Finned tube radiators used as heating elements are designed to efficiently transfer heat from a fluid (often steam or hot water) flowing through the tubes to the surrounding air. Here's how they typically work:

1. **Tube Construction**: The core of the radiator consists of a series of interconnected tubes through which the heating fluid flows. These tubes are often made of materials like copper, steel, or stainless steel, chosen for their heat conductivity and durability.

2. **Fins**: Fins are attached to the outer surface of these tubes. They are usually made of aluminum or steel and are designed to increase the surface area available for heat transfer. This allows more efficient transfer of heat from the tubes to the surrounding air.

3. **Heat Transfer**: When hot fluid (steam or hot water) flows through the tubes, it heats up the tubes and the fins attached to them. The fins then transfer this heat to the air passing over them, either by natural convection (air movement caused by temperature differences) or forced convection (using fans or blowers).

4. **Applications**: Finned tube radiators are widely used in heating systems for buildings, industrial processes, and even in transportation (like locomotives and ships). They are chosen for their efficiency in transferring heat and their ability to withstand high temperatures and harsh environments.

5. **Design Considerations**: The design of finned tube radiators takes into account factors such as the heat output required, the temperature of the heating fluid, the airflow conditions, and space constraints. Different fin designs (such as plain, perforated, or louvered) can be used to optimize heat transfer performance based on specific application requirements.

Overall, finned tube radiators are a versatile and efficient choice for heating applications where effective heat transfer to the surrounding air is essential.