This measure applies to multiplex refrigeration systems (i.e., compressors operating in parallel) only.
The measure unit is evaporator design load in MBH.
Implementation requires use of the BPA Refrigeration Controls Calculator, and the MBH in the submitted calculator must match the highlighted or circled MBH in the submitted refrigeration schedule. The end-user can apply for either the Floating Head Pressure Control Measure, the Floating Suction Pressure Control Measure, or both, as indicated in the calculator.
Floating Head Pressure Control:
Pre-condition – The minimum head pressure temperature set point must be fixed and have exceeded or been equal to 80 degrees Fahrenheit.
Post–condition – Minimum head pressure control set point must be 70 degrees Fahrenheit.
Floating Suction Pressure Control:
Pre–condition – The base case must be a fixed suction pressure or temperature set point, as noted in the calculator.
Post–condition – post-project suction pressure shall be enabled to float, as indicated in the BPA Refrigeration Controls Calculator, based on input from a temperature sensor in a critical case on the appropriate suction group.