In a DX or dry expansion coil evaporator, the refrigerant should leave in what state?

In a direct expansion (DX) coil evaporator, the refrigerant should leave in a superheated vapor state. This is because the primary function of the evaporator is to absorb heat from the environment, and as the refrigerant evaporates, it takes in heat, which transforms it from a liquid to a vapor.

Once the refrigerant has evaporated, it further absorbs heat and becomes superheated as it moves to the compressor. This ensures that only vapor enters the compressor, preventing liquid refrigerant from entering and potentially causing damage to the compressor, which could lead to inefficient operation or even failure.

The choice of a superheated vapor state at the exit of the evaporator is crucial for the effective and safe operation of the refrigeration system. It guarantees that the refrigeration cycle continues properly, allowing for efficient heat transfer and maintaining system performance.