Finned tube is a type of heat exchanger used in heating and cooling systems, using fins (small sheets) to increase the surface area of the pipe and improve its heat transfer capacity. Finned tubes work by forming a thin film of water on the pipe, which evaporates as heat is transferred from the system to the fin, thereby increasing the heat dissipation effect.

Finned tubes are commonly used in air heating and cooling systems such as heating, air conditioning and refrigeration equipment. They are also used in industrial applications, such as power plants and chemical plants, to transfer heat efficiently.

The specific way finned tubes work depends on their use in the system. In heating systems, finned tubes are usually filled with hot water or steam, and the heat is transferred through the fins to the surrounding air. In cooling systems, finned tubes are usually filled with cold water or refrigerant, and heat is transferred from the surrounding air to the fins and pipes.

In general, finned tubes increase the heat transfer efficiency by increasing the surface area of the pipe and utilizing the evaporation of the water film, and are an important component in many different types of heating and cooling systems.