CO2 (R744) as refrigerant: Enviroment friendly, non flammable, non toxic and non ozone deplating regrigerant. Due to these advantages of the CO2 becomes popular again. CO2 systems are mainly used for labratory works, supermarket type food cooling and for many other low temperature applications.
CO2 refrigeration systems can be built in two different type; Transcritical System (one stage cooling) and Subcritical System (two stage cooling). These system have working pressures of 45 Bars (Subcritical) and 130 Bars (Transcritical). In both systems many safety valves needed to maintain the pressure control during in action.
Any technician who is not experienced or trained for CO2 refrigeration systems is under high health risk due to high pressure of the CO2 system. For example even the noise of the pressure relief valve during relieve of the exceeding pressure in the system in a power shutdown or during fault in the system.
All products have to be well isolated to protect all the vessels against ambiant temperature change.