EPA Section 608 Universal Certification ExamType I (Small Appliances)Medium
A technician is preparing to recover refrigerant from a small appliance. To prevent the introduction of air into the recovery cylinder during connection, what is the best practice?
- AConnect the hoses quickly to minimize air exposure.
- BPurge the recovery hoses with nitrogen before connecting them.
- CEvacuate the recovery hoses and manifold before opening the cylinder valve.
- DVent a small amount of refrigerant from the appliance through the hoses.
Show answer & explanationAnswer & explanation
Correct answer: C. Evacuate the recovery hoses and manifold before opening the cylinder valve.
Evacuating the recovery hoses and manifold removes any air present in them before recovery begins. This prevents non-condensable gases from being drawn into the recovery cylinder along with the refrigerant, maintaining refrigerant purity.
Why the other options are wrong
- A. Connecting quickly doesn't remove air already in the hoses; it only limits further ingress.
- B. Purging with nitrogen can introduce another non-condensable gas if not properly removed.
- D. Venting refrigerant is illegal and releases harmful substances into the atmosphere.
Preventing Air in Recovery
To prevent non-condensable gases (air) from entering the recovery cylinder, recovery hoses and the manifold gauge set should be evacuated to a vacuum before starting the refrigerant recovery process.
- Air is a non-condensable gas.
- Non-condensables reduce recovery efficiency.
- Contaminates recovered refrigerant.
- Evacuation removes air and moisture from lines.
Memory trick: Hoses clear, no air to fear!