What is the evaporation temperature of R-134A at 0 psig?

• A. -10 F
• B. -15 F
• C. 0 F
• D. 5 F

Answer: (B)

The evaporation temperature of R-134A at 0 psig is indeed around -15°F. This is based on the refrigerant's properties and its pressure-temperature relationship.

R-134A, a hydrofluorocarbon (HFC) refrigerant, has a specific saturation pressure at various temperatures. When considering a pressure of 0 psig, which is equivalent to atmospheric pressure, the saturation temperature for refrigerants is significantly lower due to the low pressure.

At 0 psig, R-134A does not have enough pressure to remain in a gaseous state at temperatures above -15°F. This means that at this pressure, the refrigerant would undergo a phase change from liquid to vapor at the defined temperature of approximately -15°F. This temperature is critical for HVAC (heating, ventilation, and air conditioning) applications, as it determines the efficiency of the refrigeration cycle and system performance under varying operational conditions.

Understanding these relationships helps technicians in diagnosing system issues and ensuring proper refrigerant management in line with EPA regulations for handling refrigerants.