For Graham Cook, six years of semi-retirement was enough. Cook, the former president of Cook’s Mechanical in Nashville, has joined the Alpha Energy Solutions’ Tennessee office as a sales representative specializing in HVAC work. Cook’s territory will include all of east Tennessee. “I was tired of being retired,” Cook said during his orientation in Louisville in March. “I’m glad to be getting back to work and looking forward to seeing my contacts in the business.” Cook joins a rapidly growing…