Leak Detection
& Record Keeping

Leak Detection Methods

Finding refrigerant leaks quickly protects the environment, saves refrigerant costs, and keeps systems running efficiently. Multiple detection methods exist - each with strengths and limitations.

1. Electronic Leak Detector

The most sensitive and commonly used method. Detects refrigerant concentration in the air using a heated sensor or infrared technology.

• Sensitivity: Can detect leaks as small as 0.1 oz per year
• Best practice: Move probe slowly at 1-2 inches per second; start at the lowest points (most refrigerants are heavier than air); check service ports, fittings, shaft seals first
• Limitation: Cannot identify exact leak location as precisely as UV dye; can false-positive near residual refrigerant from service work
• Important: Use a detector rated for the refrigerant - R-1234yf detectors must be HFO-specific

2. UV Fluorescent Dye

Fluorescent dye injected into the system circulates with refrigerant. Wherever refrigerant leaks, dye escapes and glows under UV (black) light.

• Advantages: Pinpoints exact leak location; permanent system monitoring - dye stays in system
• Procedure: Inject using a dye injector through low-side service port; operate system to circulate; inspect with UV lamp
• Limitation: System must operate to circulate dye; initial investment in UV lamp and dye injector
• SAE J2297: The standard for UV leak detection in automotive (MVAC) systems

3. Soap Bubble Solution

Soapy solution applied to suspected areas bubbles when refrigerant escapes. Only practical for large leaks at fittings and connections. Not sensitive enough for slow leaks.

4. Nitrogen Standing Pressure Test

After recovery, pressurize with dry nitrogen to verify repair quality before recharging. Never use oxygen - creates fire/explosion risk with refrigerant oil.

Common Leak Locations - Priority Order

1. Schrader valve cores (service ports) - very common, easy to check first
2. Flare fittings and brazed joints
3. Compressor shaft seal
4. Evaporator coil (especially from corrosion by formicary action)
5. Condenser coil (from physical damage or vibration fatigue)
6. Accumulator and filter-drier fittings

EPA Record Keeping Requirements

For systems containing 50 lbs or more of refrigerant, owners and technicians must maintain records of:

• Amount of refrigerant added to the system at each service
• Amount of refrigerant recovered from the system
• Dates of service
• Leak inspections performed
• Repair dates and verification

These records must be kept for 3 years and made available to EPA inspectors upon request.

Refrigerant Sales Records

Refrigerant distributors and retailers must maintain records of refrigerant sales including:

• Name and address of purchaser
• EPA certification number of the purchasing technician
• Date of sale
• Amount and type of refrigerant sold

These records must be kept for 3 years.