Harrison A. "Hap" Pollets, 77, a retired owner and formerly vice president and president of Orange County Plumbing Supply, Middletown, N.Y., died July 17 at Mount Vernon Hospital, Mount Vernon, N.Y. He was the father of Paul Pollets of Seattle, Wash., the founder of Advanced Radiant Technology, one of the country's top radiant heating contractors. A World War II Army Air Corp veteran, he was also a former member of the Middletown Jaycees, the Middletown Volunteer Fire Dept. and the Elks Club.