In recent years, thermal control systems performance has improved in numerous ways due to developments in control theory and information technology. Efforts have been made to produce more efficient heat exchangers by employing various methods of heat transfer enhancement. This book discusses the characteristics, types and emerging applications of heat exchangers. Chapter One presents a short review of advanced heat exchangers thermal designs and manufacturing. Chapter Two presents an empirical relationship between the pressure drop coefficient and the angle of inclination of porous media. Chapter Three studies the utilisation of heat accumulation in control of cyclic systems. Chapter Four describes and introduces the numerical simulation methodologies for thermal modeling of crossflow heat exchangers.