The chemical composition of R12 and R134a differ. Break out the new gauges and measure hi and lo at 1500rpm, and do the Merc FSM test to see how we're doing performance wise. I have the original (R12) style expansion valve in the Maverick AC system. When ever possible you should ask the technician to note the same information on your repair bill and keep a copy in your glove box for future reference. "Jerky Locker" LMAO I am using that one in the future!Florida = BUGS! 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!) Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. The AC usually does not work at all. Some 1993 and older R12 systems aren't as 'compatible' as you'd think to switch over. -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. and feeds it through an expansion valve. R12 is otherwise called dichlorodifluoromethane is a colorless gas (chlorofluorocarbon halomethane (CPC) that is used as an aerosol spray propellant and a refrigerant, and is soluble in organic solvents. About four or five years ago, I guy with an MB came here with the same problem, that tread was over six pages long. R134a. Besides, its technology has been tested and trusted. 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. James10952001. -------------------------"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." With tube & fin condensors in MVAC applications there is never "too much" airflow. Moreso, it had been banned. In more serious, it could result in cardiac irregularities or death. CONCLUSIONS The differences in the theoretical C.O.P.H calculated for R12 and R134a are consistent with values quoted in the literature. The pressure at low temperatures is nearly the same between 12 and 134a. The problem with these so called drop in replacements is that to properly handle them you may need dedicated equipment to identify the gas and evacuate it for proper disposal. Even with proper fan operation, missing seals & air dams can effect condensor effeciency. We recently created this blog site to enable us to share our knowledge with other automotive mechanics and car owners. Welcome to rxmechanic.com. Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. A. Pressure/temperature plot of R134a vs. R12 is shown in figure 1. In large application systems, the vapor density of this refrigerant is usually high. Thanks again. This is 11F off the FSM performance graph - vent should be around 50F. 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). 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. System has been working fine for a year. 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. in /nfs/c05/h04/mnt/113983/domains/toragrafix.com/html/wp-content . Its chemical symbol is CCl2F2. Its chemical symbol is CH2FCF3. You do not want to exceed the systems high side recommendations. If you are replacing other system components, such as condensers, driers or hoses, you may need to add more a/c refrigerant oil to the system. They plug all the time. In no particular order, here's what I've found out regarding answering the questions posed so far:Fonebone - It is definitely an R4 compressor (they left the c off the front and the p off the end, i.e. Could that be screwing up the systems performance?Anyway, when I installed the system, the new TXV (is that short for expansion valve?) (You must log in or sign up to reply here. I have just bought gauges. 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. The expansion valve(Tx) is in the car at the inlet line to the evaporator with compressors you best get advice from an ac specialist shop as the differences could be the gas that it pumps some systems use R12 and others use R134a or later gas yes R1234yf Freon gas can be replaced by R134a; the newer systems were designed with this in mind so no, there will be no damage to the compressor but some time in . Jun 17, 2011. a 50f delta across the condensor is good, but I suspect that is an idle reading. I don't think it has any air dams or seals, I'll check to make sure. . However, the supply houses don't indicate a difference. Rules governing changing from the former to the latter differ between countries. If you have a perfectly operating system using R12 you do not have to drop what you are doing and convert to R134a. This is due to many facts: R134a refrigerant is about 10% less efficient in moving heat than R12! You should keep in mind that recharging your air conditioner improperly could result in more serious damage. A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . 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. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. Add to cart. Very interesting! The Main change in the system is the expansion valve. Why wait for 200f on the engine coolant to start the fan? 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. Some say that a chemical reaction can harm the A/C very badly as R134a reacts with mineral oil in some way. The original rubber a/c hose lines in your car will leak out R12 through the hoses lining. Please enter a password for your user account. It's best to determine on a case-by-case basis while monitoring system pressures and output air temperature. . R12 is used in several applications like low temperature, medium temperature, and high-temperature applications. 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 A final difference is that most (though not all) R-1234yf cars will have a Suction Line Heat Exchanger. 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. R134a has an ozone depletion potential of 0, implying that it has a slight effect on the ozone layer. These two refrigerants are the older types and are not used in newer refrigeration and air conditioning systems. Any advice appreciated. Took me a while to figure that one out, and how to say that. The system has been previously converted to R-134a. -------------------------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! Comparatively, larger R134a molecules should take more space, and a smaller amount might be required. "Howdy, Folks!" Mine was 61, so the system is not working as it is supposed to. But, what is considered a good temperature differential across the condensor? 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. Gain access to our free AOP (Ask a Professional) Section to get real answers for your questions. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. Fitting a PF condensor is not rocket science, but it requires some planning. This means that it has a high potential of causing depletion to the ozone layer. 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. Is there a graph? Carefully study the chart and compare the following: To a large extent, the choice is up to you. I'm not sure. The ARPA Zone/Open Membership Discussion Forums. Some compressor manufacturers or OEMs suggest PAG type oil for R134a. Depending on which circuit diagram fits your car (cough, no vin list exists) you have either one or two switches controlling the aux fan. ). July 3, 2022July 3, 2022. You do not however need to replace all the o-rings or seals for a simple conversion, it is simply a logical thing to do when and if the time comes to work or replace certain components because of age issues. R134a requires a different oil. sparkee said: Thanks for the Service Bulletin. 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. . The difference really shows up on the high side. 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. Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. That switch should close @ 52c. VerticalScope Inc. All Rights Reserved. I'm doing one thing at a time so I know what the cause was. Looks like a couple of things happening here1) 80's vintage Eurocars were not "meat lockers". It cycles on off in med (or low for that matter)Gotta tell ya. Then when it is switched off for a few minutes and then back on, the air cools again. The MB chart shows 360 psi with R12 in some conditions. Its among the greenhouse gases and will keep adding the current problem of heat not leaving the earths atmosphere. Instead of using R12, its preferable to use R134a because it is very easy to find in the market, its sold at an affordable price, and is environmentally friendly. Can I use the one for the R-12? However, theyre still used in older plants, systems, and the automotive industry. This is a great space to write long text about your company and your services. Unfortunately, the R12 refrigerant doesnt always blow cold air. The only difference I can imagine would be the recharge connection. Right now you know you have a bit too much, but with a CR4P compressor this is an insurance policy. However, you can convert R12 to R134a by yourself, save money and keep all the tools purchased. With the A/c off hi and lo were both at 105psi. At 2000rpm, windows open, highest fan, hi pressure stabilized at 225 psi, low 25psi.Ambient 81F, vent 61F. Swapping the components isnt a herculean task, but recharging the AC is a challenge. R134a requires the use of synthetic oil! A lower GWP alternative to R-134a had to be found and thus we have the new 1234yf. ing the expansion valve, a maximum opening superheat of 7F, and a standard factory air test superheat setting. 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. 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. You do not need to replace every o-ring in the system, but if you happen to open a connection that has an o-ring you should replace the old o-ring with one that is compatible with R134a and lubricate the o-ring with ac oil. shown for the parallel flow, aluminum condenser that is listed. In most cases, the systems used have varied components, designs, and service ports. -------------------------"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." If there is no pusher fan, and you have the room, put one in. Is there a source of valves by, say, eaton number? A Lot of the fins are bent, especially at the top. = R134a Charge Level. For instance you can evacuate FRIGC FR-12 into a refrigerant recovery bottle that has R134a in it or visa versa. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. I cleaned the evap as best I could, if that is what you are getting at. Hopefully after you have read this entire page you will have enough information to determine which type of refrigerant is best for you. The larger line at the expansion valve is the suction line. You can buy bulk hose, and the proper fittings, then have them crimped off the vehicle.Be sure that no air bypasses the new condensor on the way to the radiator. All pre-97 XJs use systems with the same basic operating principle, although the parts do change a bit. The original CFC expansion valve used for R12 needs to be replaced with an HFC one for 134a to feed the evaporator correctly. 2) Frost on the Vents. Where would I get some basic info on it, I know nothing about it. 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. Therefore, the higher the factor of the chemical (compound), the greater its effect on global warming. Jun 19, 2007. 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. Can I just use an adapter and save $200? I put one in my old daily driver '79 Chevy tank (r-12), and it really made a difference. Automotive Replacement Expansion Valves & Parts; Industrial & Scientific; Customer Reviews. asia pacific stevie awards 2021. gin, amaretto cocktail. . Tamb oferim en VOSC el contingut daquestes sries que no es troba doblat, com les temporades deDoctor Who de la 7 en endavant,les OVA i els especials de One Piece i molt ms. Refrigerators generally utilize R22, R32, or 410A-based coolants as their cooling agent. I remember I had the wrong seals and it leaked some oil, so I put some more in.Bohica - I tested the pressures. Debug the condensor (I am a computer nerd after all!)3. But as there's not a big difference, people say you can suffice with either. The cure is to use the newer R134a compressors is sealing washers that are different thickness. I am ordering new parts, and planning to convert my system to R-134a. CR4P). Use a strong surfactant like Simple Green or Zep Citrus, and soak the fins on the condensor. . Therefore, its most suitable for both commercial and domestic environments. Is there more info needed?THanks -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a, Paul:I had to dig a bit deeper - MB made several running changes in the 1983 123'sThere are actually 4 different circuit diagrams for the A/C system that year - just for your 123.123 I found the R4 reference, and it should have 170 Ml of oil in the system.Your aux fan should run at the ambients you listed. I know this is bad, etc, and deposits on the metal can act as insulators. 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. Make sure to get the R12 EXP valve if that is the way you go. A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . It's actually a reaction with chlorine in the mineral oil that may have been absorbed and leftover from the old R-12. Edited: Tue July 17, 2007 at 3:25 AM by bohica2xo, I believe there is only one switch - the refrigerant switch. Still, I have some simple green, so may as well give it a go. 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. R1234yf is more environmentally friendly and has a global warming potential of 4. You will be fine with a 134a-compatible TXV running R12. For example, if your system originally had 36 ounces of R12 then you multiply that by .80 and you have 29 ounce of R134a. absorb by the evaporator to insure all liquid refrigerant entering the evaporator. video clubhouse baseball; nick fairley draft profile; ben davis work pants Thanks so much Bohica - you've save me many more hours of fruitless speculation. The experimental values of C.O.P.H obtained with the R134a/ester charge were 20.2% 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. 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. 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. Safety: R134a is safe to use as its non-flammable and cant explode. . Bottom line, R134a simply doesn't cool as well as R12. Lets take you through the advantages, disadvantages, and differences of these two refrigerants a detailed comparison including R12 vs R134a performance. 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. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. The only difference I can imagine would be the recharge connection. Even if the system leaks, repairing the leaks and recharging it with R-12 is usually the best repair alternative. A slow loss of cooling at city speeds is usually related to condensor capacity & airflow issues.You could improve the cooling capacity by replacing the condensor with a high effeciency parallel flow unit. Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). Most of all the differences gravitate to longevity, functionality, and safety. I'll report back on the aux fan on performance next. Recovery & flushing is the only way out of an oil overcharge in your vehicle.B. The name of the oil is Polyol Ester (POE). I mean, really a lot. The major reason for the replacement of R12 with R134a was to curb future greenhouse effects. system of 0.33 TR and refrigerant used was R12. The whole trick is to sit there in those steam boxes and not perspire, it's vulgar to perspire when driving on public roads.If you want esteem, drive an MB, if you want comfort with 60*F interiors in a 125*F environment, get a Caddy. R-134a can actually cool better than R-12 in a well designed R-134a system as it has better thermoconductive properties, but all the high pressure issues have to be addressed.But even when these cars were brand new, didn't cool worth a damned, recall almost dying in one in Las Vegas at the time, but a good way to lose weight with gallons of perspiration pouring out, just don't let that drip on the seats, that is inappropriate. R134a was selected as a replacement refrigerant for R12 because R12 contains chlorine and has a major effect to ozone layer depletion. 1) Warm Air From Vents. Not going to mess up your 'do, but you can feel it. R134a Refrigerant Recharge Kit with BPV31 Bullet Piercing Valve and R134a Quick Coupler, R134a/R-12/R-22 Freon Refrigerant Hose Can Tap Kit for A/C System - Easy to use. Be sure to test @ 1500 to 2000 engine rpm, and record the ambient temp as well. . and he synthesized R-134a in 1936, 5 years after R-12 was . Are r12 and r134 fittings different? R-12 to R-134a Conversion. The primary function of the design engineer is to make things difficult for the fabricator and impossible for the serviceman. The best oil that runs well with R134a is PAG oil or Polyalkylene Glycol. R-134a XV for R-134a use. Make sure to wear safety gloves, goggles, and shoes when theres a possibility of exposure to the chemical (R134a). The cost of recharging the air conditioner is between $150 to $500. At least you do not have 16 ounces in there ( yup seen it before).For now, straighten all of the fins that you can, clean the condensor well, and re-test with the aux fan running. The system has been previously converted to R-134a. Hope this helps. We mention using ester type refrigerant oil. Before we mentioned that you can add approximately 5-6 ounces of ester oil to the compressor. 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. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. Thus, when the system is running, condensing the CO2 is not a problem. Pound for pound R134a is a more efficient refrigerant than R12, however it runs at higher pressures in some aspects and therefore requires more effective condensing. In a car ac, using this type of freon 20 years ago was difficult. Most importantly, the oil used in the plant must always be compatible with the refrigerant used. Gnats & mosquitos will clog deep. All fans must work at 100% of the OEM rating. Performance doesn't seem to have improved. There is only a temperature switch on these cars as far as I recall, and it just switches on the aux fan. R134a vs R12 refrigerant? Measure what you have now.3) Go back to the page in step one, and find the largest condensor you can put in your vehicle. of refrigerant insulation tape. Yes, I don't trust the heater valve either. Please enter a valid email address for yourself. Replacement expansion valve for R134a or R12 A/C refrigerants, with O-ring connections. R134a is called tetrafluoroethane (HFC). If there is a resource I should read first to save you time, let me know. 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. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. Catalog E-1, Thermostatic & Automatic Expansion Valves / Page 1 Table of Contents . R-12 is no longer used or produced in many countries and remaining quantities have skyrocketed in price. 2001-2023 Griffiths Technical Inc. All Rights Reserved. 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. This drop can affect energy consumption since the plant will operate for a longer period or a larger plant will have to be installed. I've straightened the fans I can and sprayed simple green on it, let it soak then hosed it down well. Related products. we convert older systems where i work all the time and they work fine. Expansion Valve. Shorting the plug for the refrigerant switch should run the fan when the compressor is on. The aux fan didn't switch on though and I didn't check the high side temperature. 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. A comparison between R12 vs. R134a temperature will show that R12 has a higher temperature than R134a. Ask Our Pros-Owner Assistance - NO DIY advice will be given. BTW, I use a stick thermo in the vents and the laser on the condenser.

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