EPA Section 608 Universal Certification ExamType I (Small Appliances)Medium
A technician is performing a recovery on a small appliance with a non-operating compressor. To maximize the recovery rate using a system-dependent device, which of the following actions would be most beneficial?
- ACooling the recovery cylinder to create a pressure differential.
- BUsing a manifold gauge set with small diameter hoses.
- CConnecting only to the high-side port of the appliance.
- DHeating the recovery cylinder to increase its internal pressure.
Show answer & explanationAnswer & explanation
Correct answer: A. Cooling the recovery cylinder to create a pressure differential.
Cooling the recovery cylinder lowers its internal pressure, creating a greater pressure differential between the appliance and the cylinder. This differential helps draw refrigerant more effectively from the appliance into the recovery cylinder during passive recovery.
Why the other options are wrong
- B. Small diameter hoses create more resistance and slow down the recovery process; larger hoses are preferred.
- C. Connecting to both high and low sides is generally more effective for a complete recovery, especially with a non-operating compressor.
- D. Heating the recovery cylinder would increase its pressure, making it harder for refrigerant to flow from the appliance into the cylinder.
Passive Recovery Rate Enhancement
To maximize the recovery rate when using a passive (system-dependent) recovery device, cooling the recovery cylinder creates a larger pressure differential, drawing refrigerant more efficiently from the appliance.
- Applies to system-dependent recovery.
- Especially useful with non-operating compressors.
- Lower cylinder temperature = lower cylinder pressure.
- Greater pressure difference promotes faster flow.
Memory trick: Cool the tank, make the refrigerant yank!