A radiator is a type of heat exchanger that is used to transfer thermal energy from one medium to another. It is commonly used in heating, ventilation, and air conditioning (HVAC) systems to regulate the temperature of a room or building. Radiators are typically made of metal, such as aluminum or copper, and can be either liquid- or air-cooled. Liquid-cooled radiators use a coolant, such as water or antifreeze, to absorb and transfer heat away from the radiator, while air-cooled radiators use air to dissipate the heat. Radiators can also be used to cool engines in automobiles, as well as other machinery. In addition to their use in HVAC systems, radiators are also used in industrial processes, such as oil refining and chemical processing, to help regulate the temperature of a given system. Radiators are an essential component of any HVAC system, as they are responsible for controlling the temperature of a room or building. Without a properly functioning radiator, a room or building can become too hot or too cold, leading to uncomfortable living and working conditions.