The four categories of HVAC career opportunities are: (1) Entry-Level Positions, requiring a high school diploma and on-the-job training; (2) Skilled Trades, requiring a post-secondary certificate or associate’s degree and apprenticeship training; (3) Technical and Engineering Roles, requiring a bachelor’s or master’s degree in a relevant field; and (4) Management and Leadership Positions, requiring a bachelor’s or master’s degree and significant industry experience. Each category offers a range of job roles and responsibilities, from installation and maintenance to design and management.