In a face split coil arrangement of evaporators, which coil serves as the first stage of cooling?

In a face split coil arrangement of evaporators, the bottom coil serves as the first stage of cooling primarily due to the design and flow of refrigerant within the system. Typically, evaporators are arranged to utilize gravity and the natural convection of refrigerants effectively.

When refrigerant enters the system, it often is distributed to the bottom coil first. This design allows for a more efficient heat exchange process, as the cooler air, which is denser, will naturally flow downwards through the system. The bottom coil, therefore, takes advantage of this flow and maximizes its cooling capacity at the onset before the refrigerant is cycled to the upper and middle coils for further cooling stages.

Understanding the order in which these coils function is important for properly managing the cooling process, ensuring that the entire system operates effectively and is balanced. This arrangement allows for optimal energy efficiency and extends the lifespan of the cooling components.