Ventilation Effectiveness for Laboratories (VEL) Working Group

Lead: Kishor Khankari, Ph.D., AnSight LLC, Ann Arbor, Michigan


Often high airflow rates or air change rates per hour (ACH) are specified to cover the risk of chemical exposure in laboratory spaces. Although high supply airflow rates can reduce the overall concentration of contaminants, they may not ensure acceptable concentration levels everywhere in the occupied zone. Locations of high concentration, especially those in the breathing zone of occupants, can pose potentially higher exposure risk. Ideally the clean supply air should sweep the contaminants away from the laboratory space without significant recirculation and stagnation, which can promote high concentration levels. At the same time, the clean air should not escape or short-circuit the space without collection and removal of contaminants. The design of HVAC systems and flow path of contaminants are among several important factors that can determine the effectiveness of laboratory ventilation systems. Ventilation effectiveness combined with energy efficiency can make the laboratories safe and sustainable.


The main goal of this group is to create an awareness about ventilation effectiveness for laboratories (VEL) among architects, engineers, facility managers, owners, and others who are involved in the design, operation, and maintenance of laboratories.


The I2SL VEL working group will address the following questions:

  • What is ventilation effectiveness for laboratories?
  • How does airflow distribution in laboratories affect the health and safety of occupants?
  • What are the hazards that can be controlled with ventilation?
  • How are ACH and VEL related? Why should we care about VEL in addition to ACH?
  • Is VEL the same for all types of laboratories? Does the definition of VEL change with the type of laboratory?
  • How are lab safety and VEL related?
  • How are energy efficiency and VEL related (efficiency versus effectiveness)?
  • Can high levels of VEL be implemented to make labs safe?
  • Could high levels of VEL be implemented to make labs more energy-efficient?
  • How to determine VEL (computational fluid dynamics [CFD] approach and field testing approach)?
  • What parameters affect VEL?
    • ACH
    • Lab layout (locations and number of supply, return, and fume hoods)
    • Diffuser types
    • Furniture layout and other obstructions to airflow
    • Sensible heat sources
    • HVAC design (chilled beams, overhead supply, and demand control ventilation, etc.)
  • How can VEL be specified as a design parameter? How can VEL be specified?
  • Can VEL be measured, and what tests are appropriate?
    • Airflow visualization
    • Velocity
    • Temperature distribution
    • Tracer gas migration (dilution and removal)
  • Can VEL be monitored?
  • Can VEL be used during commissioning?
  • What are the research and development needs related to VEL?


  • Define VEL
  • Develop guidelines for application of VEL
  • Demonstrate the use of CFD for predicting VEL
  • Develop guidelines for testing and validating VEL
  • Education
  • Seminars
  • Presentations
  • Conference participation
  • Specialized publications
  • Promote research and development

Committee Composition

Design engineers, facilities managers, owners, architects, EH&S professionals, industrial hygienists, commissioning agents, laboratory equipment manufacturers, field testing experts, CFD experts, and government agencies are encouraged to participate.

Get Involved

If you would like to join the working group, contact Kishor Khankari.