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.
However, R134a is not a 'drop-in' replacement for R12 because there is a need to change the compressor lubricant and expansion valve. Changing over from R12 to R134a can therefore be an ex-pensive and time consuming procedure.
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.
The best drop in replacement for R12 is R152a, which is most easily bought as computer duster (seriously). It has very similar psychrometric performance to R12 so heat exchanger sizing is the same, pressure switches still work as intended, and system performance is the same as stock when everything is working well.
Drop-in and long-term R12 replacement
RS-24 is an easy-to-use Drop-in replacement for R12, There is no need to change the existing lubricant in the system, thereby avoiding a costly retrofit.
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 results exhibited that the most suitable refrigerants as R134a drop-in substitutes are R1234yf, R152a, R450A, and R513A. The pure R1234ze and its mixtures are not suitable drop-in replacements of R134a but can be a good alternative to R134a only in new refrigeration systems.
An HCFC Replacement Refrigerant for R-12
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.
R12 to R134a Charge Conversion Formula (pounds only)
Take the R12 charge specification and multiply it by 0.9. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge.
The refrigerant that is commonly used as a direct drop-in replacement for R-12 in retrofitting mobile air conditioning systems is R-134a (HFC-134a).
The evaporator exit superheat was maintained constant at 13.5 F (7.5"C) for all tests. The experimental results show that for almost all test conditions the R·134a operates with greater COP and cooling capacity.
More than 100 countries have signed on to the Montreal Protocol which banned R12 – undoubtedly representing the vast majority of refrigerant usage globally.
While it can no longer be manufactured, there is a surprising amount of Freon still available as new old stock (NOS).
The AIM Act is a Federal nationwide rule phasing out the use of global warming materials. As part of that effort, EPA is now banning the use of 134a in aerosol products as of 1/1/2025. There are excepted products that are allowed to use 134a until 1/1/2028.
With the scientific approach to reduce the global warming potential (GWP) of the refrigerant R-134A (i.e. 1430), the refrigerant R-513A with GWP of 631 is the drop-in replacement.
Still, the answer is an emphatic, “No.” Not only would a retrofit of this type negate the environmental benefits of R-1234yf, but it would also be a violation of Federal Law under Section 203 of the Clean Air Act: “tampering” with a vehicle's emissions control device.
RS-24 is a “Drop-in” alternative for R12 which also provides a long term solution at the same time. It provides, therefore, a one change solution to the replacement of R12 at minimal expense.
With the phase-out of R12 (1st January 1996) many compromises have to retrofit to R134a. No direct “drop-in” replacement is available, even alternatives such as ternary blends require the replacement of components such as “O” rings on some systems, filter dryers or accumulators.
The same two refrigerants and 19 others are being listed as unacceptable in new cold storage warehouses from January 1, 2023. The banning of R134a, along with 27 other refrigerants, in new domestic refrigerators and freezers from January 1, 2021, is expected to open the way for the use of hydrocarbon refrigerants.
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.
Automotive service technicians depend on Freon™ 134a (R-134a) refrigerant, a non-ozone depleting hydrofluorocarbon (HFC) replacement for R-12. Freon™ 134a is the standard in many mobile air conditioning (AC) units, and also replaces R-12 in: Commercial stationary refrigeration systems.
The GWP for R-134a refrigerant is 1,430, making it 1,430 times more harmful than carbon dioxide when released into the atmosphere. There are three refrigerants that can be used to replace R-134a: R-1234yf, R-152a, and R-744.
The cooling capacity of R1234yf used as a drop-in replacement in a R134a refrigerant facility is about 9% lower than that presented by R134a in the test range. This difference in the values of cooling capacity obtained with both refrigerants decreases when the condensing temperature increases and when an IHX is used.
According to its manufacturer, Chemours, use of R-1234yf has grown so much since the refrigerant replaced the long-established R-134a that it's now used in 95% of new cars sold in the U.S. An estimated 220 million cars on global roads are also using it.