This book addresses the increasing energy demand and costs associated with the global refrigeration industry, primarily driven by the need for cooling. It proposes the substitution of vapour compression refrigeration systems (VCRS) with vapour absorption refrigeration systems (VARS), which operate on low-grade, renewable energy sources like solar, geothermal, and waste heat. Focusing on the absorber component of VARS, which plays a critical role in facilitating heat and mass transfer processes, the book provides a comprehensive overview of absorber configurations, including tray, packed bed, falling film, spray, bubble, and membrane absorbers. It offers guidance on selecting the appropriate absorber configuration considering their advantages and limitations in different operating conditions, as well as their numerical, experimental, and performance enhancement studies. The book will interest heating, ventilation, and air conditioning (HVAC) academic researchers, graduate students, and professionals involved in the advancement of sustainable refrigeration technologies, particularly absorber selection.