In recent years, interest in utilizing secondary refrigerants in large industrial refrigeration systems has been increasing. This is due in part to a desire to reduce the quantity of primary refrigerant and to limit the primary refrigerant charge to the refrigeration equipment room. In many installations, the primary refrigerant is ammonia; however, the primary refrigerant also may be other synthetic refrigerants. Often, facilities are interested in reducing ammonia inventory due to increased regulation and scrutiny of ammonia refrigeration systems. Insurance companies, governmental bodies and other authorities having jurisdiction may look more favorably on systems with lower quantities of ammonia refrigerant.
This article will describe the benefits and disadvantages of using two indirect systems for industrial refrigeration: