Design and Standards for Laboratory Ventilation and Exhaust Systems
I. Definition of Laboratory Ventilation and Exhaust Systems
The ventilation and exhaust system in biopharmaceutical cleanroom engineering refers to a scientifically designed airflow organization and pressure control system that ensures indoor air quality meets cleanliness requirements. Its core functions include: controlling pollutant diffusion, maintaining pressure differential gradients, ensuring personnel safety, and stabilizing the experimental environment. According to international standards ISO 14644-1 and WHO GMP requirements, the system must achieve precise control of directional airflow (from clean areas to contaminated areas) and air changes per hour (ACH).
II. System Components and Key Technologies
1. Air supply system: Uses HEPA (High-Efficiency Particulate Air filters, compliant with EN 1822 standards) or ULPA filters, with filtration efficiency required to exceed 99.99% (for 0.3μm particles).2. Exhaust system: For biosafety laboratories (BSL-2/3 levels), BIBO (Bag-In/Bag-Out) filters and chemical disinfection devices must be installed, complying with NSF/ANSI 49 standards.3. Airflow organization: Employs unidirectional (laminar) or non-unidirectional (turbulent) airflow designs, with clean area air velocity typically at 0.45±0.1 m/s (ISO 14644-3).4. Pressure control: Uses VAV (Variable Air Volume) valves for dynamic pressure differential adjustments, with adjacent zone pressure differentials ≥5 Pa (EU GMP Annex 1).
III. International Standards and Design Guidelines
• ASHRAE 110-2016 (USA): Specifies performance testing methods for ventilation systems.• EU GMP Annex 1: Defines pressure differential and air change requirements for sterile drug manufacturing environments.• China GB 50457-2019: Design standards for cleanrooms in pharmaceutical industries.• Key parameters: Biosafety cabinet exhaust must be independently configured, with exhaust duct negative pressure ≥-250 Pa (CDC/NIH Biosafety in Microbiological Laboratories).
IV. Requirements for Special Applications
1. High-potency drug production areas: Exhaust air must undergo two-stage HEPA filtration (EU GMP Appendix 3).2. Virus-handling laboratories: Exhaust systems must feature in-situ leak detection (ISO 14644-3 Appendix B).3. Energy-efficient design: When heat recovery devices are used, cross-contamination risks must be eliminated (ASHRAE 170-2017).