CAS technicians are NATE Certified. CAS technicians spend numerous hours each year (at least once each month) in factory-sponsored training to increase their skills and stay current on all makes of equipment. North American Technician Excellence, Inc. is the leading certification program for technicians in the heating, ventilation, air-conditioning, and refrigeration (HVAC/R) industry and offers the only testing supported by the entire industry. NATE certification is given for individual technicians. We also emphasize customer service skills as part of each technician’s training.