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Oct 27, 2026

FPC2026: ASHRAE 170 and speakers show way ahead for TcAF in the US

As surgery has evolved, so has the airborne risk environment in the operating room. Yet, many operating rooms are designed on ventilation principles developed many decades ago.


At the FPC Seminar + Expo in Orlando, Kathy Warye (CEO, Infection Prevention Partners), Mark Schwartz (Facility Director, URMC) and Robert Booth (Senior Healthcare Consultant, Oncore) reviewed a different approach to operating room ventilation. The session, “Rethinking Ventilation: Temperature-controlled Air Flow for the Operating Room,” brought together perspectives from infection prevention, healthcare facilities engineering and compliance. 

A key development came from the preceding presentation on ASHRAE 170 where the speaker, Aaron Johnson a voting member of ASHRAE 170 and Director of Healthcare Operations at TLC Engineering Solutions, discussed ASHRAE 170’s acceptance of unconventional ventilation types and clarified that “there are no objections to TcAF”.  The corresponding slide included a picture of an Opragon hybrid installation. The statement followed several years of review including a series of independent scientific studies presented to the 170 Committee. The steps to reach compliance with an Opragon TcAF design were also listed, specifically how to interpret requirements that are oriented to conventional ventilation systems. 

The TcAF session reviewed:

  • Why an alternative to conventional Laminar Air Flow is needed to meet the airborne challenges in the modern surgical environment,
  • The science of TcAF which utilizes a temperature differential and gravity to make the entire room ultra clean,
  • The experience of the University of Rochester Medical Center (NY) in reviewing, installing and using a TcAF system, and
  • How TcAF performance was validated for compliance with the ASHRAE 170 standard.

Together, these discussions provide a foundation for facilities, designers, architects and health departments to further explore TcAF ventilation as an alternative for the modern operating room. 


TcAF is currently installed, or being installed, in four US states, with additional projects in other states underway. 

Thank you to the speakers, hosts and everyone who contributed to an important discussion about the future of operating room ventilation. For any further questions, please contact us.