Ceiling-mounted air conditioning units are composed of mixed air section, filtration section, cooling section, humidification section, and fan section. They are formed by the evaporation of chilled water through an evaporator and the heat exchange conversion by the fan. They feature a compact structure, small size, and are suitable for installation in ceilings with suspended mounting to minimize installation space. They offer various supply and return air options, including the introduction of fresh air, which effectively improves air quality. They are equipped with independent cold bridge prevention and sealing measures. They have multiple protection features. With microcomputer control, self-diagnosis of faults, and options for wired and remote control, installation methods are flexible and maintenance is convenient.