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Maintaining Long-Term Stability of Temperature, Humidity, Pressure, and Air Changes: Core Challenges in Animal Laboratory Engineering

Created on 01.22
Animal laboratories are essential infrastructure for life sciences research and preclinical drug evaluation. The reliability and reproducibility of experimental data, as well as animal welfare, depend heavily on precise and stable laboratory environmental conditions. Among the various environmental parameters, maintaining long-term stability of temperature, humidity, pressure differentials, and air change rates represents a core technical challenge in the design and construction of animal laboratories. This is not merely an engineering issue—it directly impacts the rigor and validity of scientific experiments.
Veterinary surgery room with equipment and stainless steel operating table.

I. Temperature and Humidity Control: Precision Beyond Comfort

Animals are highly sensitive to fluctuations in temperature and humidity. Even minor deviations can affect metabolism, immune responses, behavior, and gene expression, potentially introducing variability into experimental results.
Core Challenge: Laboratories must maintain temperature and humidity within specified ranges 24/7, 365 days a year (e.g., temperature ±1°C, humidity ±5%RH). This stability must be achieved despite external climate variations, heat generated by equipment, animal heat output, and human activity. Conventional comfort HVAC systems cannot meet these stringent requirements.
Solution Highlights:
  • Use high-precision, high-redundancy dedicated HVAC units with automatic control systems and sensitive sensors.
  • Carefully design airflow distribution to ensure uniform conditions throughout the room, including microenvironments within animal cages.
  • Employ well-insulated building envelopes to minimize thermal fluctuations.

II. Pressure Differentials: The Invisible Protective Barrier

Stable, directional pressure differentials are essential to prevent cross-contamination and protect animals, personnel, and the environment. For example:
  • In SPF (specific pathogen-free) animal rooms, positive pressure relative to adjacent corridors prevents external contaminants from entering.
  • In infectious or chemical experiment areas, negative pressure prevents hazardous substances from escaping.
Core Challenge: Pressure differentials are extremely small (typically 10–50 Pa, equivalent to the pressure of a light breeze), yet must withstand frequent disturbances such as door openings, personnel movement, equipment cycling, and airflow fluctuations. Maintaining dynamic stability over time is a major engineering challenge; failure to control pressure can compromise biosafety barriers.
Solution Highlights:
  • Implement variable air volume (VAV) supply and exhaust systems with high-sensitivity pressure sensors and rapid-response damper actuators.
  • The system must instantly adjust airflow to restore the target pressure differential whenever doors open or equipment cycles.
  • High-quality room sealing is a prerequisite for maintaining stable pressure control.

III. Air Change Rates: Balancing Air Quality and Energy Efficiency

Adequate air change rates dilute odors, heat, dust, and harmful gases (e.g., ammonia) generated by animals and provide a consistent supply of fresh air. National standards specify minimum air change rates for animal rooms of different levels.
Core Challenge: Achieving high air change rates (typically 10–20 ACH or more) while controlling energy consumption, noise, and animal stress due to high-velocity airflow. Systems must maintain stable airflow despite changes in duct resistance or filter loading.
Solution Highlights:
  • Employ energy-efficient HVAC equipment, such as electronically commutated (EC) fans, smart fresh-air ratio control, and heat recovery devices.
  • Monitor filter differential pressure and replace filters proactively to maintain design airflow.
  • Optimize airflow distribution to avoid direct drafts on animal cages.

IV. System Engineering: All Parameters Are Interconnected

Temperature, humidity, pressure differentials, and air change rates are interdependent. A change in one parameter often affects the others. For example:
  • Adjusting airflow to maintain pressure can impact temperature and humidity.
  • Altering air change rates can disturb pressure balance.
Maintaining long-term stability requires a coordinated, responsive engineering solution encompassing:
  • Laboratory process planning
  • Building envelope and insulation design
  • Precision HVAC systems
  • Automated control systems
  • Rigorous commissioning, validation, and ongoing maintenance
Any weakness in one component can compromise the entire environmental control system.

V. Conclusion

Overcoming these core challenges is essential for constructing compliant, reliable, and efficient animal laboratories capable of producing high-quality scientific data. Achieving this requires collaboration from all project stakeholders—particularly owners and experienced engineering teams—starting from the earliest design phase.
This article provides a clear analysis of the key technical challenges in animal laboratory environmental control, based on applicable design standards and engineering practice. For detailed, project-specific solutions and case studies, please refer to our specialized animal laboratory construction solutions page.
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