Ships play a major role in the development of world trade and tourism. In addition to maintaining the temperature of various foods in everyday transport, refrigeration or air conditioning systems are used to create a feeling of comfort, during the voyage, for passengers and crew. Main components are such as condenser, compressor, evaporator, damping element and refrigerant. Refrigerants have varied throughout history, and their selection was based on environmental impact. The first CFCs were, from a thermophysical point of view, the best refrigeration solution, but they have proven to have a major negative impact on the ozone layer. Therefore today, we strive to find their economically and environmentally acceptable substitutes. In addition to cooling and heating, an important part of this system is ventilation. It can be natural or forced, which is used to improve the cooling performance. Basically, the system is based on the transfer of thermal energy from a substance of higher temperature to a substance of lower temperature, so each part of the ship's cooling device and their roles is processed.