Refrigeration efficiency is governed by the temperature regime and the whole cycle, not by compressor efficiency in isolation. Product load, suction pressure, condensing conditions, defrost and auxiliary power must be compared at equivalent cold service. Refrigerant global-warming potential is a separate environmental parameter: lowering GWP does not by itself prove final-energy savings. The relevant route among TER090, IND020, IND030, IND140, IND150, IND160, IND190, IND200, IND210 and IND220 must be chosen from the live catalogue.
Classify the refrigeration measure and service boundary
Describe whether the project replaces a condensing unit, compressor, cabinet, control strategy or complete central plant. Map cold rooms, display cases, process users and temperature levels. The many candidate codes address distinct configurations; they cannot be stacked merely because each name appears somewhere in the new system. Assign each code candidate to a specific asset change and refrigeration service before combining any calculations.
The baseline diagram should show compressors, evaporators, condensers, receivers, expansion devices, pumps and heat-rejection equipment. Record refrigerant charge and architecture, including direct expansion, secondary loops or transcritical stages. The diagram fixes which electrical auxiliaries and useful refrigeration loads sit inside the comparison. Keep a controlled baseline schematic because pipework changes can alter which auxiliaries and loads belong inside the boundary.
Characterise suction, condensing and product loads
Log suction and discharge pressures, evaporation and condensing temperatures, superheat, subcooling and compressor staging over representative load periods. A single design point misses floating head pressure, night covers, ambient effects and cycling. Product throughput and door-opening patterns help explain why two weeks consume differently. Align logger timestamps with production, ambient and door-event records so abnormal load periods can be explained.
Maintain equivalent room, cabinet or process temperatures and product loads. Reduced stock, shorter production or warmer setpoints lower electricity without demonstrating equipment efficiency. Normalisation should follow the sheet, and any bespoke adjustment needs transparent data rather than an unexplained ratio to sales. Product-temperature compliance and throughput should accompany energy trends to demonstrate equivalent refrigeration service.
Separate GWP choices from energy calculations
GWP or PRG expresses climate impact per mass of released refrigerant; it is not an energy-efficiency ratio. A low-GWP fluid may improve or worsen cycle performance depending on equipment and regime. Record environmental compliance separately, then calculate eligible final-energy savings with the variables authorised by the selected method. Performance-map inputs must use consistent saturated-temperature conventions and the refrigerant actually charged.
Compare compressor performance maps at relevant saturated temperatures and part load. Include condenser fans, evaporator fans, pumps, crankcase heaters and defrost where the boundary requires them. Pressure optimisation or economiser effects should not be added twice to the efficiency of a newly selected compressor. Net savings should include auxiliary and control effects whenever the selected sheet places them inside the system boundary.
Instrument commissioning across operating regimes
Commission controls through pull-down, stable load, low ambient, defrost and fault conditions. Trend compressor stages, valve positions, temperatures and electrical demand at synchronized timestamps. These traces can show whether a floating setpoint is active or merely described in the control narrative. Witness tests should span pull-down, steady operation and defrost rather than relying on one favourable operating point.
Keep refrigerant transfer records, leak checks, plate photographs, component models, settings, invoices and the as-built schematic. Link removed and installed assets to the same refrigeration service. Where a central plant serves many users, identify meters or allocation rules rather than relying on one total utility bill. Reconcile refrigerant and component records with asset tags so the as-built cycle can be reproduced from the evidence pack.
Avoid overlap among compressor, control and central-plant claims
Watch for oil-return problems, excessive discharge temperature, wet suction and control hunting after conversion. Food safety and process quality remain constraints. A lower-energy month caused by poor pull-down or disabled anti-sweat heaters is not acceptable evidence of equivalent refrigeration performance. Investigate control instability and disabled anti-sweat loads before accepting a reduction in measured electricity.
Use the current PDF, annexes and transitional rules to settle formula and evidence questions; this broad code list is not an eligibility conclusion. Present savings before verification as provisional and stress-test the commercial case for lower recognition. Refrigerant compliance and CAE validation follow different tests. The reference codes for this review are TER090, IND020, IND030, IND140, IND150, IND160, IND190, IND200, IND210 and IND220. Model a less favourable load or condensing regime when testing whether the investment survives verification uncertainty.