Air-quality detection apparatus

An air-quality detection apparatus, comprising:

• a casing body comprising a bottom and a side wall extending upwards from a circumference of the bottom;
• a first printed circuit board (PCB) disposed horizontally above the bottom;
• a second PCB disposed horizontally in a first region above the first PCB;
• a CO2 sensor mounted on the second PCB;
• a volatile organic compound (VOC) sensor mounted in a second region on a top surface of the first PCB, the second region being closer to the side wall than the first region;
• a third PCB on which a wireless communication interface is mounted, the third PCB being disposed horizontally at a position spaced further upwards apart from the bottom than the first PCB, at least a portion of the third PCB being disposed in a third region that does not overlap the first PCB when the bottom is viewed from above;
• a fourth PCB disposed horizontally above the second PCB and the third PCB;
• and
• a dust sensor mounted on a top surface of the fourth PCB.