EPA Section 608 Universal Certification ExamCoreEasy

A technician is evacuating a system to remove non-condensables and moisture. What is the primary purpose of evacuating a refrigeration system to a deep vacuum?

  1. ATo test for leaks in the system.
  2. BTo boil off moisture and remove non-condensable gases.
  3. CTo remove all refrigerant from the system.
  4. DTo increase the system's cooling capacity.
Show answer & explanation

Correct answer: B. To boil off moisture and remove non-condensable gases.

Evacuating a refrigeration system to a deep vacuum lowers the pressure to a point where any moisture present will boil at room temperature and be removed as vapor, along with any non-condensable gases.

Why the other options are wrong

  • A. While a vacuum can hold, it's not the primary method for leak testing; pressure decay or electronic leak detectors are used.
  • C. Refrigerant is removed during recovery, not deep vacuum evacuation.
  • D. While a properly evacuated system improves efficiency, increasing cooling capacity is not the primary purpose of evacuation itself.

Deep Vacuum Evacuation

The process of reducing the pressure within a refrigeration system to a very low level (deep vacuum) to remove moisture and non-condensable gases.

  • Lowers the boiling point of water, allowing it to vaporize at ambient temperatures.
  • Removes air and other non-condensable gases that can cause high head pressure.
  • Essential for system efficiency and longevity.
  • Requires a vacuum pump and micron gauge.

Memory trick: Vacuum makes water vanish and air vanish.

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