Internal heat exchangers only improve natural refrigerant efficiency under specific conditions, review finds
bioengineer.orgA systematic review of 22 studies finds that internal heat exchangers (IHXs) can improve the efficiency of natural refrigerant systems, but only when the refrigerant and operating conditions are right. Hydrocarbon systems like propane and isobutane show consistent gains, while carbon dioxide systems need optimized discharge pressure and high IHX effectiveness. Ammonia and cascade systems are more situational, with benefits shrinking at very low evaporating temperatures.