After all the liquid has been removed from a large R-11 chiller, why must the technician still run vapor recovery?

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

After all the liquid has been removed from a large R-11 chiller, why must the technician still run vapor recovery?

• AA large amount of refrigerant remains as vapor in the shellsCorrect answer
• BThe vapor may be vented once the liquid is out
• CThe vapor is mostly air and must be checked
• DVapor recovery is only needed on R-123 chillers, not on R-11 chillers

Why “A large amount of refrigerant remains as vapor in the shells” is correct

A big chiller has a lot of internal volume, so many pounds of refrigerant are still present as vapor after the liquid is gone. Vapor recovery must continue until the appliance reaches 25 mm Hg absolute.

Source: EPA: Test Topics; 40 CFR 82.156(a), Table 1

Why the other answers are wrong

• The vapor may be vented once the liquid is out — Venting refrigerant vapor is prohibited.
• The vapor is mostly air and must be checked — The vapor is refrigerant, not mostly air.
• Vapor recovery is only needed on R-123 chillers, not on R-11 chillers — Both refrigerants need vapor recovery to reach 25 mm Hg absolute.

Practice more of this

More EPA 608 Type III practice questions, or see every EPA 608 practice test.