Reduction of particulate matter concentrations by local removal in a building courtyard: Case study for the Delhi American Embassy School

Abstract

Exposure to particulate matter (PM) is strongly linked to human morbidity and mortality, where higher exposure entails higher all-cause daily mortality and increased long-term risk of cardiopulmonary mortality. The objective of this study is to demonstrate how and to what extent the local removal of PM2.5 can lead to reduced exposure for the children and teachers in the naturally ventilated courtyard of the American Embassy School (AES) high school building in Delhi. The study is performed by computational fluid dynamics (CFD) with the 3D steady Reynolds-averaged Navier-Stokes (RANS) equations in combination with the realizable k-ε turbulence model on a very high resolution grid. First, CFD validation is performed using wind-tunnel experiments of the flow pattern in and above a generic single street canyon. Next, the case study is conducted where four commercially available electrostatic precipitation (ESP) units are installed at different positions in the courtyard and the resulting performance is evaluated. PM2.5 dispersion is modeled with an Eulerian advection-diffusion equation.It is shown that the best ESP positions yield volume-averaged PM2.5 concentration reductions up to 34.1% in the courtyard's corridors, demonstrating the proposed mitigation strategy to be effective. Perspectives for further reduction of the PM concentrations and the related reduction of health risks are discussed.

Application of Improved CFD Modeling for Prediction and Mitigation of Traffic-Related Air Pollution Hotspots in a Realistic Urban Street

“…NO Beckerman et al (2008). With regard to PM 10 and PM 2.5 , it was already observed that the transport of particles with a 10 and 2.5 µm diameter is very comparable at higher air speeds, but can show differences at lower air speeds Vervoort et al (2019). Therefore, a more complete analysis of air pollution at the Turnhoutsebaan should involve both substances.…”

“…The results indicated that PM concentrations could be lowered 10-50 % in the vicinity of the parking garages. Vervoort et al (2019) modeled the removal of PM 2.5 with ESP from the naturally ventilated courtyard of the American embassy school in Delhi. Up to 34.1% overall volume-averaged concentration reduction was obtained as model result.…”

“…Similarly to Blocken et al (2016) and Vervoort et al (2019), the third and last mitigation measure, applicable for reducing the PM 10 concentration, consisted in the employment of commercially available ESP units. 5 ESP units were placed in strategic locations, adjacent to the street lanes at z = 1 m, where the pollutant tends to gather and stagnate, according to the outcomes of the simulation campaign for PM 10 .…”

Impact of Enclosure Boundary Patterns and Lift-Up Design on Optimization of Summer Pedestrian Wind Environment in High-Density Residential Districts

“…These related phenomena may negatively affect the sustainable development of urban residential districts. For instance, air stagnation due to a low wind velocity environment may prevent the evacuation of airborne pathogens [5,6]. During epidemic periods of infectious diseases, this issue is particularly prominent, and the concentration of pollutants poses a clear threat to public health safety [7].…”

Numerical Simulation of Haze-Fog Particle Dispersion in the Typical Urban Community by Using Discrete Phase Model

“…Besides, to evaluate the haze-fog particle dispersion and the effect of reducing particulate matter concentrations in real urban areas, some specific sites or buildings were investigated [17,25,26]. Vervoort et al [25] conducted the CFD simulations to investigate the effect of electrostatic precipitation devices on reducing PM 2.5 in the building at the American Embassy School Campus. It was found that the PM 2.5 was reduced by about 34% under the studied boundary conditions, and that method could effectively improve the local air quality.…”