Abstract: An integrated refrigeration and air conditioning plant working in a cascade cycle with two different refrigerants for the low and high temperature circuits. The low temperature segment works with an ozone friendly synthetic refrigerant with a minimal amount of refrigerant charge, while the upper stage operates with another ozone friendly refrigerant with much lesser global warming potential than the one in the low stage. The upper and/or medium temperature circuit also services the air conditioning needs of the environment where the refrigerated equipment is located, such as the shop floor of a supermarket or a laboratory housing the cabinets that keep refrigerators.

Abstract: An integrated refrigeration and air conditioning plant working with environmentally friendly natural refrigerant carbon dioxide (CO2) and an ozone friendly non CO2 refrigerant. The low temperature refrigeration is provided by evaporating CO2 and the fluid is used as a secondary refrigerant, predominantly in liquid mode, for medium temperature refrigeration. The heat rejection from CO2 occurs to another upper stage cascaded refrigeration system that operates with a ozone friendly non CO2 refrigerant. Since air conditioning applications require cooling at temperatures higher than refrigeration for food sector, cooling for this range is derived from the non CO2 refrigerant.