What is a likely reason?

Recovery techniques · EPA 608 Type I. The correct answer, and the reasoning behind it.

Identifying refrigerants, access valves, passive recovery and solderless fittings.

The question

A refrigerator labeled R-134a has been off for hours at 72 °F. Its standing pressure is well below the chart value for R-134a at that temperature. What is a likely reason?

• AIt contains air or other noncondensable gases from a leak
• BSo little refrigerant is left that no liquid remainsCorrect answer
• CIt is overcharged with R-134a
• DIts compressor is running backward

Why “So little refrigerant is left that no liquid remains” is correct

A P/T chart applies only when liquid and vapor are both present. If most of the charge has leaked out, the remaining vapor sits below the saturation pressure for that temperature, so the reading cannot confirm the refrigerant.

Source: EPA: Test Topics

Why the other answers are wrong

• It contains air or other noncondensable gases from a leak — Noncondensables push the pressure above the chart value, not below it.
• It is overcharged with R-134a — Extra refrigerant does not lower the standing pressure below saturation.
• Its compressor is running backward — The unit is off, so the compressor is not affecting the reading.

Practice more of this

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