At what temperature does R-12 refrigerant boil?

R-12, also known as dichlorodifluoromethane, is a refrigerant that has a specific boiling point at atmospheric pressure. The boiling point of R-12 is approximately -21.7 degrees Fahrenheit. This temperature is significant in refrigeration applications as it indicates the conditions under which R-12 changes from a liquid to a gas, which is a key operation principle in refrigeration cycles.

Understanding the boiling point is crucial for technicians as it impacts the refrigerant's performance in the system. When the temperature of R-12 drops below -21.7 degrees Fahrenheit, it will start to evaporate, absorbing heat from the surrounding environment, which is the principle behind its use in refrigeration and air conditioning systems.

The other temperature options do not correspond to the boiling point of R-12, thereby making them incorrect in this context.