Systems and methods are provided and include first and second case controllers for first and second refrigeration cases. The first case controller receives a first air temperature value of the first refrigeration case and communicates the first air temperature value to the second case controller. The second case controller receives a second air temperature value, determine an evaporator saturated suction temperature (SST) value, controls an evaporator pressure regulator based on a comparison of the evaporator SST value with an evaporator SST setpoint, determines an air temperature control value, determines whether the air temperature control value is within a predetermined range of an air temperature setpoint, and adjusts the evaporator SST setpoint in response to the air temperature control value being outside of the predetermined range of the air temperature setpoint.