How do natural refrigerants like CO2 and ammonia compare to traditional HFCs in terms of energy efficiency?

Natural refrigerants like CO2 and ammonia are generally more energy efficient than traditional HFCs. This is because they have lower compression ratios, which result in lower energy consumption. For example, CO2 refrigeration systems can achieve energy savings of up to 20% compared to traditional HFC-based systems. Additionally, natural refrigerants often require less refrigerant charge, which reduces the overall environmental impact of the system.