Alumni create new endowment in memory of Herrick Labs professor David Tree

David Tree served as a professor and researcher at Purdue’s Herrick Labs for nearly 50 years. Now, some of his former students have created an endowment in his name to support future graduate students in mechanical engineering.

David Tree (1936-2016) served the School of Mechanical Engineering at Purdue as a professor, researcher, and administrator for nearly fifty years.

NOTE: Dennis O’Neal is matching all donations to the David Tree Graduate Support Endowment in Mechanical Engineering, up to $20,000, on Purdue Day of Giving, Wednesday April 24.

David Tree was born in Utah in 1936. After a B.S. and M.S. from Brigham Young University, Tree came to Purdue in 1963 to serve as an instructor, while also conducting his Ph.D. research at Herrick Labs (now the largest academic HVAC lab in the world). He ended up staying at Purdue for nearly 50 years as professor, researcher, and administrator. He died in 2016 at age 80.

“David Tree was such a good person,” said Patricia Davies, who joined the Purdue faculty in 1987 and became director of Herrick Labs in the 2000s. “I always appreciated his kindness and support when I came to Purdue as a young faculty member. He gave time and resources to people at the labs generously and was the embodiment of the Herrick spirit.”

While at Purdue, Tree advised 59 graduate students in thermal sciences research. He served as Assistant Head of the School of Mechanical Engineering, and Assistant Director of Industrial Research Administration in the Division of Sponsored Programs. Perhaps most significantly, in 1972 he worked with Ray Cohen and Werner Soedel to create the Herrick Conferences — now the country’s largest conference devoted to air conditioning and refrigeration research.

Branches of the Tree

One of Tree’s students, Dennis O’Neal (Ph.D. ’82), hadn’t initially planned for a career in academia. He grew up an Air Force brat, but his father had stressed the importance of getting a college education. He was a math and science whiz, and even tutored some of his teammates on his high school basketball team. That led him to enroll at Texas A&M University and study nuclear engineering.

While pursuing his master’s at Oklahoma State University, O’Neal learned that one of his faculty advisors had studied under David Tree at Purdue. After graduating and getting a job at Oak Ridge National Laboratories, he then had the chance to meet Tree at the Herrick Conferences. “When I visited Purdue, it felt like home,” O’Neal said. “The faculty were very personable and the graduate students I met with spoke very highly of Dave as an advisor. So I chose to come to Purdue and get my Ph.D. with Dave.”

Dennis O'Neal (Ph.D. '82) conducted research on frost formation at Purdue's Herrick Labs, under the supervision of David Tree. O'Neal himself then became a professor and administrator, at Texas A&M and Baylor University.

O’Neal conducted his Ph.D. research at Herrick Labs, where he and Tree studied the effects of frost formation on the performance of heat exchangers. They spent many hours at Herrick’s psychrometric chambers, which tested HVAC equipment at different temperature and humidity conditions. O’Neal finished his Ph.D. in 1982.

The duo also attended annual meetings of ASHRAE, the American Society of Heating, Refrigerating and Air-Conditioning Engineers. “Dave had this tradition of having dinner with all of his former grad students on the Monday night of the ASHRAE meeting,” remembers O’Neal. “When I started to teach and have my own graduate students, I carried on that tradition. All of my students met Dave, who was kind of their academic grandfather! To this day, I continue to look forward to the tradition of dinner with my former graduate students on the Monday night of the ASHRAE meeting — and that’s all because of Dave.”

O’Neal returned to Texas A&M and served there for 29 years as a professor, head of mechanical engineering, and associate dean for research. In 2012, he moved to Baylor University and served as dean of their engineering program, until retiring in 2022. “Dave was really an inspiration for all of that,” O’Neal said. “I’ve always aspired to treat my graduate students the way Dave treated me.”

During his time at Purdue, David Tree (left) supervised many graduate student researchers, including N.K. Anand (Ph.D. '83) (right).

Giving Back

Now 40 years on from his time at Purdue, O’Neal wanted to show his appreciation in a tangible way. He collaborated with another of Tree’s students, N.K. Anand (Ph.D. ’83), who followed O’Neal to Texas A&M, and now serves as their Vice Provost for Faculty Affairs. Together, they created the David Tree Graduate Support Endowment in Mechanical Engineering.

“My motivation is to give back,” said O’Neal. “When I attended Purdue, we lived in married student housing, and I walked to Herrick Labs. We couldn’t have survived without those graduate fellowships. I’ve seen firsthand how important they are for grad students.”

O’Neal has also seen firsthand how Boilermakers have impacted the world. “The graduate program there at Purdue has the potential to transform lives in a positive way,” he said. “The people that walk out of those labs go into industry, or national laboratories, or NASA or places like that, and become technology transformers. Just look at my field of heating and cooling. They’re not only creating comfortable homes; these folks are designing the cooling systems for everything from microchips to automobiles. Investing in these grad students one of the best ways to make a positive impact on society.”

NOTE: Dennis O’Neal is matching all donations to the David Tree Graduate Support Endowment in Mechanical Engineering, up to $20,000, on Purdue Day of Giving, Wednesday April 24.


For more information, or to donate to the David Tree Graduate Support Endowment in Mechanical Engineering, please contact Christina Starace, Senior Director of Development, at (317) 946-2414, or


Writer: Jared Pike,, 765-496-0374