Most classrooms in our school suffer from low ventilation due to a lack of windows, poor ventilation designs, or malfunctioning fans. In the afternoons, especially after lunchtime, classrooms tend to be hot and crowded, affecting the comfort levels of 40-60 students per classroom., Due to low oxygen levels and hot temperatures, students feel sleepy, cannot focus, and feel uncomfortable. The teachers also face difficulties in keeping their concentration levels under control., The problem is faced on a day-to-day basis.