They might say for instance, add 3-4 oz of oil to the compressor, 1 oz of oil for when you replace a drier, 2 oz oil for the evaporator and so on. |. Gnats & mosquitos will clog deep. Environmental Impact: When R134a escapes into the atmosphere, it contributes to global warming. There is more to check.The evaporator must be clean as well as the condensor - was this a smoker's car?You should check the water control valve for the heater core. I have some experience with auto a/c but not too much. #13. Minor adjustments to the expansion valve and other controls may be necessary for some plans. 3 ounces? R12 is heavier than R134a and has smaller molecules. It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. I could easily be over at least 2 - 3 ounces over on the oil. R-12 to R-134a Conversion. Debug the condensor (I am a computer nerd after all!)3. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. Be sure to test @ 1500 to 2000 engine rpm, and record the ambient temp as well. Not going to mess up your 'do, but you can feel it. Right now you know you have a bit too much, but with a CR4P compressor this is an insurance policy. July 3, 2022July 3, 2022. Its cylinders are colored white. It is mixed with the freon for the most part, and does accumulate in all components in small amounts. B. and feeds it through an expansion valve. The OEM spec is 2300 rpm @ 12.6v (engine stopped fully charged battery). I've got a ball valve I'm going to put in the coolant line before the coolant goes through the firewall to the core. They have no moving parts. The common problem when converting from R12 to R134a is lack of knowledge or equipment. With R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. Therefore, its most suitable for both commercial and domestic environments. The R134a compressor has a 1/8" step in on the high side port. If there is no pusher fan, and you have the room, put one in. It is perhaps possible to locate a unit with a company that purchases close out or distressed merchandise. It is also used in automotive car conditioning and the plastic industry. R-12 - yellow R-134a - light blue R-22 - green R-402A - light brown (sand) R-402B - olive R-404A - orange R-407C - medium brown R-410A - rose R-507 - teal J Originally Posted by goldNSX. . If you still find it difficult to use R134a in a home AC system, you can check out a comparison of R12 vs R134a fittings to know the refrigerant that best fits the AC system. You will be fine with a 134a-compatible TXV running R12. You can use this space to go into a little more detail about your company. and he synthesized R-134a in 1936, 5 years after R-12 was . 3) A TXV optimized for 134a will be ok with R12. When you add fluorescent tracer dye to with the refrigerant oil it helps to track down leaks that push oil out of the system. Lets take you through the advantages, disadvantages, and differences of these two refrigerants a detailed comparison including R12 vs R134a performance. These two refrigerants are the older types and are not used in newer refrigeration and air conditioning systems. Any suggestions, or do you need to know the hi/lo readings? difference between r12 and r134a expansion valve. -------------------------"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest." Vent temperatures slowly go down to around 50F with hi speed driving. Hmmmm. Its chemical symbol is CH2FCF3. R134a and water have the same abilities to change the state but R134a can do this more rapidly and at a much lower temperature than water. Besides, its technology has been tested and trusted. You do not need to replace the expansion valve in most cases. Well, I'm not sure it is 'fine' - it doesn't cool very well in 95F weather. Before landing on the debate of R134 vs R12 you should know that both R134a and R12 are AC refrigerants types used in refrigeration and air conditioning systems. We chose to use 5-6 ounces of oil to be on the safe side: 3-4 ounces for the compressor, 1 oz of oil for the drier and another ounce of oil for system losses. It runs between the condenser outlet, receiver/drier unit and expansion valve at the firewall. This leads me to labor over every small decision. Can I order a valve based on the original eaton number? _____ 2012 E350 2006 Callaway SC560 . R12 was once used in many air conditioning units as a refrigerant or cooling agent. Also, it can be used with all types of compressors. The AC usually does not work at all. Maybe a jerky locker.I cleaned the condensor with the off the shelf ac cleaner stuff from Home Depot that I used on my home evaporator. Additionally, R134a was introduced as a replacement for R22 and R12 in high and medium-temperature refrigeration systems like domestic and commercial chillers. _____ 2012 E350 2006 Callaway SC560 . Even though their common major function is to cool the system, they have many differences. These cheap kits usually have a few cans of R134a (either 12 ounce or 16 ounce), maybe an extra can of refrigerant oil, a few generic R134a charge port adapters and maybe some o-rings. It won't be optimal, though.On some/many valves, you can adjust them, but that might make matters worse unless you really know what you're doing (which I don't!).RegardsGeorge. About four or five years ago, I guy with an MB came here with the same problem, that tread was over six pages long. It didn't seem too dirty though - I don't think it is the problem, but I could be wrong. Then I'll put the ball valve in on the coolant and test it and see what we have. I know this is bad, etc, and deposits on the metal can act as insulators. And I already have so much time and money in this a/c project that I REFUSE to cut any corners as small as a TEV.It doesn't help that most people in the business (at least that I come in contact with, present company excluded, of course!) You will be fine with a 134a-compatible TXV running R12. Nice to use new gadgets! Existing technology: R134a has been in use in the refrigeration industry for very many years, and theres so much information about the safe use of the product. The cost of recharging the air conditioner is between $150 to $500. Please enter a password for your user account. Temp switch works the aux fan. The only difference I can imagine would be the recharge connection. It would make a big difference at idle ,in traffic!! Rxmechanic.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for website owners to earn advertising fees by advertising and linking to Amazon.com. Energy usage: R134a is less efficient in cooling compared to R12. GWP is a measurement of Greenhouse Gases and their effect on Global Warming. That is for the compressor, drier, expansion valve and condenser. Thanks so much Bohica - you've save me many more hours of fruitless speculation. R134a is NOT less efficient than R12 Actually R134a is more efficient. The pressure/temperature curves for R-1234yf and R-134a are very similar. by | Jun 21, 2022 | what is the most accurate latin translator | burlington iowa arrests | Jun 21, 2022 | what is the most accurate latin translator | burlington iowa arrests One of the differences between auto air conditioners that have been redesigned from R12 to R134a is that the condensers have gone from serpentine to pseudo-parallel. I dont know why the cost difference between compressors is so huge, though. maintain the A/C of older cars. You'll get marginally better performance out of the change as the expansion valve is matches the refrigerant characteristics. Thomas Jefferson, Thanks,OK, I'm starting to feel a little better about it. The original expansion valves work very well with R134a. R134a is the most widely accepted alternative automotive refrigerant used to replace R12. According to the thermodynamic characteristics, it is close to the R12 freon, however, it is 10-15% worse in terms of cooling capacity and is more fluid. Skin contact: If the R134a (liquid) comes in contact with your skin, it could cause a burn. You may need to adjust the valve in a bit to get desired superheat. I used a full can of evap cleaner. The compressors used by refrigeration plants to compress gas require oil to help lubricate its moving parts. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge. So if the TXV is OK, and the too much oil situation is not a big problem, then I wonder why the compressor is switching off after about 15 minutes of cooling? A/C Expansion Valve Replacement Cost. What is a T/C?4. The approval is very legal one, governed by the U.S. EPA. At the moment, the ac is acting up - will work fine for about 15 minutes and then slowly the vent temperatures rise until the compressor switches off. Blows pretty hard on full. There is NO reason to retrofit a vehicle to R-134a as long as the R-12 system is cooling properly and contains a normal charge of refrigerant. Your average garage that works on a/c on the side probably would not have this. Have a look in the FAQ Section, and look for "Fan clutches & testing them". sparkee said: Thanks for the Service Bulletin. Generally the system will be initially charged with approximately 80% to 85% of the original amount of R12, using R134a. For instance at 25 F the pressure of R-12 is 24.6 PSI and the pressure of R-134a is 22.1 PSI. Figure 2 shows the different phases and pressures the refrigerant . I think the way to go here is1. Hope this helps. I don't believe it is but I had a service guy tell me it needs to be done. If not, you just don't know unless a test is performed. You can also check the Aux fan in your case. Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. Replied by Rich928 on topic R12 or R134a. The Wikipedia explanation for expansions valves cited in Frank's thread says that the gas inside the bulb in the metering valve is the same as the refrigerant in the system. PaulJerky King -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. After the system has been tested out it should be checked for leaks. . -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a, Hi pdrayton- If you can remember the oil capacity that you found in all your research and post that, then bohica and others can have a better idea if you have too much; see if you can find that info! Then again, there are two different expansion valves. In more serious, it could result in cardiac irregularities or death. Some 1993 and older R12 systems aren't as 'compatible' as you'd think to switch over. Disconnect the two hose lines to the compressor, protect the ends from getting dirty. Electric fans do wear out. Operating Pressure/Temperature Differences The pressure/temperature curves for R-1234yf and R-134a are very similar. Plus, not releasing the chemical into the air is morally justifiable. R134a requires the use of synthetic oil! But some types of PAG do not mix well with the old residual R12 mineral oil left in the system components whereas ester does mix very well. The system has been previously converted to R-134a. The original rubber a/c hose lines in your car will leak out R12 through the hoses lining. R134a is called tetrafluoroethane (HFC). Very nice! How is the vent airflow?I would jumper the aux fan & check the performance. The oil used in R12 and R134a are different and not compatible. Remember, being aluminum, they lower the temps better, and do not pass off as much heat to the radiator, which then makes it's job easier and lowers underhood temps (besides lowering vent temps inside the car). The aux fan seems to be working fine - it switches on occassionally. B. Also, if you want to know what happens if you put R134a in an R12 system, you should first confirm if the R12 system can be replaced or if the refrigerants can be mixed. Swapping the components isnt a herculean task, but recharging the AC is a challenge. When the sensor detects the refrigerant leak the sniffers lights glow and the sniffer makes a noise. Reattach the hose lines using new R134a compatible o-rings, lightly lubricate with compressor oil. Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. When the temperature is reduced to-7C or below, the plants ability to cool the airdrops significantly. In practice this means that the car can overheat and the aux fan will stay off! Please enter the name by which you would like to log-in and be known on this site. It's best to determine on a case-by-case basis while monitoring system pressures and output air temperature. Safe but sorry! If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyers guides, and car and tools comparisons. Very interesting! The best replacement for R134a is R1234yf, while R12 refrigerant replacement was R134a. 1) Warm Air From Vents. Recovery & flushing is the only way out of an oil overcharge in your vehicle.B. Once you have replaced the OEM condensor with a PF unit, you will need to make custom hoses to mate with your OEM system. J.Harris said: Or if you want to do it like they do in Mexico you can use propane, it's an excellent refrigerant but highly flammable. R12, on the other hand, is called chlorofluorocarbon (CFC). If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? 30 deg is pretty coldSystems generally run between 40 and 43 deg. The higher the ambient temperature the higher the high side pressure. 34 in 70 series w/ R12 in 100+ Tucson, AZ summer heat w/ hd-t, w/ 13B-T is was unbearable about 31 at vent w/ R12. If you're getting a R134a compressor, might as well finish the job - replace the receiver/dryer, flush everything else, and convert to R134a anyhow. Just had knee surgery yesterday, so I"M not exactly hopping around too well. Generally, the new amount is 75-85% of the quantity advised by the manufacturer. Further production of R12 was banned in some developed countries by the Montreal Protocol because of its harsh effect on the ozone layer. If your a/c system is empty/low on refrigerant, if your system has a leak or if you need to open the system, then now is the time to decide which refrigerant you want to use. For instance you can evacuate FRIGC FR-12 into a refrigerant recovery bottle that has R134a in it or visa versa. George Bray on Wed August 31, 2005 5:03 PM I believe the optimum supercool setting will vary slightly between an expansion valve for an R12, as compared to R134a, system. This refers to BTU's (heat) moved per pound of refrigerant moved. Use strips of foam to couple the two heat exchangers if necessary.B. Even with proper fan operation, missing seals & air dams can effect condensor effeciency. Make sure to wear safety gloves, goggles, and shoes when theres a possibility of exposure to the chemical (R134a). 4) Inconsistent Airflow. Hopefully after you have read this entire page you will have enough information to determine which type of refrigerant is best for you. Replacement expansion valve for R134a or R12 A/C refrigerants, with O-ring connections. Is that why expansion valves are specific to R12 or R134A? With tube & fin condensors in MVAC applications there is never "too much" airflow. You either get a system that will function well with R1234yf or get any other type. Trinary Pressure Switch quantity. All fans must work at 100% of the OEM rating. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. The Wikipedia explanation for expansions valves cited in Frank's thread says that the gas inside the bulb in the metering valve is the same as the refrigerant in the system. Hot coolant migrates up through the core by convection (is that the word? Edited: Sat July 14, 2007 at 10:22 PM by fonebone. One of the differences between auto air conditioners that have been redesigned from R12 to R134a is that the condensers have gone from serpentine to pseudo-parallel. don't know enough about the subject to explain the choices.However, a few days ago I called the dealer to see about an OEM TEV and they said something that made me feel a little bit better; the same part number superceded every application back to the '60s, and that they couldn't do that without engineering signing off on it.Still, I would feel a lot better if I could see something written officially that compared the flow characteristics and performance of r12 and 134a TEVs are concluded that they were interchangeable in automotive applications.If someone knows of such a document I would sleep much better!Walt Edited: Mon September 12, 2005 at 8:13 PM by wamcneil. The typical scenario here is when the car owner buys an inexpensive retro-fit kit from the local auto parts store. A discussion of the relationship between valve capacities and superheat set-tings can be found in Bulletin 10-9. Inasmuch as R134a has a global warming potential thats over 1000 times more threatening than carbon dioxide, its better than R12. If you have a York, and it is equipped with service valves, you can check & adjust the oil level without discharging the system. look at the difference! Its chemical symbol is CCl2F2. Agram a retevis rt22 password i bastrop county district clerk records el material que oferim als nostres webs. Generally you follow the refrigerant flow moving from connection to connection, component to component, and you sniff the a/c vents to check for evaporator leaks as well. Its not that difficult but the procedures of evacuation, charging and testing should be done by a licensed a/c technician that is experienced with R134a and your particular car. R12, on the other hand, is called chlorofluorocarbon (CFC). Is the information not applicable to the old Pantera system? The problem with using an approved alternative refrigerants other than R134a is that when the system is serviced it requires certain types of fittings, labels and dedicated equipment. Should I do the test again with the the aux fan jumpered? It won't be optimal, though. R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. It is a known suspect that lets heat into the heat exchanger/core even when off because the mono-valve is on the exit side of the heater core. If the system was upgraded by a professional it should have an upgrade sticker. To prevent refrigerant loss you should consider replacing your old hose lines with barrier type hose. In large application systems, the vapor density of this refrigerant is usually high. Discussion in 'Technical' started by Jsarnold, May 25, 2012. We are an automotive mechanic blog that helps mechanics and car users to find the most recent and accurate technical and repair information for their cars. VerticalScope Inc. All Rights Reserved. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. The larger line at the expansion valve is the suction line. If the system was upgraded by a professional it should have an upgrade sticker. It was later found that R-134a had a very high Global Warming Potential, or GWP, number. I have a laser temp reader, and it says the temps going into the condensor are up to 160F - coming out it is always around 110 or so. Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). Heres R12 vs. R134a pressure chart. The system will be checked for gross leaks while under vacuum.
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