Thomas Ferdelman

Thomas (“Tom”) Ferdelman, age 89, of Kettering, passed away peacefully surrounded by his family on Tuesday, October 28, 2025. He was a beloved husband, father, grandfather, great-grandfather, and friend.

Born in Dayton, Ohio, to Clarence and Loretta (Hartke) Ferdelman, Tom graduated from Chaminade High School in 1954 and the University of Dayton in 1958. He married his sweetheart, Marilyn (Gross) Ferdelman, in 1959. Together they raised seven children and shared nearly 60 years of marriage before Marilyn’s passing in 2019. In 2023, Tom married Sharon (Werling) Ferdelman, and they shared cherished companionship in his later years.

Tom began his engineering career at Wright-Patterson Air Force Base (1958–1962), then joined Ahart & Associates (1962–1972), where he became a partner. In 1972, he joined HEAPY, where he served as President from 1976 until his retirement in 1998. He continued to provide leadership and contribute to special projects through 2008. During his tenure, Tom guided the firm through a significant era of growth, expanding its technical expertise and shaping its culture of integrity and collaboration. He was deeply respected for his steady leadership, thoughtful mentorship, and institutional knowledge that helped lay the foundation for the firm’s enduring success. He was also active in the professional organization, ASHRAE, serving in local, regional, and national leadership roles. He became an ASHRAE Fellow in 1998.

Tom was an active member of St. Charles Borromeo Catholic Church, where he served as a Eucharistic Minister and on the parish building committee, faithfully living out his Catholic values.

Outside of work, Tom was an avid fisherman who enjoyed countless trips with friends and family and was a member of Spring Run Farms. A lifelong University of Dayton Flyers basketball fan, he rarely missed an opportunity to cheer on his team.

Tom was preceded in death by his parents, Clarence and Loretta; and his wife, Marilyn. He is survived by his wife, Sharon; his children, Suzanne (Tim) McKenzie, Kathy (Mark) Fellows, Teresa (Jim) Wilson, Ann (David) Kelly, Joseph (Cindy) Ferdelman, Mary Ferdelman, and Steve (Amy) Ferdelman; 12 grandchildren, Amanda (Patrick) Klesmith, Robert (Emmie) Fellows, Katie McKenzie, Nick Wilson, Abby Wilson (fiancé Drew), Ryan (Emma) Kelly, Mike (Jamie) Kelly, Ben (Kaitlin) Ferdelman, Kayla Ferdelman, Logan George, Andy Ferdelman, and Nate Ferdelman; and six great-grandchildren, Faxon and Roger Fellows, Madeline Klesmith, Ford, Duke, and Estelle Kelly. He is also survived by his brother Don (Barb) Ferdelman.

Family will greet friends on Monday, November 3, from 5:00–7:00 p.m. at Routsong Funeral Home, 2100 E. Stroop Rd., Kettering. A Mass of Christian Burial will be celebrated on Tuesday, November 4, at 10:30 a.m. at St. Charles Borromeo Catholic Church, 4500 Ackerman Blvd., Kettering. Burial will follow at Calvary Cemetery.

In lieu of flowers, memorial contributions may be made to the Alzheimer’s Association or the Juvenile Diabetes Research Foundation (JDRF).