1. When evaporation temperature is below -50℃, CO₂ could have sufficient evaporative pressure to meet the needs of food frozen at low temperature, and it will not produce negative pressure in the evaporator.

2. CO₂ is one gas of non-toxic, non-flammable and no odor, and its relative molecular mass is heavier than air, so it can be handled as the process of fluorine system refrigerant.

3. CO₂ has low environmental impact because its natural conditions.

4. low CO₂ viscosity, good heat transfer performance, utilizing the latent heat of endothermic, large cooling capacity per unit volume.