This short course focuses on Generation 2 and 3 heat pumps and rooftop units (RTUs). Participants will learn the operating principles, key components, and troubleshooting techniques for both systems. The course covers heat pump cycles, efficiency improvements, and their applications in heating and cooling. It also includes the design, installation, and maintenance of RTUs in commercial settings. Through hands-on practice, participants will gain the skills to diagnose and resolve common issues related to refrigerant, electrical systems, and airflow, ensuring optimal performance of heat pumps and rooftop units.