How many PSI of non-condensables gases are present when the condenser outlet pressure is 151 PSIG?

The presence of non-condensable gases in a condensing system can significantly affect the performance and efficiency of that system. When the outlet pressure of the condenser is measured at 151 PSIG, it indicates the pressure of the vapor phase of the refrigerant and any non-condensable gases present in that section of the system.

Non-condensable gases, such as air, can accumulate in the condenser and can impact the overall system pressure. When the condenser outlet pressure is 151 PSIG, it is not solely representing the pressure exerted by the refrigerant. Instead, the total gauge pressure takes into account both the refrigerant and the non-condensables.

In general, the actual partial pressure of the non-condensables can be derived by subtracting the expected saturation pressure of the refrigerant at a particular temperature from the total pressure being measured. This approach is necessary in determining how much non-condensable gas is in the system because ideal conditions generally assume minimal non-condensables.

Given that the correct answer identifies the presence of 16 PSI of non-condensable gases, it implies that the refrigerant in the system is not fully condensing, and the remaining pressure (the difference between the total pressure and the saturation pressure