Introduction to Chiller Qualification
Chiller Qualification-A chilled water system can be an important utility in a pharmaceutical manufacturing facility. Chilled water may be used for cooling HVAC systems, process equipment, manufacturing areas, heat exchangers and other temperature-control applications. Because the performance of the chiller can affect critical facility and process conditions, the system should be appropriately qualified before routine use and periodically reassessed according to the site’s qualification program.
Water-Cooled Screw Chiller Qualification generally involves documented verification that the installed system is correctly installed, operates as intended, and can consistently deliver the required performance under defined operating conditions.
What Is a Water-Cooled Screw Chiller ?
A water-cooled screw chiller is a refrigeration system designed to remove heat from a circulating chilled-water loop. In a typical arrangement, water passes through the evaporator, where heat is transferred from the water to the refrigerant. The refrigerant is then compressed, condensed and expanded as part of the refrigeration cycle before returning to the evaporator.
A screw chiller generally uses a rotary screw compressor together with heat exchangers, refrigerant controls, oil-management components, sensors and a control system.
For related pharmaceutical qualification procedures, read our detailed guides on [AHU Qualification], [Water System Qualification], and [Compressed Air Qualification] to understand the qualification of critical HVAC, utility, and compressed-air systems.
Why Is Chiller Qualification Required?
Qualification provides documented evidence that a newly installed or modified utility is suitable for its intended application.
For a pharmaceutical facility, qualification can help demonstrate that:
- The chiller has been installed according to approved design information.
- Major components are present and correctly connected.
- Electrical and utility connections are appropriate.
- Safety devices and interlocks function as intended.
- Instruments used for monitoring and verification are suitable and calibrated.
- The control system provides the required operating information.
- Chilled-water temperatures and other important operating parameters can be monitored
IQ, OQ and PQ Qualification
The qualification stages have different purposes.
| Stage | Purpose |
| Installation Qualification (IQ) | To verify that the chiller and associated components have been installed according to approved specifications, drawings and requirements. |
| Operational Qualification (OQ) | To verify that controls, functions, alarms, interlocks and operating features work as intended. |
| Performance Qualification (PQ) | To demonstrate that the system can deliver the required performance under defined operating conditions. |
Responsibilities During Qualification
| Department | Responsibility |
| Engineering | Installation verification, technical checks, execution of qualification tests and recording of technical observations. Review of equipment condition, maintenance-related information and technical documentation |
| Production/User Department | Confirmation that the utility is suitable for its intended operational application |
| Quality Assurance | Protocol review/approval, witnessing of applicable tests, review of deviations and final qualification assessment. Coordination of qualification activities and compilation of the qualification report |
Chiller System Description
The source document describes a water-cooled screw chiller equipped with a compressor, evaporator, condenser, control system, starter panel and oil-management components.
Compressor and Motor
The described compressor is a semi-hermetic, direct-drive helical rotary type. The system includes capacity control, an oil sump heater and an oil-management arrangement. The compressor motor is described as a suction-gas-cooled, hermetically sealed induction motor.
Evaporator and Condenser
The evaporator and condenser are described as shell-and-tube heat exchangers. The refrigeration cycle transfers heat from the chilled-water circuit through the evaporator and rejects that heat through the condenser using condenser water.
The source document identifies copper tubes and water-side connections as part of the equipment specification.
Control System
The chiller uses a microprocessor-based control system. The control system monitors operating conditions and provides protective functions for abnormal conditions such as excessive refrigerant temperature or pressure, inadequate oil flow, motor overload and water-flow problems.
HMI and Display
The operator interface provides access to operating information, reports, settings, service functions and diagnostic information.
During OQ, the HMI should be checked against the approved equipment specification or manufacturer’s documentation to confirm that the required information, controls and alarms are available.
Oil Management
The source describes an oil separator, oil filter and oil cooler. These components support compressor lubrication and help maintain appropriate oil circulation and operating conditions.
Chilled-Water and Condenser-Water Circuit
A water-cooled chiller normally depends on two water circuits:
- Chilled-water circuit
- Condenser-water circuit
The chilled-water circuit carries cooled water from the chiller to the user equipment or HVAC system and returns warmer water to the chiller.
The condenser-water circuit removes heat from the condenser and normally rejects it through the associated cooling-water system.
Example Equipment Data From the Source
The supplied document contains equipment-specific values such as:
| Parameter | Source document value |
| Chiller capacity | 300 TR |
| Chilled-water inlet temperature | 12°C |
| Chilled-water outlet temperature | 6°C |
| Condenser-water inlet temperature | 32°C |
| Condenser-water outlet temperature | 36°C |
| Electrical supply | 415 V, 3 phase, 50 Hz |
| Refrigerant | R-134a |
| Chilled-water pump arrangement | 2 working + 1 standby |
| Condenser-water pump arrangement | 2 working + 1 standby |
Installation Qualification of Water-Cooled Screw Chiller- Chiller Qualification
Installation Qualification verifies that the equipment and its supporting systems have been installed as specified.
The source protocol includes checks for equipment position, accessibility, physical condition, leveling, wiring, identification, cleaning, safety labels and technical specifications.
1. Verify Equipment Location
Check that the chiller is installed at the approved location and matches the applicable drawing or layout.
Verify:
- Equipment location
- Orientation
- Accessibility
- Service clearance
- Relationship with connected utilities
- Maintenance access
Adequate clearance should be available for routine operation, inspection and maintenance.
2. Inspect Physical Condition
Carry out a visual inspection of the equipment.
Check for:
- Physical damage
- Missing components
- Damaged insulation
- Damaged piping
- Damaged electrical enclosures
- Loose fittings
- Abnormal corrosion
- Damaged gauges or instruments
Any abnormality should be documented and assessed before proceeding.
3. Verify Leveling and Installation
The source protocol includes checking the equipment level using a spirit level.
The installation should be verified against approved drawings and equipment requirements rather than relying solely on a generic criterion.
4. Verify Electrical Connections
Electrical connections should be checked against the approved electrical drawings.
Verify:
- Incoming power supply
- Electrical panel
- Motor connections
- Earthing
- Cable routing
- Protective devices
- Control wiring
- Phase arrangement where applicable
5. Verify Equipment Identification
The equipment identification number should be available and consistent with the approved equipment documentation.
Identification should be traceable to the qualification documents, drawings, SOPs and maintenance records.
6. Verify Initial Cleaning
Before qualification, the equipment should be clean and free from construction debris, foreign material and other visible contamination.
Technical Specification Verification
Technical specifications should be compared against approved equipment documents.
The source document includes checks for:
- Overall equipment dimensions
- Required clearance
- Cooling capacity
- Refrigerant
- Voltage and frequency
- Flow rates
- Anti-vibration arrangement
- Noise level
- Compressor construction
- Evaporator design
- Condenser design
- Motor and starter information
Examples from the supplied document include a 300 TR chiller, 415 V/50 Hz electrical supply, R-134a refrigerant and defined chilled- and condenser-water design temperatures.
Important qualification principle
The specification table should be compared against the approved URS, purchase specification, approved drawing and manufacturer’s documentation.
Utility Verification
A chiller depends on supporting utilities for safe and reliable operation.
Typical checks include:
- Electrical power
- Chilled-water connections
- Condenser-water connections
- Water-flow availability
- Control signals
- Drainage where applicable
- Instrumentation
- Earthing
The source document specifies a three-phase 415 V, 50 Hz supply and includes water-connection verification.
Safety Feature Verification
Safety features should be verified during qualification.
The supplied protocol includes checks for:
- Motor protection
- Electrical cables
- Earthing
- Pressure relief arrangements
- Safety labeling
- Protective devices
Why Safety Interlocks Matter
A chiller should not be allowed to operate under conditions that could damage the equipment or create an unsafe situation.
Examples include:
- Insufficient water flow
- Excessive refrigerant pressure
- Motor overload
- Loss of phase
- Critical sensor failure
- Emergency-stop activation
Operational Qualification of the Chiller-Chiller Qualification
Operational Qualification verifies that the chiller operates according to its intended functional requirements.
The source protocol includes testing of the isolator, HMI, display screens, reports, settings, water-level interlock and operating parameters.
HMI and Control Verification
A practical OQ should verify applicable functions such as:
- Start command.
- Stop command.
- Auto operation.
- Display of operating parameters.
- Alarm indication.
- Diagnostic messages.
- Access to reports.
- Set-point adjustment where authorized.
- Date and time.
- User/security controls where applicable.
The exact functions depend on the installed controller and approved equipment specification.
Main Operating Screen
The supplied document identifies information such as:
- Chilled-water set point
- Motor current
- Entering and leaving chilled-water temperature
- Entering and leaving condenser-water temperature
- Frequency command
- Evaporator water-flow status
- Condenser-water-flow status
These parameters can be useful during qualification because they provide evidence that the control system is receiving and displaying relevant process information.
Report and Settings Screens
The source document also identifies report functions covering areas such as:
- Evaporator
- Condenser
- Compressor
- Motor
- Operating modes
- Log information
The settings area includes functions such as chiller settings, chilled-water reset, display preferences, language, date/time and security.
Interlock Verification
Interlocks should be tested using an approved and controlled test method.
The supplied protocol provides an example involving inadequate water level and verifies that the utility should not start under the specified unsafe condition. After restoration of the required water condition, the utility should be capable of starting.
Other applicable interlocks may include:
- Water-flow interlock
- High-pressure protection
- Low-pressure protection
- Motor overload
- Emergency stop
- Phase protection
- Sensor failure
- Low-temperature protection
Technical Parameter Verification
During OQ/PQ, important chiller parameters should be monitored and recorded.
Evaporator-side parameters
- Water-flow status
- Entering-water temperature
- Leaving-water temperature
- Pressure drop
Condenser-side parameters
- Water-flow status
- Entering-water temperature
- Leaving-water temperature
- Refrigerant temperature where applicable
- Pressure drop
Performance Qualification of the Chiller
Performance Qualification should demonstrate that the chiller can provide the required performance under predefined operating conditions.
The source document evaluates performance by monitoring chilled-water temperature at the chiller return line while testing selected temperature settings.
General PQ Approach
A practical sequence can be:
- Confirm completion and approval of IQ/OQ activities.
- Confirm required utilities are available.
- Confirm instruments are calibrated.
- Start the chiller according to the approved operating procedure.
- Allow the system to stabilize.
- Establish the predefined operating condition.
- Record the relevant temperatures and operating parameters.
- Repeat the test at the predefined set points or operating conditions.
- Compare the results with the approved acceptance criteria.
- Document deviations, if any.
- Evaluate the overall results and prepare the qualification report.
Example of Temperature Verification The supplied protocol uses selected chiller set points and specifies a tolerance of ±0.5°C around the set value for the water-temperature check. However, this should not automatically be treated as a universal GMP requirement.
Example of PQ – Chiller Qualification
| Test condition | Parameter monitored | Acceptance criterion | Observation |
| Defined set point 1 | Chilled-water temperature | As per approved protocol | Record actual value |
| Defined set point 2 | Chilled-water temperature | As per approved protocol | Record actual value |
| Defined set point 3 | Chilled-water temperature | As per approved protocol | Record actual value |
| Defined operating load | Flow/temperature/other critical parameters | As per approved protocol | Record actual value |
Acceptance Criteria for Chiller Qualification
Acceptance criteria should be established before execution and should be based on approved technical and operational requirements.
Possible qualification criteria include:
Installation
- Equipment installed at the approved location.
- Major components are present.
- Equipment identification is available.
- Connections correspond to approved drawings.
- Electrical installation is satisfactory.
- Required safety labels are present.
- Required service access is available.
Operation
- Start and stop functions work correctly.
- HMI displays the required information.
- Relevant alarms and interlocks function as intended.
- Operating parameters are displayed or recorded correctly.
- Protective functions operate according to approved control logic.
Performance
- Chilled-water temperature meets the approved requirement.
- Required flow is available.
- Relevant operating parameters remain within predefined limits.
- The system demonstrates stable operation during the defined test.
Common Mistakes During Chiller Qualification
Several problems can weaken a qualification exercise.
1. Using Generic Acceptance Criteria
A common mistake is to use the same temperature, pressure or flow limit for every chiller.
Better approach: establish criteria from the approved URS, equipment specification, design and intended application.
2. Leaving Manufacturer and Model Information Blank
The supplied protocol contains several fields showing “-” for manufacturer or model information. Such fields should be completed from approved equipment documentation before final protocol approval.
3. Copying Old Protocols Without Technical Review
Previous protocols can be useful templates, but every new qualification document should be checked against the actual equipment.
4. Incomplete Calibration Verification
A qualification result is difficult to defend if the measuring instrument’s calibration status is not demonstrated.
Documentation and Records
A complete qualification package may include:
- Approved qualification protocol
- URS
- Design documents
- Equipment specification
- Purchase documentation
- Manufacturer manuals
- Approved drawings
- Electrical drawings
- Piping drawings
- Installation records
- Calibration certificates
- IQ results
- OQ results
- PQ results
- Alarm/interlock test records
- Deviations
- Change controls
- Supporting certificates
- Final qualification report
- Approved SOP for operation
Requalification of the Chiller
Requalification should be considered according to the site’s approved qualification program and risk assessment.
The supplied protocol identifies the following situations:
- Installation of a new system
- Major modification
- Change of location
- Periodic requalification
- Other defined circumstances requiring qualification
Example Chiller Qualification Checklist
| Area | Verification |
| Installation | Location and installation verified |
| Equipment condition | No unacceptable physical damage |
| Identification | Equipment ID verified |
| Drawings | Installation compared with approved drawings |
| Electrical | Power supply and connections verified |
| Earthing | Earthing verified |
| Piping | Connections and flow direction verified |
| Insulation | Insulation condition verified |
| Instruments | Calibration status verified |
| Safety | Safety devices and labels verified |
| HMI | Display and control functions verified |
| Alarms | Applicable alarms verified |
| Interlocks | Applicable interlocks challenged |
| Chilled water | Temperature and flow monitored |
| Condenser water | Temperature and flow monitored |
| Performance | Defined operating conditions evaluated |
| Documentation | Results recorded and reviewed |
| Deviations | Deviations investigated where applicable |
| Final assessment | Qualification report approved |
Practical Chiller Qualification Flow
A simple way to understand the complete activity is:
URS / Design Requirements
↓
Equipment Procurement & Installation
↓
Installation Verification (IQ)
↓
Operational Testing (OQ)
↓
Performance Testing (PQ)
↓
Deviation Assessment, if applicable
↓
Qualification Report
↓
QA Approval
↓
Routine Operation
FAQs for Chiller Qualification
1. What is chiller qualification in pharmaceuticals?
Chiller qualification is a documented process used to verify that a pharmaceutical chiller has been installed correctly, operates as intended and can consistently provide the required performance under predefined conditions.
2. What are IQ, OQ and PQ for a chiller?
IQ verifies installation, OQ verifies operational functions such as controls, alarms and interlocks, and PQ verifies that the chiller can deliver the required performance during defined operating conditions.
3. Is chiller qualification required for GMP facilities?
Where a chiller is a utility that can affect GMP-relevant facility or process conditions, its qualification should be addressed through the site’s qualification and risk-management program.
4. What parameters should be checked during chiller qualification?
Depending on the system, parameters may include chilled-water temperature, condenser-water temperature, water flow, pressure, electrical parameters, alarms, interlocks and relevant control-system indications.