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Environmental conditions include atmospheric pressure, ambient temperature, atmospheric humidity, as well as the concentration of impurities such as CO2 in the air. These conditions vary depending on the region and climate, resulting in different performance levels even for the same air separation unit. 1) The effect of atmospheric pressure. The atmospheric pressure fluctuates around 0.1 MPa. A decrease in atmospheric pressure will increase the compression ratio of the air compressor. A decrease in atmospheric pressure of 0.01 MPa increases the compression ratio of air compressors by 6% to 8%, thereby raising the energy consumption for compression. Furthermore, as the mass-to-volume ratio increases (density decreases), the exhaust volume of the air compressor decreases, which in turn reduces the oxygen production volume; as a result, the power consumption per unit of oxygen produced increases. 2) Influence of ambient temperature. An increase in ambient temperature reduces the exhaust volume of the air compressor and increases its shaft power. For every 30°C increase in ambient temperature, the shaft power increases by approximately 1%. Furthermore, an increase in ambient temperature also raises the exhaust temperature of the air compressor, increasing cooling losses; more cooling capacity is required to compensate for these losses, which ultimately leads to increased energy consumption. 3) Effect of air humidity. As the humidity of the air increases, a portion of the compressor’s work is spent on compressing water vapor, resulting in an increase in the shaft power required by the air compressor. 4) The influence of impurities in the air. The increased level of impurities in the air raises the load on the molecular sieve adsorbers for purification.