There are many household types of refrigerators, which are generally classified according to their internal cooling, purpose, climate, appearance, and placement and cooling methods. Refrigerator cooling classification: Forced circulation of cold air: also known as intercooled (air-cooled) or frost free refrigerators. There is a small fan in the refrigerator that forces the air inside the box to flow, so the temperature inside the box is uniform, the cooling speed is fast, and the use is convenient.There are many household types of refrigerators, which are generally classified according to their internal cooling, purpose, climate, appearance, and placement and cooling methods. Refrigerator cooling classification: Forced circulation of cold air: also known as intercooled (air-cooled) or frost free refrigerators. There is a small fan in the refrigerator that forces the air inside the box to flow, so the temperature inside the box is uniform, the cooling speed is fast, and the use is convenient.