What problem can moisture left in a system cause?
Dehydration and evacuation · EPA 608 Core. The correct answer, and the reasoning behind it.
Evacuating to remove air and moisture at the end of service.
The question
What problem can moisture left in a system cause?
- Acids and sludge, and ice at the metering deviceCorrect answer
- Lower head pressure and better efficiency
- Faster oil return to the compressor
- Higher ozone depletion potential of the refrigerant
Why “Acids and sludge, and ice at the metering device” is correct
Moisture reacts with refrigerant and oil to form acids and sludge that damage compressors and motor windings. It can also freeze at the metering device and block flow. Evacuation removes it.
Source: EPA: Test Topics
Why the other answers are wrong
- Lower head pressure and better efficiency — Moisture harms performance; it does not improve it.
- Faster oil return to the compressor — Moisture does not help oil return.
- Higher ozone depletion potential of the refrigerant — Moisture does not change a refrigerant's ODP.
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