CFC-12, prominently known as Freon-12, was the industry-standard refrigerant in vehicle air conditioning systems for over three decades, until the mid-1990s. Recognized as both an ozone-depleting substance and a potent greenhouse gas, its use in new vehicles has been prohibited since 1994. However, numerous older vehicles originally designed for CFC-12 may still be in operation. This article serves as a guide for both automotive technicians preparing for Cfc R12 system retrofits and vehicle owners contemplating upgrading their CFC-12 AC system to a more environmentally friendly, non-ozone-depleting refrigerant.
The EPA’s SNAP Program and CFC R12 Refrigerant Alternatives
The Environmental Protection Agency (EPA) established the Significant New Alternatives Policy (SNAP) program to facilitate a smooth transition to safer alternatives that minimize risks to both human health and the environment. The SNAP program rigorously evaluates and either approves or prohibits alternative refrigerants.
Within the context of Motor Vehicle Air Conditioning (MVAC) systems, when a refrigerant substitute receives SNAP approval, it is categorized as acceptable, often with specific use conditions. This approval can be for implementation in new vehicles, for retrofitting existing MVAC systems, or both. It’s important to note that some refrigerants are approved exclusively for new vehicles and are not authorized for retrofit applications, and vice versa. For systems originally using CFC-12 refrigerant, HFC-134a, alongside various HCFC and HFC refrigerant blends, are approved by SNAP as acceptable retrofit options.
Retrofit Use Conditions for CFC R12 Replacements
SNAP has deemed HFC-134a and several HCFC and HFC blends as acceptable retrofit refrigerants for CFC R12 systems, provided certain use conditions are met. These conditions are uniformly applied across all approved MVAC retrofit refrigerants to ensure safety and environmental protection.
Unique Fittings: Preventing Refrigerant Cross-Contamination
A critical use condition mandated by SNAP is the implementation of unique fittings for each approved refrigerant. This measure is designed to prevent the accidental mixing of different refrigerant types. These unique fittings are essential components at connection points throughout the system, including the vehicle itself, refrigerant recovery and recycling equipment, can taps, charging equipment, and refrigerant containers. Crucially, adapters to convert fittings should never be used, as this defeats the purpose of preventing cross-contamination.
Unique fittings play a vital role in safeguarding consumers by ensuring system integrity and preventing the use of incorrect refrigerants. They also maintain the purity of each refrigerant type, which is essential for optimal AC system performance and longevity. Detailed information on MVAC refrigerant unique fittings, including sizes and label colors, can be found in resources like “Fitting Sizes and Label Colors for Motor Vehicle Refrigerants.”
Labels: Clearly Identifying Retrofitted Refrigerant Information
When retrofitting a CFC R12 system, technicians are required to remove or completely obscure the original CFC-12 label. A new, detailed label must then be applied, providing comprehensive information about the alternative refrigerant used. EPA resources, such as the fact sheet “Fitting Sizes and Label Colors for Motor Vehicle Refrigerants,” specify the designated label colors for each retrofit refrigerant. The new label must include the following critical details:
- Name and address of the technician and the company that performed the retrofit service.
- Date of the retrofit procedure.
- Trade name, charge amount, and, where applicable, the ASHRAE numerical designation of the replacement refrigerant.
- Type, manufacturer, and amount of lubricant used in the system with the new refrigerant.
- If the refrigerant is or contains any ozone-depleting substance, the label must clearly state “ozone depleter.”
- For refrigerants classified as flammable according to ASTM E681 standards, the label must include the warning: “This refrigerant is FLAMMABLE. Take appropriate precautions.”
- The label must be of sufficient size for easy readability and be made of a permanent material to withstand engine compartment conditions.
- The background color of the label must be unique to the specific refrigerant used.
- The label must be affixed directly over the existing CFC-12 information on the system, in a location that is not typically replaced during routine vehicle maintenance or repairs.
- Any pre-existing information related to the original CFC-12 refrigerant that cannot be covered by the new label must be rendered permanently unreadable to avoid confusion.
Proper Removal of Original CFC R12 Refrigerant
Prior to charging the system with the new, alternative refrigerant, it is mandatory to evacuate all of the original CFC-12 refrigerant. This process must be performed using EPA-approved recovery-only or recovery and recycling equipment. This step is crucial to prevent the contamination of the new refrigerant with residual CFC-12, ensuring optimal system performance and preventing potential damage.
This requirement, along with other necessary system modifications described, emphasizes that no alternative refrigerant can be considered a simple “drop-in” replacement for CFC-12. The EPA explicitly avoids using the term “drop-in” to describe any approved retrofit refrigerant, highlighting the need for a comprehensive retrofit procedure.
Installation of a Compressor Shutoff Switch for System Safety
Certain older AC systems equipped with CFC R12 include a pressure relief device designed to vent refrigerant into the atmosphere in the event of excessively high system pressures. When retrofitting such a system with a new refrigerant, it is imperative that technicians install a high-pressure shutoff switch. This safety switch is designed to prevent the compressor from building pressure to a point where the refrigerant could be vented, thereby protecting the system and the environment.
Upgrading to Barrier Hoses for Refrigerant Compatibility
HCFC-22, a component found in some approved refrigerant blends, has a tendency to permeate through traditional CFC-12 hoses. Consequently, when retrofitting to these HCFC-containing blends, it is necessary to replace the original hoses with less permeable “barrier” hoses. This upgrade prevents refrigerant leakage, maintains system charge, and ensures the longevity and efficiency of the retrofitted AC system.
