"Variable Primary Flow Hydronic Systems"

December 11, 2019
7:00 AM to 9:00 AM
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The Union League of Philadelphia
140 South Broad Street
Philadelphia , PA 19102

"Variable Primary Flow Chilled Water Systems"

presented by Dr. William P. Bahnfleth, Ph.D., P.E. 

GBCI Approved | 1 CE Hour | 0920014275

Join us for an educational breakfast session!


  • Registration: 7:00am-7:30am
  • Breakfast: 7:30am-8:00am
  • Presentation: 8:00am-9:00am


Seating is limited, registration is open to the first 70 people.



Variable primary flow is being adopted in chilled water system design with increasing frequency as a lower cost, more efficient alternative to primary/secondary design that is not as susceptible to low delta T syndrome. Subtopics include a review of variable primary flow and primary/secondary system types; causes and effects of low delta T syndrome and potential remedies; design considerations for variable primary flow, and, comparisons of variable primary flow and primary/secondary flow taken from case study and research literature.

Speaker Bio:

William P. Bahnfleth, Ph.D., P.E.
Department of Architectural Engineering
The Pennsylvania State University
1426 South Pugh Street
University Park, PA 16801
[email protected]



William Bahnfleth is Professor and Director of the Indoor Environment Center in the Department of Architectural Engineering at the Pennsylvania State University (Penn State) in University Park, PA, where he has been employed since 1994. Previously, he was a Senior Consultant for ZBA, Inc. in Cincinnati, OH and a Principal Investigator at the U.S. Army Construction Engineering Research Laboratory in Champaign, IL. He holds BS, MS, and PhD degrees in Mechanical Engineering from the University of Illinois, where he also earned a bachelor of music degree in instrumental performance. His is a registered professional engineer.

At Penn State, Dr. Bahnfleth teaches undergraduate courses in HVAC fundamentals, system design, and controls and graduate courses in chilled water systems, hot water and steam systems, and indoor air quality. His research interests cover a wide variety of indoor environmental control topics including chilled water pumping systems, stratified thermal energy storage, protection of building occupants from indoor bioaerosol releases, ultraviolet germicidal irradiation systems, and others. He is the author or co-author of more than 170 technical papers and articles and 14 books and book chapters. He consults on the design of chilled water thermal energy storage systems and has been involved in more than 20 projects world-wide.

Dr. Bahnfleth is a fellow of ASHRAE, the American Society of Mechanical Engineers (ASME) and the International Society for Indoor Air Quality and Climate (ISIAQ). He is also a member of the Indoor Air Quality Association (IAQA), the International Building Performance Simulation Association (IBPSA), and the Society of Building Science Educators (SBSE). He has served ASHRAE in a variety of capacities, including Student Branch Advisor, Chapter Governor, Technical Committee and Standing Committee Chair, and as Director-at-Large, Vice President, Treasurer, and 2013-14 Society President. His honors include a 1st place ASHRAE Technology Award, Transactions Paper Award, Distinguished Service and Exceptional Service Awards, The Louise and Bill Holladay Distinguished Fellow Award, and the E.K. Campbell Award of Merit for service and achievement in teaching. He is also a recipient of the Penn State Engineering Alumni Society’s World-Class Engineering Faculty Award


This is an Employer Recognition Event! 


$30.00 Chapter Member

$25.00 YEA - Chapter Member

$0.00 Life Member with Chapter dues up-to-date

$40.00 Society Member

$50.00 Non-Member

$30.00 Student - Non-Member

$5.00 Student Chapter Member