Fencl helped developed the use of ultraviolet germicidal irradiation for the HVAC market, company officials said. He had been awarded 17 HVAC construction patents and wrote several American Society of Heating, Refrigerating and Air-Conditioning Engineers publications on the use of ultraviolet equipment to kill germs.

The society named him lifetime fellow in 2010.

“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.”