EPA Section 608 Universal Certification ExamType I (Small Appliances)Medium
A technician is using a system-dependent (passive) recovery device on a small appliance with a non-operating compressor. Which of the following is crucial for maximizing the recovery of refrigerant from the appliance?
- AHeating the recovery cylinder to increase its internal pressure.
- BCooling the recovery cylinder to create a pressure differential.
- CPressurizing the appliance with nitrogen to push refrigerant out.
- DUsing a recovery machine with a high-capacity compressor.
Show answer & explanationAnswer & explanation
Correct answer: B. Cooling the recovery cylinder to create a pressure differential.
Cooling the recovery cylinder creates a lower pressure within the cylinder compared to the appliance, which helps draw the refrigerant out more effectively in a passive recovery system.
Why the other options are wrong
- A. Heating the recovery cylinder would increase its pressure, hindering refrigerant flow.
- C. Pressurizing with nitrogen is generally not recommended for small appliances, especially with a non-operating compressor, and can introduce non-condensables.
- D. System-dependent recovery does not use a recovery machine compressor; it relies on pressure differential.
Passive Recovery Maximization
For system-dependent (passive) recovery, cooling the recovery cylinder creates a pressure differential that draws refrigerant out of the appliance more effectively.
- Relies on pressure differences.
- Cooling the cylinder lowers its pressure.
- Increases recovery efficiency from the appliance.
- Used when the appliance's compressor is non-functional.
Memory trick: Cold tank, warm system, good flow, no problem!