The HVACR 401: Heat Pump is part of a series of texts for HVACR professionals looking to further their knowledge of the industry. The book is the fourth addition to a series of HVACR training books. It begins with a review of the refrigeration cycle in comfort conditioning and gradually progresses to more advanced and in-depth topics. It was written with an emphasis on the service technician perspective, rather than the design engineer viewpoint, and covers topics such as electrical schematics, maintenance, geothermal heat pumps, and troubleshooting case studies. The books in the series contain a wealth of detailed and thorough reference content designed specifically for HVACR apprentices, entry-level technicians, and students. The HVACR series was developed based on industry-driven curriculum and encourages students to apply information to real-world scenarios. The series presents a wide range of important concepts, accompanied by useful instructor supplements, resource materials, lesson plans, and color illustrations and graphs. It was developed in conjunction with the Air Conditioning Contractors of America (ACCA), Plumbing-Heating-Cooling Contractors — National Association Educational Foundation (PHCC Educational Foundation), and the Refrigeration Service Engineers Society (RSES).