Fencl pioneered the use of ultraviolet germicidal irradiation in HVAC ductwork fabrication systems, the company said, earning 17 patents and writing several chapters in American Society of Heating, Refrigerating and Air-Conditioning Engineers handbooks. He was also an ASHRAE fellow.

“Forrest was a tremendous leader, great friend and mentor to me and so many others,” said Dan Jones, president and co-founder of UV Resources. “He was a man of exceptional character and integrity who would do what was right and courageous no matter the pressures to do otherwise. Forrest will be sorely missed by everyone who knew him.”

From 1995 to 2002, Fencl was CEO at Steril-Aire, and worked for 25 years at Farr Co., now known as the Camfil Group.

William P. “Bill” Bahnfleth, professor of architectural engineering at Penn State University and 2013-2014 president of ASHRAE, said Fencl was an important figure in HVAC construction.

 “Forrest had a profound impact on the development of HVAC and R applications of ultraviolet germicidal radiation,” Bahnfleth said. “He contributed to the development of modern UVGI technology as evidenced by his 17 patents, founded two of the major manufacturers of UVGI equipment, and devoted considerable effort to educating the professional community about the benefits of properly applied UVGI.”