Which refrigerant has operating pressures that exceed 1000 PSIG?

The refrigerant that has operating pressures exceeding 1000 PSIG is R-744, also known as carbon dioxide (CO2). Carbon dioxide operates at high pressures, with normal operating pressures in many systems exceeding 1000 PSIG, especially in transcritical applications where R-744 is utilized. This is due to the unique thermodynamic properties of CO2, which allow it to be effective in various refrigerant cycles at elevated pressures.

The other refrigerants mentioned have much lower operating pressures. R-22 and R-12, for example, are halocarbon refrigerants with typical operating pressures well below the 1000 PSIG threshold. Similarly, R-134A operates effectively within a moderate pressure range, but it does not reach the high pressure levels encountered with R-744. Understanding the pressure characteristics of different refrigerants is critical in selecting the appropriate refrigerant for specific applications in refrigeration and air conditioning systems.