The Role of Portable Air Purifiers and Effective Ventilation in Improving Indoor Air Quality in University Classrooms
Abstract
:1. Introduction
2. Methods
2.1. Measurement Sites and Protocol
2.2. Instrumentation
2.3. Additional Calculations
2.3.1. Indoor Particle Penetration (P) in the Set of Classrooms
2.3.2. Air Purifier’s Efficiency in Classroom 3
3. Results and Discussion
3.1. Indoor Monitoring of PM, PN, and CO2 Concentrations in the Set of Classrooms
3.1.1. Indoor CO2 Levels
3.1.2. Particle Mass and Number Concentrations and Indoor-to-Outdoor Ratios inside the Classrooms
3.2. Indoor Monitoring of PM, PN, and CO2 Concentrations in Classroom 3 in the Presence of Indoor Particle Pollution Source
3.2.1. PM and PN Decay Rates with and without the Use of Air Purifier at Different Volumetric Flow Rates
3.2.2. Removal Efficiency as a Function of Particle Size
4. Summary and Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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No. | Classroom | Building Name | Number of Students | Room Height (m) | Floor Area (m2) | Volume (m3) |
---|---|---|---|---|---|---|
1 | OHE136 | Olin Hall (OHE) | 21 | 3.05 | 86.12 | 262.50 |
2 | RTH 105 | Tutor Hall (RTH) | 7 | 3.05 | 97.73 | 297.89 |
3 | SGM 226 | Seeley G. Mudd Building (SGM) | 8 | 3.05 | 63.64 | 193.97 |
4 | GFS 221 | Grace Ford Salvatori Hall (GFS) | 20 | 3.05 | 36.42 | 111.00 |
5 | GFS 205 | Grace Ford Salvatori Hall (GFS) | 12 | 3.05 | 36.51 | 111.29 |
6 | KAP159 | Kaprielian Hall (KAP) | 20 | 3.05 | 37.63 | 114.68 |
7 | OHE 120 | Olin Hall (OHE) | 6 | 3.05 | 56.49 | 172.17 |
8 | KDC 236 | Glorya Kaufman International Dance Center (KDC) | 26 | 3.05 | 89.00 | 271.28 |
9 | THH 118 | Taper Hall (THH) | 22 | 3.05 | 76.83 | 234.18 |
PM2.5 Mass Concentration (PM) (µg/m3) | |||||||||
First Phase | Second Phase | Third Phase | |||||||
Indoor | Outdoor | I/O | Indoor | Outdoor | I/O | Indoor | Outdoor | I/O | |
Classroom 1 | 1.19 | 7.90 | 0.15 | 0.07 | 2.04 | 0.03 | 0.21 | 9.00 | 0.02 |
Classroom 2 | 0.31 | 8.2 | 0.04 | 0.48 | 46.01 | 0.01 | <LOD | 24.33 | NA |
Classroom 3 | 8.62 | 19.55 | 0.44 | 1.25 | 3.04 | 0.41 | 10.97 | 42.39 | 0.26 |
Classroom 4 | 1.29 | 10.60 | 0.12 | 0.61 | 9.56 | 0.06 | 2.03 | 28.22 | 0.07 |
Classroom 5 | 1.24 | 13.44 | 0.09 | 1.04 | 10.31 | 0.10 | 0.73 | 6.60 | 0.11 |
Classroom 6 | 1.00 | 5.63 | 0.18 | 0.15 | 2.75 | 0.05 | 0.77 | 22.93 | 0.03 |
Classroom 7 | 0.27 | 7.83 | 0.03 | <LOD | 4.08 | NA | <LOD | 11.67 | NA |
Classroom 8 | 0.95 | 5.69 | 0.17 | 2.99 | 33.91 | 0.09 | 2.20 | 60.25 | 0.04 |
Classroom 9 | 2.43 | 21.67 | 0.11 | 1.92 | 18.71 | 0.10 | 0.87 | 11.85 | 0.07 |
Particle Number Concentration (PN) (particles/cm3) | |||||||||
First Phase | Second Phase | Third Phase | |||||||
Indoor | Outdoor | I/O | Indoor | Outdoor | I/O | Indoor | Outdoor | I/O | |
Classroom 1 | 207.4 | 8523.5 | 0.02 | 90.6 | 4798.5 | 0.02 | 84.0 | 2972.8 | 0.03 |
Classroom 2 | 113.73 | 2290.07 | 0.05 | 165.87 | 5285.31 | 0.03 | 42.76 | 3672.92 | 0.01 |
Classroom 3 | 2328.7 | 6693.6 | 0.35 | 1800.0 | 5557.3 | 0.32 | 1917.8 | 7050.2 | 0.27 |
Classroom 4 | 258.6 | 5537.9 | 0.05 | 306.2 | 6704.9 | 0.05 | 253.8 | 6944.3 | 0.04 |
Classroom 5 | 345.6 | 8453.6 | 0.04 | 151.0 | 8414.1 | 0.02 | 363.1 | 17704.5 | 0.02 |
Classroom 6 | 1389.0 | 14338.6 | 0.10 | 299.1 | 12158.4 | 0.02 | 89.4 | 10312.7 | 0.01 |
Classroom 7 | 76.36 | 6215.27 | 0.01 | 52.33 | 4425.42 | 0.01 | 53.41 | 5573.16 | 0.01 |
Classroom 8 | 388.0 | 13783.6 | 0.03 | 220.0 | 7050.2 | 0.03 | 90.4 | 5807.8 | 0.02 |
Classroom 9 | 1100.2 | 17763.5 | 0.06 | 673.5 | 14862.2 | 0.05 | 543.5 | 15294.1 | 0.04 |
Theoretical K (h−1) | Experimental K (h−1) | |
---|---|---|
Without purifier (Knatural) | 4.32 | 4.74 ± 0.15 |
Purifier at low setting (Kpurifier (low)) | 5.22 | 5.09 ± 0.13 |
Purifier at high setting (Kpurifier (high)) | 6.90 | 6.70 ± 0.33 |
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Aldekheel, M.; Altuwayjiri, A.; Tohidi, R.; Jalali Farahani, V.; Sioutas, C. The Role of Portable Air Purifiers and Effective Ventilation in Improving Indoor Air Quality in University Classrooms. Int. J. Environ. Res. Public Health 2022, 19, 14558. https://doi.org/10.3390/ijerph192114558
Aldekheel M, Altuwayjiri A, Tohidi R, Jalali Farahani V, Sioutas C. The Role of Portable Air Purifiers and Effective Ventilation in Improving Indoor Air Quality in University Classrooms. International Journal of Environmental Research and Public Health. 2022; 19(21):14558. https://doi.org/10.3390/ijerph192114558
Chicago/Turabian StyleAldekheel, Mohammad, Abdulmalik Altuwayjiri, Ramin Tohidi, Vahid Jalali Farahani, and Constantinos Sioutas. 2022. "The Role of Portable Air Purifiers and Effective Ventilation in Improving Indoor Air Quality in University Classrooms" International Journal of Environmental Research and Public Health 19, no. 21: 14558. https://doi.org/10.3390/ijerph192114558