Chiller Commissioning Checklist

What chiller commissioning involves

Commissioning a chiller is the work of verifying that the unit and its supporting components are correctly installed, configured and operating before the system is released into service. It runs from pre-startup checks through to steady-state operation, and covers the chiller itself as well as auxiliary components such as electric motors, valves, sensors and accessories. This checklist gives you a single record of that work, organised into pre-startup verification, post-startup assessment, and the operational parameters and readings taken across both stages.

Why commissioning matters

A chiller that starts up without verification can carry installation faults, incorrect settings or contamination into normal operation. The checklist builds the checks into the start-up sequence so they are not skipped under schedule pressure: functionally testing safety devices and emergency controls, confirming safety valve opening pressures, running a vacuum test for system integrity, and performing leak detection across the entire refrigerant circuit. It also keeps a traceable record. A start-up log is completed at full load, an oil sample is collected after roughly one hour of operation and retained for at least a year, and the record is signed off with dates, so the baselines captured here stay available for later comparison.

What the checklist covers

The checklist contains 50 items across four areas. **Pre-startup verification.** Review the equipment manuals, including the chiller unit, control systems and related documentation, and the manuals for all auxiliary components. Confirm proper unit installation and vibration damper configuration, functionally test all safety devices and emergency controls, verify safety valve opening pressures, conduct a vacuum test, configure the controller and VSD where applicable, check the oil level, and confirm the oil sump heater has been energised for a minimum of 6-8 hours before initial start-up. Extract and verify a primary refrigerant sample is free from moisture, air and contaminants, check motor rotation direction, confirm coupling alignment to manufacturer specifications, verify the compressor cooling system, perform leak detection, and confirm all system valves are positioned correctly for the operational mode. **Post-startup assessment.** Confirm the capacity regulation system operates correctly across the full load range, verify the refrigerant charge is adequate under full load, complete a detailed start-up log at full load, and collect a representative lubricating oil sample after about one hour of operation for retention for at least a year. Inspect for abnormal vibrations at steady state and evaluate vibration levels across the variable speed operating range. **Operational parameters and readings.** Record suction pressure and temperature, superheating of the suction gas, discharge pressure and temperature, compressor and filter oil pressure, oil temperature, separator oil temperature, oil collection from the shaft seal, oil level in litres where charged, motor full load current, capacity load percentage, noise level, vibration from 0-100% capacity, brine outlet temperature at the evaporator and condenser, and refrigerant charge in kilograms. **Documentation.** Capture the date, who prepared the checklist, the location, and the equipment model and serial number, then close out with additional observations and commissioning notes, a signature, and the inspection start and end dates.

How to carry out the commissioning

1. Complete the title section so the record is tied to a specific unit and date. 2. Work through pre-startup verification before the first start. Where a step has a defined precondition, such as energising the oil sump heater for a minimum of 6-8 hours, allow the time rather than compressing it. 3. Verify the mechanical and electrical setup: rotation direction, coupling alignment against manufacturer specifications, and the compressor cooling system. 4. Prove integrity and containment: the vacuum test, the refrigerant sample check, and leak detection across the complete refrigerant circuit. 5. Start the unit and move to post-startup assessment. Check capacity regulation across the full load range, confirm refrigerant charge under full load, and evaluate vibration both at steady state and across the variable speed range. 6. Take the readings while the unit is running, using the unit specified for each value so the measurements stay comparable. 7. Collect the oil sample after about one hour of operation and retain it for at least a year from the commissioning date. 8. Complete the start-up log at full load, add observations and notes, and record the inspection start and end dates alongside a signature.

Frequently asked questions

**What does the chiller commissioning checklist cover?** It contains 50 items across a title section, pre-startup verification, post-startup assessment, and operational parameters and readings. Pre-startup items include reviewing equipment and auxiliary component manuals, confirming installation and vibration damper configuration, functionally testing safety devices and emergency controls, checking safety valve opening pressures, a vacuum test, controller and VSD configuration, oil level, energising the oil sump heater for at least 6-8 hours, verifying a primary refrigerant sample is free from moisture, air and contaminants, motor rotation direction, coupling alignment, the compressor cooling system, and leak detection across the refrigerant circuit. Post-startup items cover valve positioning, capacity regulation across the full load range, refrigerant charge under full load, vibration inspection and evaluation across the variable speed range, and a start-up log at full load. The readings section captures suction, discharge, oil and brine temperatures, plus pressures, oil volumes and levels, motor current, capacity load, noise and vibration, and refrigerant charge. **What should you verify before first start-up?** Review the manuals for the chiller unit, control systems and related documentation, and for auxiliary components such as electric motors, valves, sensors and accessories. Then verify installation and vibration damper configuration, functionally test all safety devices and emergency controls, confirm safety valve opening pressures, run a vacuum test for system integrity, check oil level, and energise the oil sump heater for a minimum of 6-8 hours. Extracting and verifying a primary refrigerant sample is free from moisture, air and contaminants, confirming motor rotation direction, and checking coupling alignment against manufacturer specifications all belong in the pre-startup stage. **What readings should you record during chiller commissioning?** Suction, discharge, oil and brine temperatures, alongside pressures, oil volumes, motor current and refrigerant charge. Specifically: suction pressure and temperature, superheating of the suction gas, discharge pressure and temperature, compressor and filter oil pressure, oil temperature, separator oil temperature, oil collection from the shaft seal, oil level, charged oil volume in litres, motor full load current, capacity load percentage, refrigerant charge in kilograms, and brine outlet temperature at both the evaporator and the condenser. These are backed by assessments of noise level and vibration from 0-100% capacity, plus notes, a signature and start and finish times. **How do you use the chiller commissioning checklist?** Use it to document observations consistently at both the pre-startup and post-startup stage. It supports recording and monitoring suction, discharge, oil and brine temperatures, keeping oversight of daily chiller operations through the commissioning process, and managing operational risk. A completed record includes a start-up log at full load, an oil sample collected after about one hour of operation and retained for at least a year from the commissioning date, plus a signature and the inspection start and end dates.

Frequently Asked Questions

The checklist covers 50 items across four areas: a title section for recording the date, preparer, location and equipment model and serial number; pre-startup verification; post-startup assessment; and operational parameters and readings. Pre-startup items include reviewing equipment and auxiliary component manuals, confirming installation and vibration damper configuration, functional testing of safety devices and emergency controls, checking safety valve opening pressures, a vacuum test for system integrity, controller and VSD configuration, oil level, energising the oil sump heater for a minimum of 6-8 hours before initial start-up, verifying a primary refrigerant sample is free from moisture, air and contaminants, motor rotation direction, coupling alignment, compressor cooling system configuration and a leak detection test across the refrigerant circuit. Post-startup items cover valve positioning, capacity regulation across the full load range, refrigerant charge under full load, vibration inspection and evaluation across the variable speed range, and a start-up log at full load. The readings section captures suction, discharge, oil and brine temperatures, plus pressures, oil volumes and levels, motor current, capacity load, noise and vibration, and refrigerant charge.

Commissioning checks the chiller and its auxiliary components as an integrated system before and after start-up. Key preparation steps include reviewing the manuals for the chiller unit, control systems and related documentation, and for auxiliary components such as electric motors, valves, sensors and accessories. Before first start-up, verify installation and vibration damper configuration, functionally test all safety devices and emergency controls, confirm safety valve opening pressures, run a vacuum test for system integrity, check oil level, and energise the oil sump heater for a minimum of 6-8 hours. Extracting and verifying that a primary refrigerant sample is free from moisture, air and contaminants, confirming motor rotation direction, and checking coupling alignment against manufacturer specifications all belong in the pre-startup stage.

Include suction, discharge, oil and brine temperature readings, alongside pressures, oil volumes, motor current and refrigerant charge. The checklist captures suction pressure and temperature, superheating of the suction gas, discharge pressure and temperature, compressor and filter oil pressure, oil temperature, separator oil temperature, oil collection from the shaft seal, oil level, charged oil volume in litres, motor full load current, capacity load percentage, refrigerant charge in kilograms, and brine outlet temperature at both the evaporator and the condenser. Readings are backed by assessments of noise level and vibration between 0 and 100 percent capacity, plus notes, a signature and start and finish times.

Use it to document observations consistently at both the pre-startup and post-startup stage. It supports recording and monitoring suction, discharge, oil and brine temperatures, keeping oversight of daily chiller operations through the commissioning process, and managing operational risk. A completed record includes a start-up log at full load, an oil sample collected after approximately one hour of operation and retained for a minimum of one year from the commissioning date, plus a signature and the inspection start and end dates.

Written by

Arne Reis

Founder

Process optimizer with 25 years of expertise, focused on operational excellence in quality, maintenance, EHS, and commissioning. Emphasizes innovative solutions and top-quality standards.

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