R134a systems operate at higher discharge-side pressures than R12, which can cause compressor seals to leak. Bottom line, R134a simply doesn't cool as well as R12. In addition, there was the lubricant issue. Because A/C compressors have moving parts, they require oil.
The experimental results show that for almost all test conditions the R·134a operates with greater COP and cooling capacity.
As the summer approaches, it's the right time to get your AC blowing ice-cold air. Back in the day, that might mean a recharge of Freon, also known as R12 refrigerant. 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.
R-134a has a very similar pressure-temperature relationship when compared to R-12 (See Figure 3). However, at the lower temperature, R-134a has a bit lower pressures than R-12. Also, at higher temperatures, such as 65°F, R-134a has a bit lower pressure when compared to R-12.
12a operates at lower head pressures and offers improved cooling properties and performance versus R134a and R12.
R1234yf, or HFO-1234yf, was introduced in response to environmental concerns over the continued use of HFC-134a. This newer refrigerant is a hydrofluoro olefin (HFO). It has a much lower global warming potential (GWP) compared to HFC-134a.
You're wondering if you can mix different refrigerants for your air conditioning system. The short-long-only answer is no, never. There are many reasons why it's impractical, illegal, and not economical for a homeowner to mix refrigerant types.
Limited quantities of reclaimed R-12 is still available for service of installed equipment. A wide variety of R-12 retrofit blends are available.
R-134a is not going to disappear in the same way as CFCs (chlorofluorocarbon) or R-12 did. R-12 was phased out in accordance with the Montreal Protocol in the 1990s, as it was found that the chlorine contained in the refrigerant was creating a hole in the ozone layer when it was vented into the atmosphere.
THERMODYNAMIC PERFORMANCE
Operating pressure for R152a is slightly lower (-10%) than R134a's at the same evapora- tion temperature rate. However, R152a has an equivalent cooling capacity (-1% compa- red to R134a) and might thus be used as a replacement in cooling systems operating with R134a.
Why Is R-134A Being Phased Out? When Is the Phaseout Expected to Conclude? Like a lot of '90s relics, R-134A has not aged well. It was known then that 1,1,1,2-tetrafluoroethane could potentially contribute to acid rain and that its ozone layer depletion potential was high.
The high heat transfer rates in the condenser and the evaporator due to absence of the oil also helps reduce the effects of this disadvantage. 2) R12 is CFC: R12 is the most widely used refrigerant, unfortunately it is the CFC and it has unusually high potential to cause the depletion of the ozone layer.
RS-24 also provides a long term solution to replacing R12 in most applications such as hermetic and semi-hermetic systems, domestic refrigerators, refrigerated transport, cold stores, cellar cooling, dairy chillers, vending machines and including mobile air conditioning.
R32 is the newest and most popular air conditioner refrigerant gas. This is because of its relatively high efficiency and low GWP (Global Warming Potential). R410A is also popular, but its higher GWP means that its more harmful to the environment.
R-134a is an HFC refrigerant and cannot be vented under the Venting Prohibition because it is a non-exempt substitute of CFCs and HCFCs. Question #8 Nitrogen can be used to pressurize or blow debris out of a system containing a half charge of refrigerant.
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.
R134a systems work at higher discharge-side pressures than R12 systems, which could lead to compressor seals leaks. Additionally, since R134a is composed of much smaller molecules, it has a greater chance of leaking from an R12 system.
This group of synthetic refrigerants is not subject to a ban on use. This means that installations using R134a, R407C and R410A can simply be refilled after 2030. However, there will be significantly less synthetic refrigerant available in the future due to production limitations.
While the production of new R12 is banned, it is not illegal to sell or use R12. In fact, many of the cylinders and cans of Freon R12 sold for decades throughout the United States are still around today.
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.
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.
R-22 refrigerant prices range from $90 to $250 per pound. Since you'll need between 6 and 12 pounds to refill a home AC, costs can reach between $660 and $2,400 for a refill of R-22 refrigerant. U.S.
Final answer: R-134a is the most commonly used refrigerant to replace R-12 in new household refrigerators, due to its ozone-friendly properties and suitability for refrigeration.
Here "a" is used to denote that it is an isomer. R134 and R134a have same chemical formula and atomic weight but different chemical structures. R134 has NBP of about -19 C whereas R134a has a NBP of about -26C. And don't use capital 'A' in R134a "A" denotes that the refrigerant is non-azeotropic.
In the figure, the notation such as R32 + R134a (90/10) indicates that R32 is a mixed refrigerant of 90 wt% and R134a is 10 wt%. As shown in FIG. 3, it can be seen that mixing R134a (or R1234yf) with R32 suppresses the discharge temperature.