A device with a large surface area designed to heat the air near it by conduction is called a radiator.

Here's why:

* Large surface area: Radiators are designed with fins or other extended surfaces to maximize the area in contact with the air. This increases the rate of heat transfer.

* Conduction: Heat is transferred from the hot radiator surface to the cooler air molecules in direct contact with it. This is the process of conduction.

Examples of radiators include:

* Heating radiators: Used in homes and buildings to heat the air in a room.

* Engine radiators: Used in vehicles to cool the engine by transferring heat from the engine coolant to the air.

Let me know if you have any more questions!