A four-side courtyard evaporator is a type of air-cooled heat exchanger that is commonly used in commercial refrigeration and air conditioning systems. It consists of a rectangular-shaped enclosure that is open on all four sides, with a series of refrigerant tubes and fins located inside the enclosure.

In a four-side courtyard evaporator, the refrigerant flows through the tubes while the enclosure is exposed to the surrounding air. As air flows through the enclosure, it comes into contact with the fins on the refrigerant tubes, which transfer heat from the refrigerant to the air. The heated air then exits the enclosure, while the cooled refrigerant continues on to the next stage of the refrigeration system.

One advantage of a four-side courtyard evaporator is that it provides a large surface area for heat transfer, which can result in high efficiency and fast cooling. Additionally, because the enclosure is open on all four sides, air can circulate freely through the unit, which can help to prevent hot spots and improve cooling performance.