Which of the following is not considered a desirable property of a good refrigerant?

• A. Low boiling point
• B. Low toxicity
• C. High boiling point
• D. Good thermal conductivity

Answer: (C)

A good refrigerant possesses several key characteristics that enhance its efficiency and safety in refrigeration and air conditioning systems. One of these characteristics is a low boiling point, which allows the refrigerant to evaporate and absorb heat effectively, resulting in efficient cooling. Low toxicity is essential for ensuring safety in case of leaks, making it suitable for use in occupied spaces. Additionally, good thermal conductivity is important as it facilitates effective heat transfer, improving the system's performance.

On the other hand, a high boiling point is not considered a desirable property for a refrigerant. A high boiling point means that the refrigerant would require more heat to evaporate, reducing its efficiency in absorbing heat from the environment and potentially leading to less effective cooling. Thus, while low boiling points enhance performance, high boiling points do the opposite, making it undesirable for an effective refrigerant. This is why the option indicating a high boiling point is the correct answer in identifying the property that does not align with the characteristics of a good refrigerant.