Heat transfer devices are tools designed to move heat from one location to another. Common examples include radiators, heat exchangers, and air conditioners. These devices utilize various methods, such as conduction, convection, and radiation, to efficiently transfer thermal energy, ensuring comfortable temperatures in buildings and effective operation in industrial processes. In many applications, heat transfer devices play a crucial role in energy efficiency. For instance, heat pumps can both heat and cool spaces by transferring heat in or out, depending on the season. Understanding how these devices work helps improve energy use and reduce costs in residential and commercial settings.