R-12 is no longer used or produced in many countries and remaining quantities have skyrocketed in price. Thus, when the system is running, condensing the CO2 is not a problem. I think so. Therefore, the R12 refrigerant is illegal, and emitting it is illegal. This would be a custom install, there is no "drop-in" condensor upgrade for that car.Check for proper fan operation, and clean the air path on both the condensor & radiator. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores. The most common influences which effect the capability of R134a to perform well are the condenser, in some cases the the superheat setting of the expansion valve or the amount of R134a. There are three different refrigerants officially sanctioned by the EPA for automotive usage: r-12, r-. Even with proper fan operation, missing seals & air dams can effect condensor effeciency. However, it was found to be a very bad gas for the environment. Are r12 and r134 fittings different? Inasmuch as R134a has a global warming potential thats over 1000 times more threatening than carbon dioxide, its better than R12. Edited: Tue July 17, 2007 at 3:25 AM by bohica2xo, I believe there is only one switch - the refrigerant switch. The system has been previously converted to R-134a. R-12 expansion valves can be re-used, but will not be as efficient as R-134a specific ones because of the slightly different pressure specs of R-12 vs. R-134a. On the other hand, R12 has a global warming potential of 10,910. R12 is heavier than R134a and has smaller molecules. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . Its chemical symbol is CCl2F2. But, if your old compressor has lock-up or if your current expansion valve is not functional it would wise to replace the expansion valve with a valve designed for R134a. For example, if your system originally had 36 ounces of R12 then you multiply that by .80 and you have 29 ounce of R134a. I am ordering new parts, and planning to convert my system to R-134a. The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. It's actually a reaction with chlorine in the mineral oil that may have been absorbed and leftover from the old R-12. So the steps involved are cleaning out the old oil, replacing all the O-rings, replacing the dryer, replacing the expansion valve, and converting the high and low side connectors from Schrader to quick connect valves. I remember I had the wrong seals and it leaked some oil, so I put some more in.Bohica - I tested the pressures. 5. R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. The newer valves and switches will work with both refrigerants. R12 is simply too expensive for a 25+ year old A/C system. ESP when a compressor has frozen. Besides, its technology has been tested and trusted. Vent temperatures slowly go down to around 50F with hi speed driving. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. Is there a difference in the expansion valve for R12 as opposed to R-134a? This is 11F off the FSM performance graph - vent should be around 50F. The first vehicle that used the R1234yf refrigerant was the 2013 Cadillac XTS. We mention using ester type refrigerant oil. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . Also, would a genuine R12 TXV be better, or is it too marginal to worry about?I think I should do the FSM test for performance - they have a graph with ambient temp and a/c temp. The evap is hard to get at. This can be very very expensive. If you find any of these conditions you will want to liquid flush (with dedicated AC flush solution) all the lines, condensers, evaporator (remove the expansion valve) before you proceed further. This refers to BTU's (heat) moved per pound of refrigerant moved. That way I will have reduced the oil by about 1/3 (assuming the oil is mixed evenly through the system). A good T/C, clamped to the line & insulated gives a repeatable measurement of the tube. We consider the the various types alternative refrigerants that are illegal or not approved to be in two sectors: non-flammables and flammables. Is there a graph? These two refrigerants are the older types and are not used in newer refrigeration and air conditioning systems. I don't have the FSM matrix handy for that 123.123, but a 123.133 shows a test rpm of 2,000 - and vent temps between 54f & 66f at 91f to 95f ambient. In most cases, the systems used have varied components, designs, and service ports. 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. They should be able to keep you comfortable on a long trip, but don't expect vent frost in 3 minutes or lesss.2) Too much oil can reduce cooling capacity, and the effect is not linear. Thus, when the system is running, condensing the CO2 is not a problem. The original expansion valves work very well with R134a. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. The cure is to use the newer R134a compressors is sealing washers that are different thickness. But, what is considered a good temperature differential across the condensor? To ensure the right charge, you must fill the new system with between 75 and 85% of the factory-set capacity for optimal cooling. With that said, I would source the TXV from another source such as NAPA just to avoid any problems. Hence, the effect of R12 on global warming is up to 10,000 times higher than carbon dioxide. It will work and there will be very little, in any difference in performance.As Chick stated, the difference is only the gas used in the sensor tube. Most importantly, the oil used in the plant must always be compatible with the refrigerant used. Edited: Sat July 14, 2007 at 10:22 PM by fonebone. Are you sure you have an R4? Replied by Rich928 on topic R12 or R134a. Super heats are so close, it should not be a major concern.-------------------------The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government. _____ 2012 E350 2006 Callaway SC560 . Hopefully after you have read this entire page you will have enough information to determine which type of refrigerant is best for you. Miscibility with oil: R12 can be mixed with the compressor oil no matter the operating condition. You may need to adjust the valve in a bit to get desired superheat. I have some experience with auto a/c but not too much. R1234yf is more environmentally friendly and has a global warming potential of 4. gital control scheme. You either get a system that will function well with R1234yf or get any other type. Very nice! The car never overheats, if that has any import. 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. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge. This means that it has a high potential of causing depletion to the ozone layer. With the knowledge of the differences, youll be able to draw a comparison between R12 vs R134a efficiency. Autor de l'entrada Per ; Data de l'entrada calexico west port of entry hours; 12 month libor rate 2021 a difference between r12 and r134a expansion valve a difference between r12 and r134a expansion valve Ask Our Pros-Owner Assistance - NO DIY advice will be given. (You must log in or sign up to reply here. It is usually sold under the brand name, Freon 12. I had a 1991 BMW switched to 134a by just changing the low pressure charging valve, flushing and refilling with 134 (maybe with 10% . Usually, mechanics charge around $200 for conversion. That is for the compressor, drier, expansion valve and condenser. 1.5 ounces - hmmm. R134a is called tetrafluoroethane (HFC). In this study, without the need for major modifications to the bus air conditioner, the variation of the ejector dimensions according to different parameters has been investigated in the case of using the R1234yf, R1234ze(E), or R600a refrigerants, which may be a substitute for R134a as a refrigerant due to . 4) Repeat step 2, making sure it will fit. Where would I get some basic info on it, I know nothing about it. Back in that era, my business associates drove those things, brand new, and maybe I should take my Cadillac instead, no they wouldn't be caught dead in a Caddy, people of our esteem should be driving an MB. I've straightened the fans I can and sprayed simple green on it, let it soak then hosed it down well. 2001-2023 Griffiths Technical Inc. All Rights Reserved. You'll get marginally better performance out of the change as the expansion valve is matches the refrigerant characteristics. This is a great space to write long text about your company and your services. Therefore, the higher the factor of the chemical (compound), the greater its effect on global warming. If your cars system has a sufficient condenser design and air flow to expel the greater amount of heat extracted by R134a, then by all means you should convert over when the time comes. I dont know why the cost difference between compressors is so huge, though. The crossover point is approximately at 64F. With R134a you do not rely on the site glass. In the automotive world, the replacement for R12 was R134a. Moreso, it had been banned. Pray I can let some oil out of the compressor without losing my precious R12. This implies that the discharge pressure of the compressor should be moderate so it can produce the refrigerants condensation in the condenser at the atmospheric temperature. R134a has an ozone depletion potential of 0, implying that it has a slight effect on the ozone layer. Whenever its exposed to the environment, it changes to a gas. Still, I have some simple green, so may as well give it a go. american sniper longest shot; how to adjust sunsetter awning arms; pastor jeremy roberts texas. It runs between the condenser outlet, receiver/drier unit and expansion valve at the firewall. Compatible with multiple applications: The major reason for the introduction of R134a was to replace R12, so it functions perfectly in the same range of applications like rotary, screw, and centrifugal compressors for air conditioning and refrigeration. So I probably put the highest suggested amount in to be safe. Took me a while to figure that one out, and how to say that. Expansion Valves Catalog E-1, July 2012. The butylcellusolve or the citrus solvent will dissolve the carcass in a few minutes. The substitute that we used for R-12 was the new HFC called R-134a. It is mixed with the freon for the most part, and does accumulate in all components in small amounts. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. R12 can move more heat than r134 so when it isn't very hot and the system isn't maxed out you wont be able to tell the difference but when its 110 out and the inside is 140 R12 will cool the cabin temp faster. Looks like a couple of things happening here1) 80's vintage Eurocars were not "meat lockers". Plus, not releasing the chemical into the air is morally justifiable. -------------------------Just another brick in the wallHad a little mule I fed him castor oil and every time he jumped the fence he fertilized the soil, The older expansion valves were filled with the refrigerant they were used with, the replacement valves (today) are filled with a different chemical to work with both refrigerants..Hope this helps-------------------------ChickEmail: Chick---------------------------------------------Freedoms just another word for nothing left to lose, I believe the optimum supercool setting will vary slightly between an expansion valve for an R12, as compared to R134a, system. The good thing is that after you convert to R134 you can top off the system easily and cheaply. Low refrigerating effect per pound: In comparison to other refrigerants, the refrigerating effect of R12 per pound is low. For instance at 25 F the pressure of R-12 is 24.6 PSI and the pressure of R-134a is 22.1 PSI. The difference really shows up on the high side. Using R134a requires that Polyolester (POE) lubricant must be used in the compressor. It has already been clearly stated that R12 is a chemical that damages the earths ozone layer and shouldnt be released into the environment no matter the circumstance. R12 contains a chemical called chlorine that destroys the ozone layer, thereby causing potential environmental risk. It was later found that R-134a had a very high Global Warming Potential, or GWP, number. The old compressor used R12 and the new unit will be R134a. For those of you who are considering what the cost is for R12 you can think of it this way: Dont go out to dinner this weekend. CONCLUSIONS The differences in the theoretical C.O.P.H calculated for R12 and R134a are consistent with values quoted in the literature. Figure 2 shows the different phases and pressures the refrigerant . This may be the source of your oil confusion. Statisicaly your friend was lucky. Make sure to get the R12 EXP valve if that is the way you go. Gain access to our free AOP (Ask a Professional) Section to get real answers for your questions. ambulance tailgate conversion I'm also thinking maybe I should go to R134 - it might work better with the right amount of oil and the correct expansion valve. If not, you just don't know unless a test is performed. R134a was selected as a replacement refrigerant for R12 because R12 contains chlorine and has a major effect to ozone layer depletion. Yes it will work with either Refrigerant! The compressors used by refrigeration plants to compress gas require oil to help lubricate its moving parts. The #1 question asked by NEW MEMBERS. So if you car has a large amount of rubber hose, such as a 40 feet with the 911, then you will be re-charging the system often and that is expensive no matter which refrigerant you use. The only material difference between automotive A/C and a window A/C unit or refrigerator is that in the home application, the components are all inside the same rectangular box, but in the automotive application, the components are distributed throughout the car. Some compressor manufacturers or OEMs suggest PAG type oil for R134a. Helical and Serpentine coils. By: james smith underoath; Comments: 0 . Condensers designed to release greater amounts of heat help to expel the greater amount of heat which R134a removes from the cars interior. #4. Automotive Replacement Expansion Valves & Parts; Industrial & Scientific; Customer Reviews. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. Hot coolant migrates up through the core by convection (is that the word? . In a car ac, using this type of freon 20 years ago was difficult. Carefully study the chart and compare the following: To a large extent, the choice is up to you. R134a requires the use of synthetic oil! A thermostatic expansion valve (TXV) (see Figure 1) is a refrigeration and air conditioning throttling device that controls the amount of refrigerant liquid injected into a system's evaporatorbased on the evaporator outlet temperature and pressurecalled the superheat. The sticker typically has a place to note the amount of refrigerant used, the type of oil and amount of oil, the technicians sign off or name and the date of the conversion. After the initial charge the system is then tweeked : you determine the optimum amount of refrigerant to match your system by monitoring the a/c outlet vent temperature and the high side pressure as you add or remove refrigerant. Depending on which circuit diagram fits your car (cough, no vin list exists) you have either one or two switches controlling the aux fan. Consider using the newer valve, even with 134a stamped on the valve. how to get to disney springs from boardwalk / bb dakota plaid jacket canada / difference between r12 and r134a expansion valve. . The non-flammables can have R22 type gas which is not compatible with most rubber hoses or they have gases that contribute to global warming. Some 1993 and older R12 systems aren't as 'compatible' as you'd think to switch over. In short, NO! Trinary Pressure Switch quantity. I'm having the same concern. look at the difference! An extra half ounce? And no, you cannot "drain' excess oil out. R134a. What is usually sniffed are all the connections in the system: hoses and compressor, condenser, drier, expansion valve and evaporator fittings. I don't believe it is but I had a service guy tell me it needs to be done. 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. I'm thinking I might have put too much oil in the system - everywhere i read had a different amount - the manufacturer of the compressor, the MB factory service manual, online forums. Nice to use new gadgets! What is a good differential? The catalytic converter is an essential component of your car's emission system that helps save the environment from harmful emissions. Very interesting! It is a haloalkane and hydrofluorocarbon (HFC) refrigerant that has thermodynamic properties, potential global warming for one hundred years, and insignificant ozone depletion. and he synthesized R-134a in 1936, 5 years after R-12 was . Large temperature difference between expansion valve inlet and outlet oReplace expansion valve Air . Not osmosis, but you know what I mean). The global warming potential of R134a is 1430. That would be the "black death" syndrome. Theres no doubt that R12 refrigerant is one of the first compounds manufactured for the air conditioning and refrigeration world, but it had to be banned. Replace the drier with a drier that has a desiccant that is R134a compatible, use new R134a o-rings. Big . 4 Stars & Up & Up; 3 Stars & Up & Up; 2 Stars & Up . If you have a York, and it is equipped with service valves, you can check & adjust the oil level without discharging the system. 3) A TXV optimized for 134a will be ok with R12. At the time I thought nothing of it, but now I am thinking maybe that is contributing to the system not working as well as it could. Talk about what services you provide. 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. Electric fans do wear out. 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? El maig de 2016, un grup damics van crear un lloc web deOne Piece amb lobjectiu doferir la srie doblada en catal de forma gratuta i crear una comunitat que inclogus informaci, notcies i ms. I used a full can of evap cleaner. You will be fine with a 134a-compatible TXV running R12. Though - the valve for a 1991 says R12 on it, and for a 1994, it says R-134a. The condensor airflow drops off as the fan clutch dies slowly. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? 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. How is 1234yf different from . I'm going to check the condensor is way clean too. How an A/C Expansion Valve Works. Any ideas from the info above? Is there a difference between a R134a expansion valve and an R12 TXV? Unfortunately, the R12 refrigerant doesnt always blow cold air. This is the part that controls the system pressures. 5) A/C System Failure. I had a pair on my SAAB that seemed ok - but new ones ran 20% faster!Your best clue to airflow issues is a 60 mph test. Right now you know you have a bit too much, but with a CR4P compressor this is an insurance policy. Be sure to test @ 1500 to 2000 engine rpm, and record the ambient temp as well. R12, on the other hand, is called chlorofluorocarbon (CFC). Refrigerators generally utilize R22, R32, or 410A-based coolants as their cooling agent. I'll put the relay on for that. Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. Heres R12 vs. R134a pressure chart. There are R134a specific valves that operate at a slightly different pressure, but not for any "old" automotive application that I'm aware of. I would suggest you do stay away from R-134a since with the hot gas bypass of your system (if it is to be just as the original) extremes of temperature and pressure will be very hard on your compressor and the rest of the system. In practice this means that the car can overheat and the aux fan will stay off! The oil is spread all over your system when it is at rest. All fans must work at 100% of the OEM rating. At 40, it is 35psi, which is a difference of 8.9psi. A. Pressure/temperature plot of R134a vs. R12 is shown in figure 1. Given two identical vehicles, each with the same weighted amount of refrigerant, the vehicle with the R134a has the capability to remove more heat (measured in btus) from the vehicle than the same type of vehicle using the same amount of R12. Does it matter - assuming both are new & uncontaminated? Lets take you through the advantages, disadvantages, and differences of these two refrigerants a detailed comparison including R12 vs R134a performance.
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