The HVAC Certification Process ExplainedHigh school diploma. Getting a high-school diploma is the first step you should take in pursuing a career as an HVAC technician.HVAC Training. Like any profession, it is important to have a solid base in HVAC-related subjects through classroom training.HVAC Apprenticeship. Local associations like the Air Conditioning Contractors of America and the Associated Builders and Contractors run HVAC apprenticeship programs that typically last three to five years.Practical Experience. Most certifications require you to have a bare minimum of 12 months of practical experience, so working under an HVAC contractor to acquire on-the-job training is necessary.Additional Certifications. Agencies like the North American Technical Excellence (NATE), HVAC Excellence, Refrigeration Service Engineers Society (RSES), and Refrigeration Engineers and Technicians Association (RETA) offer additional specialty certifications.