Why should water be kept circulating through the tubes of a chiller while its refrigerant is being evacuated?
Recovery techniques · EPA 608 Type III. The correct answer, and the reasoning behind it.
Liquid then vapor, heating oil, protecting water tubes, and high-pressure cut-outs.
The question
Why should water be kept circulating through the tubes of a chiller while its refrigerant is being evacuated?
- To keep the purge unit running during recovery
- To keep the water in the tubes from freezingCorrect answer
- To cool the recovery unit's compressor
- To stop the oil from foaming in the sump
Why “To keep the water in the tubes from freezing” is correct
As pressure drops during evacuation, the remaining refrigerant boils at lower and lower temperatures and can chill the tubes below 32 °F. Circulating the water, or draining it, prevents the water from freezing and cracking the tubes.
Source: EPA: Test Topics
Why the other answers are wrong
- To keep the purge unit running during recovery — The purge unit does not depend on water flow in the tubes.
- To cool the recovery unit's compressor — The chiller tube water does not cool the recovery machine.
- To stop the oil from foaming in the sump — Oil foaming is not the reason for circulating water.
Practice more of this
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