Where are evaporator pressure regulator (EPR) valves placed in a multiple temperature, multiple evaporator system?

In a multiple temperature, multiple evaporator system, evaporator pressure regulator (EPR) valves are strategically placed in the suction line of the warmer evaporator. This placement is crucial because the EPR valve helps to control the evaporator pressure within that specific evaporator, allowing it to operate efficiently by maintaining its desired low-pressure environment.

By regulating the pressure, the EPR ensures that refrigeration cycles do not over-cool the warmer evaporator. This is particularly important in systems with multiple evaporators operating at different temperatures, as it allows for balanced performance and prevents potential thermal overload or inefficiencies in the warmer sections of the system.

The other locations for the valves—such as the liquid line, condenser unit, or compressor discharge line—do not serve the same purpose as they either deal with different phases of refrigerant or the pressures associated with those components rather than optimizing the suction pressure in the specific evaporator.