Water present in the system can freeze if

• A. A large vacuum pump is used for evacuation
• B. The condenser is overheating
• C. The system is evacuated to atmospheric pressure
• D. The refrigerant is fully charged

Answer: (A)

Deep vacuum during evacuation creates very low pressure inside the system, which makes any moisture boil at a much lower temperature and absorb heat from its surroundings. As water boils and heat is removed, the remaining liquid and surfaces cool enough to freeze, so moisture can turn into ice on components. A large vacuum pump achieves this deep vacuum, making freezing of water more likely. In contrast, an overheating condenser raises temperatures rather than cooling them, evacuating to atmospheric pressure removes the deep vacuum and reduces the cooling effect, and simply having the refrigerant fully charged doesn’t create the conditions needed for water to freeze.