7.2 Type I Recovery Requirements
Key Takeaways
- Compressor running: 90% recovery or 4-inch vacuum; Not running: 80% recovery or 4-inch vacuum
- System-dependent (passive) recovery uses the appliance pressure or compressor; limited to 15 lbs
- Self-contained (active) recovery uses its own compressor — works regardless of appliance compressor status
- Heat the compressor with a blanket (never flame) and tap with rubber mallet to release trapped refrigerant
- Line tap valves are used to create access points on sealed small appliances
Recovery requirements for small appliances differ from those for larger systems. Understanding these specific requirements is essential for passing the Type I section of the EPA 608 exam.
Recovery Requirements Based on Compressor Status
The recovery requirements for Type I appliances depend on whether the appliance's compressor is functional:
| Compressor Status | Recovery Requirement |
|---|---|
| Compressor IS operating | Recover 90% of the nameplate charge, OR achieve a 4-inch Hg vacuum |
| Compressor is NOT operating | Recover 80% of the nameplate charge, OR achieve a 4-inch Hg vacuum |
Recovery Methods for Small Appliances
System-Dependent (Passive) Recovery
System-dependent recovery uses the appliance's own pressure or compressor to move refrigerant into the recovery container:
Method 1: Using the appliance compressor (if operational)
- Connect recovery equipment to the appliance process tube or service port
- Run the appliance compressor to push refrigerant into the recovery container
- Continue until 90% recovery or 4-inch vacuum is achieved
Method 2: Using system pressure (if compressor not operational)
- Connect recovery equipment to the appliance
- Allow refrigerant to migrate from the appliance to the recovery container based on pressure differential
- May require heating the appliance and/or cooling the recovery container
- Continue until 80% recovery or 4-inch vacuum is achieved
Self-Contained (Active) Recovery
Self-contained recovery uses a dedicated recovery machine with its own compressor:
- Connect the recovery machine to the appliance
- The recovery machine's compressor actively pulls refrigerant from the appliance
- Works regardless of whether the appliance compressor is functional
- Generally faster and more thorough than system-dependent methods
Accessing Refrigerant in Small Appliances
Small appliances often lack service valves, so technicians must create access points:
- Process tube: A small tube crimped or soldered shut during factory manufacturing — can be opened by piercing or cutting
- Line tap valve (piercing valve, saddle valve): Clamps onto the refrigerant line and pierces it to create an access point
- Schrader valve: If present, provides a standard service connection
Best practices:
- Install a line tap valve on the compressor process tube when possible
- After recovery, the pierced area must be sealed (soldered, brazed, or capped)
- Ensure the access point is on the correct side of the system for effective recovery
Releasing Trapped Refrigerant
When using passive recovery and the compressor is non-operational, refrigerant can become trapped in the compressor oil (refrigerant is miscible with oil). Techniques for releasing trapped refrigerant include:
- Apply heat to the compressor shell using a heating blanket or heat gun (NOT an open flame)
- Warming the oil reduces its ability to hold dissolved refrigerant
- The refrigerant vaporizes and can then be recovered
- Gently tap the compressor bottom with a rubber mallet
- Creates agitation that helps release dissolved refrigerant from the oil
- Allow additional time for refrigerant to migrate out of the oil
- Run the recovery machine in repeated short cycles to pull additional trapped refrigerant
Disposal of Small Appliances
Before disposing of any small appliance, the refrigerant MUST be recovered:
- The last person in the disposal chain is responsible for ensuring recovery was completed
- Scrap metal dealers and recyclers who accept refrigerant-containing appliances must have a Section 608 certified technician recover refrigerant, OR verify that recovery has already been completed
- Documentation of recovery should accompany the appliance through the disposal chain
For the Exam: Key numbers: 90% with compressor running, 80% with compressor not running, 4-inch Hg vacuum for both. Heating the compressor with a blanket (never an open flame) helps release trapped refrigerant from oil. System-dependent recovery is limited to 15 lbs.
What is the recovery requirement for a small appliance when the compressor IS operating?
How can a technician help release refrigerant trapped in compressor oil during passive recovery?
What is a "line tap valve" used for when servicing small appliances?