Safety Cooling System for Chest and Upright Freezers. CO2 / LN2 safety cooling systems for connection to a 230 V emergency power system or for battery-powered operation (supplied with power by a battery provided with the system for around 60 h). The temperature in the cabinet is kept constant at a freely selectable value (0 to - 70 °C) by controlled injection of LN2 or CO2 when the main cooling system fails. For Chest Freezers with a volume of at least 70 l and Upright Freezers starting at a volume of 300 l storage space. Refrigerant vessel is not included in scope of supply.