EPA Section 608 Universal Certification ExamType II (High-Pressure Appliances)Medium
A technician is using a system-dependent (passive) recovery device to remove refrigerant from a small appliance. Which of the following conditions would make this type of recovery MOST challenging or impractical?
- AThe appliance has a very small refrigerant charge (e.g., 2 oz).
- BThe system contains a significant amount of non-condensable gases.
- CThe appliance's compressor is fully operational.
- DThe ambient temperature is very high.
Show answer & explanationAnswer & explanation
Correct answer: B. The system contains a significant amount of non-condensable gases.
System-dependent recovery relies on the system's own pressure or the pressure differential created by cooling the recovery cylinder. Non-condensable gases significantly increase system pressure and prevent efficient condensation of refrigerant in the recovery cylinder, making passive recovery very difficult or impossible.
Why the other options are wrong
- A. A very small charge might be recovered quickly, but the method itself wouldn't be impractical due to the small charge.
- C. An operational compressor would actually aid system-dependent recovery by helping to move refrigerant.
- D. High ambient temperature would make it harder to cool the recovery cylinder and create a pressure differential, but non-condensables are a more direct and severe impediment.
System-Dependent Recovery Limitations
Factors that can hinder or prevent the effective use of system-dependent (passive) refrigerant recovery methods.
- Relies on pressure differential.
- Non-condensables severely impede process.
- Less effective for deep vacuum or large systems.
Memory trick: Non-condensables are the 'blockers' of passive recovery!