But Freon was shown to deplete the earth's vital ozone layer. So carmakers were mandated to stop using R12 after the 1994 model year. One current replacement refrigerant is R134a, which serves the same purpose as Freon but is less harmful to the environment.
For many years, R12 was the automotive refrigerant standard. It was effective and cheap. However, scientists quickly discovered its sinister secret: It was partially responsible for the rapidly-depleting ozone layer. In 1994, it was banned from all new cars sold in the US.
INHALATION: R-12 is low in acute toxicity in animals even at concentrations of 5% (50,000 ppm). However, when oxygen levels in air are reduced to 12-14% by displacement, symptoms of asphyxiation, loss of coordination, increased pulse rate and deeper respiration will occur.
The other two refrigerants that are considered good replacements for R12 are R-401a and R-401b. R-401A is the mixture by weight of 53% of R-22, 13% R-152a and 34% R-124. It is good replacement for R12 in the applications where the evaporator temperature is -23 degree C and above.
As previously stated, R12 systems usually use mineral oil, which is incompatible with R134a. When R134a comes into contact with mineral oil, it can hinder the oil from returning to the compressor, or possibly reduce heat transfer.
Limited quantities of reclaimed R-12 is still available for service of installed equipment. A wide variety of R-12 retrofit blends are available.
These charts show the conversion values from the original R12 charge to the new R134a charge. The conversion is determined by multiplying the R12 charge value by . 75 (R12 charge x . 75 = R134a charge).
The Duracool 12a is used to replace the R12 and R134a gases and owes its success to its ecological qualities. It is an hydrocarbon gas with zero impact on the ozone layer. It requires only 35% of the load weight of the R12 and 40% of that of the 134a.
The different types of refrigerants are not meant to be mixed. The refrigerant charge must be optimized by using the refrigerant's respective pressure-temperature chart.
The experimental results show that for almost all test conditions the R·134a operates with greater COP and cooling capacity.
In compliance with the Montreal Protocol, its manufacture was banned in developed countries (non-article 5 countries) in 1996, and in developing countries (Article 5 countries) in 2010 out of concerns about its damaging effect on the ozone layer.
R134a is not an ozone-destroying agent, but it is a greenhouse gas, and is illegal to vent as well.
That's because refrigerant simply does not go bad or expire. As long as the cylinder or can is fully sealed (no leaks) and the valve is not open or broken, refrigerant will last in its container indefinitely. If intact, the can/cylinder is a sealed unit and will not deplete or leak refrigerant.
You can easily add new refrigerant using a supply hose (including a pressure gauge) and an adequate supply of refrigerant (or a complete recharge kit).
Or, if you'd like to tackle the job yourself, AutoZone has all the tools and refrigerant to service your R-134A or R-12 vehicle.
A very frequent question people ask us is whether it is legal to sell R12 refrigerant. The answer is yes – but not to just anybody. It is only possible to sell Freon, R-12 or any other CFC to EPA-certified technicians, like the experts at Refrigerant Finders.
Freon™ 409A carries an ASHRAE A1 safety classification and blends R-22, R-142b, and R-124. It can be used in medium- and low-temperature positive displacement equipment. Used as a retrofit for R-12 in stationary positive displacement air-conditioning (AC) and refrigeration systems, Freon™ 409A works in: Walk-in coolers.
In 2010, the U.S. stopped the sale of newly manufactured residential air conditioning units and heat pumps that use R-22 because of its particularly harmful impact on the ozone layer when released into the air. On January 1, 2020, the U.S. Environmental Protection Agency (EPA) banned the production and import of R-22.
The pressure can become high enough for parts of the system to rupture. At the very least, leaks will occur.
In conclusion folks R-12 Freon was banned due to the damage that it caused to the Ozone layer.
HFC-134a is the alternative refrigerant of choice to replace CFC-12 in many medium- and high-temperature stationary refrigeration and air conditioning applications. It has also replaced R-12 in automotive air conditioning applications. However, R-134a is not a direct drop-in refrigerant for R-12.
Propane makes a good substitute for R12 with very little modifications.
As a general rule, 80-85% of the R-12 fill is the amount to use for R-134a. However, that must be balanced against the high and low pressure readings you get as you fill. Hopefully when you converted you used ester oil and not PAG oil, or else you are likely to get clogs and ruin the compressor.
Attach a piece of heater hose to one fitting of the evaporator and place the other end in an empty bucket. Use the flushing tool to blast the solution into the other fitting, allowing the contaminants to drain into the bucket. Failing to secure the hose can cause spills or incomplete flushing.
You have to sweep the system components to remove any minerial oil, change the drier, add ester oil to the compressor and individual components, pull a vacuum to remove any air and moisture from the system, and recharge it with R134a. And after you do all that, the system might not perform as well as it did with R12.