Refrigerant Recovery Procedures & EPA Requirements

Overview

Refrigerant recovery is the mandatory process of removing refrigerant from HVAC systems and storing it in approved containers for reuse, recycling, or reclamation. EPA 608 regulations require certified technicians to recover refrigerant to specified vacuum levels before opening or disposing of equipment containing regulated refrigerants.

EPA 608 Recovery Requirements

Required Vacuum Levels:

Critical Compliance Points:

• Recovery must occur before opening sealed systems for maintenance or disposal
• Use only EPA-certified recovery equipment meeting ARI 740 standards
• Store recovered refrigerant in DOT-approved cylinders
• Maintain recovery equipment certification documentation
• Never intentionally vent refrigerants to atmosphere

Recovery Methods

System-Dependent Recovery

System-dependent recovery uses the system’s own compressor to push refrigerant into the recovery cylinder. This method is slower but requires minimal additional equipment.

Applications:

• Field service where minimal equipment transport is needed
• Systems with operational compressors
• When recovery machine is unavailable

Limitations:

• Achieves lower vacuum levels than self-contained equipment
• Cannot be used if system compressor is inoperative
• Slower recovery times

Self-Contained Recovery

Self-contained recovery machines use their own compressor and operate independently of the system being serviced. These machines achieve deeper vacuum levels and faster recovery.

Key Features:

• Oil-less compressors to prevent contamination
• Built-in filtration and separation
• High-efficiency recovery achieving required vacuum levels
• Portable design for field service

Recovery Equipment Setup

graph LR
    A[HVAC System<br/>High Pressure Side] -->|Liquid Line| B[Recovery Machine<br/>Inlet Valve]
    C[HVAC System<br/>Low Pressure Side] -->|Vapor Line| B
    B --> D[Compressor &<br/>Separator]
    D --> E[Filter Drier]
    E --> F[Condenser]
    F --> G[Outlet Valve]
    G -->|To Recovery<br/>Cylinder| H[DOT Approved<br/>Cylinder]
    H -->|Vapor Return| I[Cylinder Vapor<br/>Connection]
    I -.->|Optional Push-Pull| B

    style A fill:#e3f2fd
    style C fill:#e3f2fd
    style D fill:#fff3e0
    style H fill:#c8e6c9
    style B fill:#fff9c4
    style G fill:#fff9c4

Recovery Procedures

Vapor Recovery

Vapor recovery removes refrigerant in gaseous form from the low-pressure side of the system.

Procedure:

1. Connect recovery machine to system low-pressure service port
2. Connect recovery cylinder to machine outlet
3. Ensure cylinder has adequate capacity (80% max fill)
4. Open system and cylinder valves
5. Start recovery machine
6. Monitor manifold gauges until required vacuum is achieved
7. Close all valves and allow system to stand for 5 minutes
8. Check for pressure rise indicating trapped refrigerant

Recovery Rate: 1-3 lbs/min depending on equipment and system conditions

Liquid Recovery

Liquid recovery is significantly faster than vapor recovery and should be performed first when possible.

Procedure:

1. Connect recovery machine to system high-pressure liquid line
2. Position recovery cylinder below system level if possible
3. Open liquid service valve slowly to prevent flash gas
4. Recover liquid phase until flow stops or pressure equalizes
5. Switch to vapor recovery to complete the process
6. Continue to required vacuum level

Recovery Rate: 5-15 lbs/min for liquid phase

Push-Pull Recovery Method

Push-pull recovery uses system vapor pressure to push liquid into the recovery cylinder while the recovery machine pulls vapor from the cylinder top, significantly increasing recovery speed.

Setup:

1. Connect liquid line from system to recovery cylinder liquid valve
2. Connect recovery machine inlet to cylinder vapor valve
3. Connect recovery machine outlet back to system low side
4. Create continuous circulation loop

Advantages:

• Recovery rates up to 20 lbs/min
• Reduced recovery time on large systems
• More complete refrigerant removal

Recovery Equipment Types

Recovery Cylinder Requirements

DOT Certification:

• Use only DOT-approved cylinders (DOT 4BA or 4BW specification)
• Verify current hydrostatic test certification (5-year intervals)
• Never use disposable cylinders for recovery

Fill Limits:

• Maximum 80% liquid fill by weight
• Calculate using cylinder tare weight and refrigerant density
• Account for temperature effects on liquid expansion

Cylinder Identification:

• Gray body with yellow top for recovered refrigerant
• Label with refrigerant type
• Record date of recovery
• Never mix different refrigerants

Safety Considerations

Pressure Management:

• Never expose cylinders to temperatures above 125°F
• Use pressure relief valves on all connections
• Monitor cylinder pressure during recovery

Contamination Prevention:

• Use dedicated cylinders for each refrigerant type
• Install filter driers in recovery lines
• Inspect and change recovery machine oil regularly

Personal Protection:

• Wear safety glasses and gloves
• Work in ventilated areas
• Have emergency procedures for refrigerant exposure

Recovery Rate Optimization

Verification and Documentation

After completing recovery:

1. Allow system to stand for 5 minutes minimum
2. Verify vacuum holds without pressure rise
3. If pressure rises above required level, repeat recovery
4. Document refrigerant type, amount recovered, and final vacuum level
5. Label system as refrigerant-free if applicable
6. Record recovery cylinder identification and fill weight

Incomplete Recovery Indicators:

• Pressure rise during standing period
• System components still cold after recovery
• Recovery amount significantly less than system nameplate charge

Recovery procedures form the foundation of responsible refrigerant management and environmental compliance. Proper technique ensures regulatory compliance, maximizes refrigerant reuse, and protects both technicians and the environment from harmful emissions.