Heat Exchangers for Sustainable Energy Systems unites classical heat-transfer science with modern realities of decarbonization, electrification, and circular economy principles. This comprehensive, practice-oriented reference serves engineers, researchers, and practitioners designing efficient thermal management systems for sustainable energy applications. The book covers fundamental heat transfer mechanisms-conduction, convection, radiation, and phase change-alongside advanced exchanger technologies optimized for renewable energy systems. Content addresses compact heat exchangers, plate exchangers, shell-and-tube designs, finned surfaces, and emerging technologies including microchannel and printed circuit heat exchangers. Readers explore performance analysis, thermal-hydraulic optimization, materials selection, and manufacturing considerations. Key topics include heat exchanger network synthesis, pinch analysis, exergy analysis, and life cycle assessment for sustainability evaluation. The text examines applications across solar thermal systems, geothermal energy, heat pumps, waste heat recovery, thermal energy storage, and hydrogen production systems. Special emphasis is placed on integrating heat exchangers within circular economy frameworks and electrified energy systems. Through detailed examples and case studies, the material provides practical design methodologies and performance evaluation techniques. This essential resource equips professionals with tools for developing energy-efficient thermal systems that support decarbonization goals and sustainable energy transitions worldwide.