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Contributor
• Particle counts : A crucial aspect of HVAC validation is monitoring particle counts within the clean room . These counts are carefully analysed to ensure that the clean room environment meets specified standards .
• Air flow visualisation : Visualising air flow patterns within the clean room is essential . It helps identify areas of turbulence or stagnation , allowing for necessary adjustments to ensure uniform air distribution .
• Recovery tests : Recovery tests assess the clean room ' s ability to return to its specified conditions after a disturbance . These tests are crucial in evaluating the clean room ' s resilience to deviations .
• Temperature and relative humidity test : Monitoring these conditions over an agreed-upon period of time is critical to prove that the system is operating correctly . Temperature and relative humidity impact the clean room environment by ensuring that temperature-sensitive processes are within the specified range and that humidity levels do not compromise product quality .
• Micro tests : Microbiological tests are conducted to ensure the absence of harmful microorganisms in the clean room environment and that is why it ' s crucial to ensure their absence .
It is important to note that while these tests are typically categorised under IQ , OQ and PQ , the specific grouping of tests may vary for each project , tailored to its unique requirements and specifications . However , the detailed categorisation of tests for each project is beyond the scope of this article , which focuses on the critical aspects of HVAC validation .
THE CRITICAL 10 % DESIGN AIR-FLOW THRESHOLD A fundamental facet of HVAC validation is the strict adherence to the 10 % design air flow threshold . It is imperative that the airflows measured during AHU testing , and air-balancing activities remain within this threshold . Any deviations beyond 10 % warrant thorough investigation and a comprehensive explanation . This criterion aligns perfectly with the commitment to precision and quality .
Re-validation scenarios may include :
• HEPA filter failure : If HEPA filters experience issues during initial testing , they must be replaced , and the validation process must commence again .
• HEPA filter certificate : If HEPA filter serial numbers don ' t match their factory certificate , they must be replaced , and the validation must begin anew .
• Deep cleaning dilemmas : If post-deep cleaning inspections reveal shortcomings , they become a critical concern to address before proceeding with the validation process to avoid potential contamination .
• Airflow interruptions : Unexpected disruptions or changes to airflow during HEPA filter installation or other stages are significant concerns , necessitating re-testing of airflow and pressure differentials .
• Environmental evolutions : Significant changes in the clean room ' s environment , such as alterations in occupancy or equipment , may require re-validation to ensure continuity .
CONCLUSION In conclusion , the strategic sequence of HVAC validation testing in new clean room construction and existing facility refurbishments is a meticulous process that profoundly influences the clean room ' s functionality and adherence to stringent regulatory standards and ensures that tests do not have to be repeated . Emphasising air balancing , AHU testing , pressure cascade configuration and the unwavering adherence to the 10 % design air flow threshold underscores the commitment to precision and excellence .
To attain the highest levels of quality , compliance and safety in controlled environments , it is imperative to adopt a holistic approach to clean room validation . This approach places equal importance on the co-ordination of HVAC validation with process equipment validation , ensuring that all aspects of the controlled environment work in harmony , guaranteeing the integrity and reliability of critical processes . In the fast-paced conclusion to a project , the timing of validation activities toward the project ' s end adds a layer of urgency , making precise sequencing even more critical . RACA
ADDRESSING DEVIATIONS AND RE- VALIDATION SCENARIOS In instances where measured airflows wander beyond the 10 % threshold after the air balancing process or unexpected challenges arise during the tests , a systematic approach takes centre stage to rectify these discrepancies . This approach includes an in-depth root cause analysis , the implementation of necessary corrective actions and a detailed documentation of all findings .
“ It is imperative that the airflows measured during AHU testing , and airbalancing activities remain within this threshold .”
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RACA Journal I November 2023 www . refrigerationandaircon . co . za