Table 2.
Indoor and outdoor environmental factors and number of students on the day when the air samples were collected.
| Sample type | Sampled month | Classroom/outdoor | Number of students | Time of Natural ventilation (minute) | Operation time of Air cleaner (minute) | Temp (°C) | RH (%) | Wind velocity (m/s) | Precipitation (mm) |
|---|---|---|---|---|---|---|---|---|---|
| OC-Sa1 | October | Classroom 1 | 26 | 0 | 160 | 21.4 | 46 | - | - |
| OUT-Sa1 | October | Outdoor | - | - | - | 15.2 | 61 | 4.7 | 0 |
| OC-Sa2 | October | Classroom 2 | 23 | 170 | 0 | 23.7 | 45 | - | - |
| OUT-Sa2 | October | Outdoor | - | - | - | 18.8 | 60 | 6.8 | 0 |
| OC-Sb1 | November | Classroom 3 | 21 | 220 | 290 | 23.1 | 45 | - | - |
| OUT-Sb1 | November | Outdoor | - | - | - | 11.2 | 72 | 8.6 | 1.1 |
| OC-Sb2 | November | Classroom 4 | 22 | 0 | 285 | 22.6 | 41 | - | - |
| OUT-Sb2 | November | Outdoor | - | - | - | 9.3 | 64 | 5 | 0 |
| OC-Sb3 | November | Classroom 5 | 24 | 40 | 0 | 23.7 | 43 | - | - |
| OUT-Sb3 | November | Outdoor | - | - | - | 7.2 | 72 | 10.4 | 7.5 |
| UOC-Sb4 | November | Classroom 3 | 0 | 0 | 0 | 21.5 | 45 | - | - |
| OUT-Sb4 | November | Outdoor | - | - | - | 8.3 | 79 | 11.2 | 21.1 |
| OC-Sc1 | December | Classroom 6 | 25 | 0 | 330 | 25.2 | 40 | - | - |
| OUT-Sc1 | December | Outdoor | - | - | - | -0.1 | 48 | 11.2 | 0 |
| OC-Sc2 | December | Classroom 7 | 23 | 0 | 300 | 22.4 | 37 | - | - |
| OUT-Sc2 | December | Outdoor | - | - | - | 2 | 42 | 6.5 | 0 |
| UOC-Sc3 | December | Classroom 7 | 0 | 0 | 0 | 19.4 | 38 | - | - |
| OUT-Sc3 | December | Outdoor | - | - | - | -0.9 | 65 | 5.0 | 0 |
Sample type: Occupied classroom sample (OC); Unoccupied classroom sample (UOC); outdoor sample (OUT); Schools a, b, and c (Sa, Sb, and Sc); and different days (sequential number within the same school). Classroom ID (number in the column for the classroom/outdoor); Temperature (Temp); Relative Humidity (RH).