From Mr. HVAC
This is the best book I come across for general HVAC and refrigeration knowledge. Whether you are a new technician or someone with a lot of experience, this book belongs on your bookshelf. It is an invaluable resource guide.

Amazon Description:
Modern Refrigeration and Air Conditioning is focused on closing the gap from students to technicians with our commitment to top-quality coverage of fundamentals and the latest technology. This classic is an excellent blend of theory, skill development, and service techniques to help you learn how to install and service refrigeration and HVAC systems. Technical content has never been more up-to-date. A logical and progressive organization, rich learning pedagogy and features, a superior art program, and readability contribute to Modern Refrigeration and Air Conditioning’s highly accessible nature. This edition has been revised with improved instructional design to help teach and retain students. Included are improved assessments and enhanced content on fundamentals such as electrical theory and troubleshooting. Relevant career and workplace readiness content prepares students for a successful career in the HVACR industry.