As an alternative to using CFCs and HCFCs in refrigeration systems in supermarkets, plants have been developed in Brazil that use secondary fluids. These plants initially were conceived with the purpose of reducing the quantity of refrigerants in the plant. The refrigerant is limited to the central plant, and the secondary fluid transports the "cold" from the plant to the consumer's point of sales (display cases and warehouses). Subsequently, it was possible to eliminate halogen gases from the system by using ammonia.