Long-term application of low-cost sensors for monitoring indoor air quality and particle dynamics in a commercial building

Human exposure to indoor particles has been associated with increased rates of morbidity and mortality. To develop efficient particle control measures in indoor environments, there has been an increasing demand for the use of low-cost particle sensors towards indoor air quality applications. However, few studies have examined the potential application of low-cost particle sensors for monitoring indoor air quality and particle dynamics under a long-term deployment in commercial buildings. Given this background, we conducted a case study of six-month field investigation on the use of low-cost sensors for evaluating particle emission, concentration, and removal in an office building. Our results illustrate the necessity of improving control strategies for fine particles <1 μm in commercial buildings (e.g., utilizing high efficiency particle filters). Deploying low-cost particle sensors within an air handling unit and occupied spaces could be a quick and simple approach for monitoring particle filtration effectiveness of a mechanical ventilation system. Furthermore, this study suggests that coupling low-cost particle sensors with CO₂ measurements can offer informative data for analyzing particle emissions associated with occupant activities. Our results reveal that particle resuspension due to occupants can be an important emission source for particles >5 μm in office environments. The study findings could help future research and applications of low-cost sensors in monitoring indoor air quality in commercial buildings.