This accademic work describes the air-conditioning system of the ship's dwellings, that is, the principle of operation and the devices used to obtain easy conditions for staying in the ship's dwellings. Air conditioning is the process of preparing the air for the purpose of obtaining as much comfort as possible for people to stay indoors. The first part of the paper deals with the air conditioning unit and the compressor refrigeration unit, where the parts and principle of operation of the unit are generally indicated. Also, schematics of the device are presented where the operating principle and cooling cycle are explained in more detail. In the central part of the work touches the control and protection devices, which are thermostats and pressure switches. It is a question of ventilation for the supply and exchange of air in ship's premises, which can be natural and artificial. Filtration removes impurities and gases from the air, so the effects of filtration and filter materials are discussed. The last section discusses the elements necessary for air distribution and the determination of the amount of air for air conditioning where the recommended amounts of air per person, the maximum amount of pollutants in the air, and the number of air changes required per hour.