Overview
HVAC verification testing evaluates the ability of
BSL-3/ABSL-3 and BSL-4/ABSL-4 facilities to maintain directional airflow and containment during normal operations and simulated failure conditions.
Testing verifies that airflow is maintained from
“clean" areas toward “potentially contaminated" areas and that the HVAC system is designed so airflow is not reversed at the containment barrier under failure conditions, consistent with the Biosafety in Microbiological and Biomedical Laboratories (BMBL), 6th Edition (BSL-3 Paragraph D.9 and ABSL-3 Paragraph D.5.e).
For Select Agent-registered BSL-3/ABSL-3 facilities, HVAC verification testing is performed in accordance with applicable
Federal Select Agent Program requirements and guidance. NIH testing procedures and reporting are based on these requirements and the BMBL.
When HVAC Verification Is Required
HVAC verification testing is performed in accordance with BMBL BSL-3 Paragraph D.15 and ABSL-3 Paragraph D.11.
Testing Milestone
|
Frequency |
|---|
| Before Initial Operation | Once, prior to initial operation |
| Annual Verification | Every 12 months |
| After Significant Facility Modifications | As required |
HVAC and Power Verification Testing
HVAC and power verification testing evaluates facility performance under a variety of simulated failure scenarios. Testing may include:
-
Normal Power Failure: Simulates loss of normal facility power and the transition to emergency power.
-
Air Handler and Exhaust Fan Failures: Simulates single or multiple fan failures, as applicable, based on system configuration and redundancy.
-
HVAC Control Sequences: Evaluates the response of HVAC systems and associated controls during normal and failure conditions.
The specific test scenarios are determined based on the facility's HVAC configuration, redundancy, controls, and containment requirements.
Differential Pressure Monitoring
Differential pressure monitoring is the primary quantitative method used to evaluate directional airflow during normal operations and simulated failure conditions.
Differential pressure data are collected and analyzed to evaluate the
magnitude and duration of pressure changes between containment spaces and adjacent areas. These data help determine whether the facility maintains the intended directional airflow and containment during each test scenario.
Performance Criteria
In addition to applicable acceptance criteria, HVAC verification evaluates several key areas of facility performance:
Containment Performance
The HVAC system is evaluated for its ability to
maintain containment and prevent positive pressurization events at the containment barrier during each test scenario.
While regulatory acceptance criteria consider overall facility containment, system performance is also evaluated at individual containment-barrier doors. Airflow reversals through closed doors at the containment barrier during failure scenarios should be avoided.
System Functionality
Electrical and mechanical systems, components, controls, and sequences of operation associated with BSL-3/ABSL-3 containment are evaluated to verify that they
perform as designed.
Any system, component, or sequence that does not perform as intended during testing is identified, recorded, and documented for evaluation and corrective action, as appropriate.
Pressure Monitoring Accuracy
Facility differential pressure monitoring systems are evaluated by comparing
Building Automation System (BAS) pressure trends with measurements collected using independently
NIST-certified micromanometers.
Verifying monitoring accuracy is critical because potential containment events may occur outside the annual verification testing period. Accurate BAS monitoring helps ensure that abnormal pressurization conditions can be
detected, recorded, controlled, and appropriately addressed during routine facility operation.
