Options for Recharging Your Air Conditioner 

Motor vehicle air conditioners (MVACs) use refrigerants that can contribute to ozone layer depletion, climate change, or both. Stopping refrigerant leaks from MVACs helps protect the environment and improves your system’s cooling performance.

Vehicle owners generally have three options for addressing leaks and recharging refrigerant in their MVACs. These include:

• Topping off the system with refrigerant.
• Evacuating remaining refrigerant and recharging the system.
• Repairing or replacing leaky MVAC components and recharging the system.

Topping off or recharging a system should improve cooling the passenger compartment, but neither service permanently fixes refrigerant leaks. If done properly, repairing or replacing leaking MVAC components will provide longer lasting benefits.

Topping off Versus Evacuation and Recharge

A top off involves adding refrigerant to your MVAC. There is no way for technicians to determine how much refrigerant is in your MVAC system when you arrive at the shop, so they must guess how much refrigerant to charge into the system. They may undercharge or overcharge the system—both of which impair system performance.

Evacuation and recharge service involves removing the MVAC refrigerant, cleaning it using recycling equipment (to remove impurities), recharging it into the system, and adding new refrigerant to replace the amounts that have leaked out. Evacuation and recharge service allows technicians to add the precise amount of refrigerant recommended by the MVAC manufacturer.

Some technicians believe that evacuation and recharge is better for MVACs because the refrigerant is cleaned before being recharged. However, there is no reason to clean the refrigerant unless technicians open the system. Opening a system means any service, maintenance, or repair that could release ozone-depleting refrigerant. When technicians repair or replace system components, they should recycle the refrigerant.

Common Servicing Fees

Because technicians cannot determine how much refrigerant is in your MVAC, many charge a flat fee for top-off or evacuation and recharge services. The cost of both services usually includes a system performance check and may include a leak detection test. Topping off is less expensive than evacuation and recharge services.

As an alternative to the flat fee, shops might charge separate fees for labor and for the amount of refrigerant charged into the system (e.g., based on recommendations from the MVAC manufacturer).

Shops might also charge a refrigerant recycling fee to offset the cost of purchasing or maintaining the specialized equipment that they are required to use to recover and recycle refrigerant. Other shops keep recovered refrigerants to make up for the cost of the recycling equipment.

Technicians occasionally tell customers that any refrigerant that was in the vehicle cannot be returned due to federal regulations. No such federal regulation exists.

Finding System Leaks

Technicians can identify refrigerant leaks most of the time, especially if they are using an electronic leak detector certified under the Society of Automotive Engineers J1627 standard. However, technicians may have difficulty locating small leaks, even if using sophisticated leak detection equipment.

MVACs do not need to contain a full charge of refrigerant to locate a leak. A few ounces (about 10 percent of the normal charge) are sufficient to perform the leak check. In some cases, the technician will need to add refrigerant to the system to detect a leak.

Retrofitting MVACs for an Alternative Refrigerant

Retrofitting an MVAC involves converting the system to use an alternative refrigerant. In most cases, chlorofluorocarbonchlorofluorocarbonA compound consisting of chlorine, fluorine, and carbon. CFCs are very stable in the troposphere. They move to the stratosphere and are broken down by strong ultraviolet (UV) light, where they release chlorine atoms that then deplete the ozone layer. CFCs are commonly used as refrigerants, solvents, and foam blowing agents. The most common CFCs are CFC-11, CFC-12, CFC-113, CFC-114, and CFC-115. The ozone depletion potential (ODP) for each CFC is, respectively, 1, 1, 0.8, 1, and 0.6. A table of all ozone-depleting substances (http://www.epa.gov/ozone/science/ods/index.html) shows their ODPs, global warming potentials (GWPs), and CAS numbers. CFCs are numbered according to a standard scheme (http://www.epa.gov/ozone/geninfo/numbers.html). (CFC)-12 MVACs are retrofitted to operate using hydrofluorocarbonhydrofluorocarbonA compound consisting of hydrogen, fluorine, and carbon. The HFCs are a class of replacements for CFCs. Because they do not contain chlorine or bromine, they do not deplete the ozone layer. All HFCs have an ozone depletion potential of 0. Some HFCs have high GWPs. HFCs are numbered according to a standard scheme (http://www.epa.gov/ozone/geninfo/numbers.html). (HFC)-134a. A technician might recommend that you retrofit your system because CFC-12 is an ozone-depleting substance and is being phased out of use. As supplies of CFC-12 diminish, the price of this refrigerant is increasing. It may be more cost-effective to have your system retrofitted rather than to recharge or repair it for continued operation with CFC-12. Learn more about the transition to new MVAC refrigerants.

Leak Repair Requirements

EPA does not require leak repair before refrigerant is charged into a vehicle, but some states or localities may require the practice. EPA regulations also do not dictate any particular service, as long as the technicians are certified and use recycling equipment that meets EPA standards. For example, EPA does not require that MVACs be evacuated and recharged instead of topped off.