Evaluation of Outdoor Particle Infiltration into Classrooms Considering Air Leakage and Other Building Characteristics in Korean Schools

Ye Seul Eom,Hee Won Shin,Dong Hwa Kang,Bo Ram Park

doi:10.3390/su13137382

Abstract

We analyzed the effects of air leakage and other building characteristics on outdoor particle penetration in classrooms. The building characteristics including air leakage of 12 Korean schools were investigated, and onsite measurements were conducted to estimate the outdoor particle infiltration. The correlations among variables associated with air leakage and building characteristics and outdoor particle infiltration were analyzed using the Pearson correlation analysis and linear regression. The effective leakage area (ELA) of classrooms varied highly from 340.8–1566.9 cm2, and a significant disparity in the air leakage characteristics among the classrooms appeared. The results of onsite measurement revealed that the average ELA was larger in the corridor side with an ELAcorridor-side of 264.7 cm2 than in the outdoor side (ELAoutdoor-side of 93.1 cm2). Results of correlation analysis indicated a high correlation (r = 0.68~0.78, p-value < 0.05) between the size resolved outdoor particle source (P × λ) and specific ELA. Particularly, a strong linear relation (R2 = 0.69~0.71) with specific ELAcorridor-side was seen. Results suggest that cracks between windows and doors in the corridor side considerably affect outdoor particle penetration. These results indicate the importance of improving the airtightness of not only the building envelope but also the inter-zonal walls for effectively reducing the outdoor particle infiltration into classrooms.

Highlights

Several variables associated with air leakage characteristics, other building characteristics, and outdoor particle infiltration were selected
(1) As variables related to air leakage characteristics, effective leakage area (ELA), specific ELA, air change per h at 50Pa (ACH50 ), flow coefficient (C), and flow exponent (n) in the power-law expression were selected, and the data were collected through field experiments in classrooms to investigate the analytical variables (2) As variables related to other building characteristics, built year, floor area, envelope area, and frame material were selected, and the values of these variables were investigated through field measurement
The results demonstrate that outdoor particle penetration in classrooms is likely to occur through the leakage pathway in corridors due to the fact that ELAcorridor-side is larger than

Summary

Introduction

With increasing outdoor particle concentration, interest in reducing health risks of respiratory and cardiovascular systems due to exposure to particulate matters is growing [1,2]. Children and adolescents having incomplete immune systems and lower weights than those of adults react more sensitively when exposed to equivalent particulate matters [3,4,5,6]. Classrooms have a high occupancy density with 20–30 students staying for long hours in areas of approximately 46–68 m2 [7,8,9]. Students may be exposed to a high particle concentration as they spend 8–10 h in classrooms per day [10,11,12,13,14]

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Conclusion