The study's findings underscore the critical importance of sensor placement in IAQ monitoring. Although useful for long-term installations, wall-mounted sensors may not provide real-time sensitivity in environments with rapidly changing air quality. The wall-mounted sensor shows both concentration differences and time delay regarding the particle concentrations. All measurements show more than a 30% discrepancy between the peaks of the wall sensor maximum numbers and the maximum numbers of the two other sensors, except for Point 2 measurement, where the point source is near the center of the room.