Air Conditioning Certification (A-02) Practice Exam

When determining the pressure of refrigerant R12 after it leaves the condenser, it's important to understand the relationship between pressure and temperature for refrigerants, which is typically described by pressure-temperature (P-T) tables or refrigerant property charts.

In this scenario, R12 enters the condenser at a pressure of 116.9 psig, which corresponds to a certain temperature and allows the refrigerant to start condensing. As it passes through the condenser, the refrigerant releases heat and changes phase from vapor to liquid. At a temperature of 80°F, the pressure of R12 can be found using its P-T chart.

According to the properties of R12, at 80°F, the saturation pressure of the refrigerant is around 84.1 psig. This indicates that, in a proper condensing process, if the refrigerant is indeed at saturation, it should reflect that pressure at this temperature. Therefore, the approximate pressure when the refrigerant R12 vapor exits the condenser at 80°F is correctly identified as 84.1 psig.

This value shows that the refrigerant has adequately condensed at the specified exit temperature and maintains a pressure consistent with the saturation point for that temperature, aligning with the understanding of how refrigerants