Aux 2 Unit 9 Quiz 9

Correct Answer:
C) Monitor the system for vacuum retention before charging with refrigerant

Explanation:
After evacuation, the system should be monitored to ensure it holds the vacuum, indicating there are no leaks before charging with refrigerant.

Correct Answer:
B) Higher temperature differential across the condenser

Explanation:
Air in the system leads to an increased temperature differential in the condenser due to the added non-condensable pressure, which adversely affects the system's performance.

Correct Answer:
C) It can lead to higher condenser pressure and reduced system efficiency

Explanation:
Air is a non-condensable gas and does not participate in the refrigeration cycle. Its presence increases the system's pressure, particularly in the condenser, which reduces efficiency and may lead to higher energy consumption and potential damage.

Correct Answer:
B) Using a vacuum pump to evacuate the system

Explanation:
A vacuum pump effectively removes air and moisture from the system before it is charged with refrigerant. This ensures the system starts operation without non-condensable gases that could impair efficiency.

Correct Answer:
B) During system servicing or repairs

Explanation:
Air may enter the system when it is opened for maintenance or repairs, particularly if the system is not properly evacuated before re-sealing.

Correct Answer:
C) An air purger

Explanation:
An air purger is designed to remove non-condensable gases such as air from a refrigeration system while it is operating, maintaining system efficiency and preventing high pressure in the condenser.

Correct Answer:
C) Improper evacuation procedures

Explanation:
If a system is not thoroughly evacuated before charging, air and moisture can remain trapped inside, leading to operational issues.