water chiller units is a kind of open type chiller. Open-type chillers are mainly composed of compressors, evaporators, condensers, electric control systems, and refrigeration accessories. Water-cooled box-type chillers are composed of compressors, evaporators, condensers, water pumps, water tanks, electric control systems, and refrigeration accessories. Therefore, it can be seen that the difference between the two is that the water-cooled box-type chiller can have a built-in water pump and water tank, and vice versa, it is called an open-type chiller.