At what saturation temperature should you begin charging liquid refrigerant into the system?

• A. 32 F
• B. 36 F
• C. 40 F
• D. 34 F

Answer: (B)

The appropriate temperature to begin charging liquid refrigerant into a system is determined by the characteristics of the refrigerant being used and the conditions of the system. In general, it is vital to start charging at a temperature that allows the refrigerant to be in a liquid state, ensuring efficient and proper charging.

Starting at 36°F is optimal for many refrigerants, as it is a temperature that correlates well with the saturation point for some refrigerants like R-22. Charging liquid refrigerant at this saturation temperature helps ensure that the system receives the refrigerant in its liquid state, which is necessary for effective operation. Liquid refrigerant is critical for proper heat exchange within the evaporator, allowing for efficient cooling.

Choosing a saturation temperature that is too low may lead to charging vapor refrigerant instead of liquid, which can cause the compressor to operate inefficiently or even lead to potential damage. Therefore, 36°F is a balanced starting point, aligning well with common industry practices for ensuring that refrigerant is properly charged into the system.