and he synthesized R-134a in 1936, 5 years after R-12 was . -------------------------"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." However, R134a is better than R12. UNDERSTANDING A/C Everything You Need To Know - Classic Auto Air On this website we are addressing only R134a and not other suggested drop in replacements. This is because R134a. If you have a York, and it is equipped with service valves, you can check & adjust the oil level without discharging the system. Concentration level: The R134a vapor dilutes the oxygen concentration in the air to a low level, thereby causing harm. I'm curiousSo there is work to do, ie performance should be able to be improved. It is made up of carbon, hydrogen, and fluorine. difference between r12 and r134a expansion valve. The aux fan seems to be working fine - it switches on occassionally. 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. A/C receiver difference between R12 and R134a? difference between r12 and r134a expansion valve. R12 contains a chemical called chlorine that destroys the ozone layer, thereby causing potential environmental risk. 3) A TXV optimized for 134a will be ok with R12. I'm doing one thing at a time so I know what the cause was. The original expansion valves work very well with R134a. I'm thinking of jumping the temp switch and leaving the fan on to see how it does. With R134a you do not rely on the site glass. R12 Expansion Valve with R134A charge? - Maverick B. Hmmmm. But R22 is almost equally damaging. 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. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. About four or five years ago, I guy with an MB came here with the same problem, that tread was over six pages long. I'm having the same concern. R 134A is designed for the high demands of an automobile AC and cannot be used on refrigerators due to pressure differences. There are two hoses listed, R-12 64-53-1-377-821 for $72.50, and R-134a 64-53-8-391-051 fro $262.50. I used a full can of evap cleaner. I think so. In addition, R134a refrigerants are not only used in auto air conditioners, they can be used in freezers, aerosol cans, and refrigerators. The oil used in R12 and R134a are different and not compatible. 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. Some 1993 and older R12 systems aren't as 'compatible' as you'd think to switch over. This is not to say that one of these small retro-fit kits cant be used, however to be used wisely. What is needed? A. Pressure/temperature plot of R134a vs. R12 is shown in figure 1. Note that passwords are case-sensitive. and recharged with mineral oil and 2.2 lbs R12. R12 was once used in many air conditioning units as a refrigerant or cooling agent. and an evaporator core and expansion valve that are optimized for R134a . Unfortunately, the R12 refrigerant doesnt always blow cold air. Here are the basics for converting a system that does not have a charge of R12, its empty. You'll want the expansion valve matched to whatever refrigerant you're using. R-134A has a slightly lower pressure at evaporator temperatures (30-40 degrees), but R-134a also has a much higher pressure at condenser temperatures (120-150 degrees). R134a refrigerant is about 10% less efficient in moving heat than R12! That switch should close @ 52c. The best oil that runs well with R134a is PAG oil or Polyalkylene Glycol. 05-25-2017 02:14 AM. An extra half ounce? July 3, 2022July 3, 2022. Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). The old compressor used R12 and the new unit will be R134a. The common problem when converting from R12 to R134a is lack of knowledge or equipment. I remember I had the wrong seals and it leaked some oil, so I put some more in.Bohica - I tested the pressures. You are indeed 20% out of the OEM spec for cooling. Bottom line, R134a simply doesn't cool as well as R12. Depending on which circuit diagram fits your car (cough, no vin list exists) you have either one or two switches controlling the aux fan. The safe high side pressures are determined with a PT (pressures and temperatures) chart. Get to the point where I can walk without crutches2. There are R134a specific valves that operate at a slightly different pressure, but not for any "old" automotive application that I'm aware of. difference between r12 and r134a expansion valve why is miles raney not on homestead rescue June 21, 2022. manila mayor candidates 2022 R134a vs R12 - What is the Differences? - Rx Mechanic Safe but sorry! With the oil leaking out and being told all sorts of things about how these compressors don't have a sump etc, I wanted to be on the safe side. The OEM spec is 2300 rpm @ 12.6v (engine stopped fully charged battery). What is a T/C?4. Even though their common major function is to cool the system, they have many differences. One thing at a time here, and slowly, the knee is not up to jumping around like I used to at the moment. Thread starter goldNSX; Start date 1 August 2009; Tagged . Accessories Pumps, Cooling Towers, Evap Condensers, etc, Components Valves, Motors, Condensers, Evaporators, etc, Duct Systems Design, Installation & Practice, Piping Systems Design, Installation & Practice, Control System Design, Installation & Practice, Pro's Forum: National Electrical Code (NEC), Pro's Forum: Calculations & Electrical Theory, Pro's Forum: Electrical Business & Marketing. difference between r12 and r134a expansion valve Is it exponential, squared? James10952001. You'll get marginally better performance out of the change as the expansion valve is matches the refrigerant characteristics. . There are three different refrigerants officially sanctioned by the EPA for automotive usage: r-12, r-. 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. 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. 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. 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. Spray it deep, and let it sit for a few minutes. Warning: "continue" targeting switch is equivalent to "break".Did you mean to use "continue 2"? Since there is only about a 10% difference between R-12 and R-134a, the expansion valve being self-compensating really doesn't make that much difference. Performance doesn't seem to have improved. The cable is adjustable at the valve arm. Remove the old mineral oil from the compressor by turning it upside down, side to side, and turn the front hub on the clutch assembly. Inasmuch as R134a has a global warming potential thats over 1000 times more threatening than carbon dioxide, its better than R12. Is there a graph? ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. The evap is hard to get at. 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. #13. Therefore, the higher the factor of the chemical (compound), the greater its effect on global warming. Differences between R-12 and R-134a systems: 1. Though I have seen em run as cold as 12 deg F. If the thermo switch is malfunctioning. That would be the "black death" syndrome. Poc temps desprs van decidir unir els dos webs sota el nom de Xarxa Catal, el conjunt de pgines que oferirien de franc sries doblades i/o subtitulades en catal. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. Trinary Pressure Switch $ 39.99. 30 deg is pretty coldSystems generally run between 40 and 43 deg. Generally this works well for the whole system. Since 2010, all home AC systems manufactured use a refrigerant like R134a that has zero ozone depletion potential (ODP). With R12 you use to check to see if the site glass was full, if it had bubbles it meant you had a low charge. 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. R134a systems operate at higher discharge-side pressures than R12, which can cause compressor seals to leak. Its chemical symbol is CH2FCF3. Production of R12 ceased in 1996, although it can still be reclaimed, purified, and resold, and small cans of New Old Stock R12 are still widely available on eBay and Craigslist. This refers to BTU's (heat) moved per pound of refrigerant moved. Compressor. The major reason for the replacement of R12 with R134a was to curb future greenhouse effects. And yes - expansion valves sometimes need replacing if they are sticky - but a proper AC flush should eliminate the need for a new one if it's already in good condition. R12 to R134a change expansion valve? - HVAC-Talk: Heating, Air This kit comes complete with Expansion valve, o-ring kit, and 1ft. R12, on the other hand, is called chlorofluorocarbon (CFC). |. I have one can left, so maybe a plan can be made. R134a. It's helluva humid and hot here in north florida, and I drive around all day for my job. 5. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge. As illustrated in the chart below, the curves below run together nearly throughout the curve, only slightly breaking paths at around 250 psig/150 degrees and above Flammability/Safety R-1234yf has been designated as MILDLY flammable. 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. AFAIK, there is no clutch on the engine fan on the 240D. 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. R404a is a zeotropic blend with a temp glide , because of the mixture of 2 or more refrigerants. The car never overheats, if that has any import. 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. Have a look in the FAQ Section, and look for "Fan clutches & testing them". 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 general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. Mine was 61, so the system is not working as it is supposed to. Its chemical symbol is CH2FCF3. Different correction factors are applied to other refrigerants. But I've read that these car's didn't do too well in the a/c stakes, so that might just be as good as it gets. And, unfortunately a small high side pressure gauge on a short hose. Also, it can be used with all types of compressors. Is that reasonable?Vent airflow is good, I think. 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. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. Not going to mess up your 'do, but you can feel it. 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. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. Can I just use an adapter and save $200? Als nostres webs oferimOne Piece,Doctor Who,Torchwood, El Detectiu ConaniSlam Dunkdoblats en catal. It is usually sold under the brand name, Freon 12. R12 is CFC: Even though R12 is one of the most commonly used refrigerants, it is CFC. The larger fitting goes on the discharge port and the smaller fitting goes on the suction line or compressor inlet / suction port. Replacement expansion valve for R134a or R12 A/C refrigerants, with O-ring connections. This may be the source of your oil confusion. Its highest value is 1. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. Very interesting! 1.5 ounces - hmmm. 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. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. -------------------------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. Ask Our Pros-Owner Assistance - NO DIY advice will be given. Any advice appreciated. Amazon.com: 134a Valve We've updated our forums!Click here to visit the new forum, Year: 1991Make: Jaguar Model: XJ6Engine Size: 4.0. VerticalScope Inc. All Rights Reserved. By after changing just about everything, he got what was termed, satisfactory cooling. 37 in 2005 tacoma, R134A. Just had knee surgery yesterday, so I"M not exactly hopping around too well. difference between r12 and r134a expansion valve. PDF COMPARISON OF Rl34a AND R12 REFRIGERANTS IN A VAPOUR - AIVC 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. Edited: Sat July 14, 2007 at 10:22 PM by fonebone. I'm putting r12 back in my system, but all of the valves I can for the application (1990 jeep grand wagoneer) say r134a on them. Effects of alternative refrigerants on the ejector dimensions for The next piece of equipment to track down leaks is a leak sniffer. R-12 vs R-134a Hose - Pelican Parts Forums It won't be optimal, though. CONCLUSIONS The differences in the theoretical C.O.P.H calculated for R12 and R134a are consistent with values quoted in the literature. The cure is to use the newer R134a compressors is sealing washers that are different thickness.

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