Where does the Thermal Expansion Valve (TXV) function in relation to the evaporator?

The Thermal Expansion Valve (TXV) functions upstream of the evaporator in a refrigeration or air conditioning system. Its primary role is to regulate the flow of refrigerant into the evaporator coil based on the cooling demand and the temperature of the refrigerant vapor returning from the evaporator.

By being positioned upstream, the TXV can accurately control how much refrigerant is allowed to enter the evaporator. This regulation is crucial because the evaporator needs a specific amount of refrigerant to absorb heat effectively, ensuring that the cooling process is efficient and that the system functions optimally. If the TXV were located downstream or in a different position relative to the evaporator, it would not be able to effectively manage the flow of refrigerant, potentially leading to improper system performance, inefficient cooling, or even damage to the components.