative reductions of infection risks were 23% and 28%, respectively, when compared to the corresponding baselines. Study III and Study III-L used the staggered schedule and enhanced ventilation and found the relative reductions of infection probability were about 43% and 49% respectively. Therefore, administrations should recognize the mentioned engineering solutions and use a staggered schedule to mitigate the infection risks in the meat processing plants.
Advisor: Josephine Lau
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