They have no moving parts. R134a requires a different oil. Related products. The safe high side pressures are determined with a PT (pressures and temperatures) chart. Very interesting! June 21, 2022 difference between r12 and r134a expansion valve . I don't recall all the details, but starts off with the largest parallel flow condenser and improved fans. For instance you can evacuate FRIGC FR-12 into a refrigerant recovery bottle that has R134a in it or visa versa. R12 is simply too expensive for a 25+ year old A/C system. Bohica, I appreciate your help with this. Lets take you through the advantages, disadvantages, and differences of these two refrigerants a detailed comparison including R12 vs R134a performance. Debug the condensor (I am a computer nerd after all!)3. Use a drop light in the engine bay, and check the air path from the front of the car at night. 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. And I lied about the compressor switches on this car - there are 2 switches on the drier - a temp and a pressure switch. R134a is the most widely accepted alternative automotive refrigerant used to replace R12. Replied by Rich928 on topic R12 or R134a. Comparatively, larger R134a molecules should take more space, and a smaller amount might be required. The next piece of equipment to track down leaks is a leak sniffer. Generally, the new amount is 75-85% of the quantity advised by the manufacturer. James10952001. Besides, its technology has been tested and trusted. If 50 degrees across the cond. Any ideas from the info above? Safe but sorry! -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a, Bohica, You say the drop in performance is not linear with too much oil. 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. . Or is there always room for improvement, the more the merrier. Are r12 and r134 fittings different? A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. That way I will have reduced the oil by about 1/3 (assuming the oil is mixed evenly through the system). 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. Please enter the name by which you would like to log-in and be known on this site. 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. Thanks so much Bohica - you've save me many more hours of fruitless speculation. Besides, you have a greaseisel. It does not "pool" to any degree in a large amount anywhere. What effect would it have on performance, if any? You can also check the Aux fan in your case. R12 was once used in many air conditioning units as a refrigerant or cooling agent. 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. I've done the FSM test and with 81F ambient, the vent should be 50F. They examined the two configurations of capillary tubes i.e. Still, I have some simple green, so may as well give it a go. The original rubber a/c hose lines in your car will leak out R12 through the hoses lining. R404a is a zeotropic blend with a temp glide , because of the mixture of 2 or more refrigerants. For R12, its mineral oil. I know this is bad, etc, and deposits on the metal can act as insulators. The system has been previously converted to R-134a. I'm going to check the condensor is way clean too. Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. Pray I can let some oil out of the compressor without losing my precious R12. I don't want to be chasing ghosts. This is the part that controls the system pressures. Its chemical symbol is CH2FCF3. The pressure at low temperatures is nearly the same between 12 and 134a. Most vehicles manufactured before 1993 have the R12 A/C system. I remember I had the wrong seals and it leaked some oil, so I put some more in.Bohica - I tested the pressures. For example, at an evap temp of 30 (your daughter's system is probably running around 25-28 saturated in order to give a 32 duct temp), the pressure of R-134a is 26.1psi. R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. 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. The MB chart shows 360 psi with R12 in some conditions. The original CFC expansion valve used for R12 needs to be replaced with an HFC one for 134a to feed the evaporator correctly. It is perhaps possible to locate a unit with a company that purchases close out or distressed merchandise. I'm curiousSo there is work to do, ie performance should be able to be improved. -The amount of R-134a needed will typically be 80-90% of the R-12 charge. Superheat you can consider to be the additional amount of heat. Your decision could be made based on economics, environmental concerns, or both. All pre-97 XJs use systems with the same basic operating principle, although the parts do change a bit. Als nostres webs oferimOne Piece,Doctor Who,Torchwood, El Detectiu ConaniSlam Dunkdoblats en catal. R1234yf is more environmentally friendly and has a global warming potential of 4. Compared with the cost-performance ratio, R507 is 30-40% . We sometimes use a relay switched from the compressor clutch to run fans. 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. Its highest value is 1. Compressor. R-134a XV for R-134a use. The R134a compressor has a 1/8" step in on the high side port. Yes, this was a smokers car. As for R134a and R1234yf, theres no room for conversion. Any suggestions, or do you need to know the hi/lo readings? Is there a difference in the expansion valve for R12 as opposed to R-134a? In more serious, it could result in cardiac irregularities or death. and an evaporator core and expansion valve that are optimized for R134a . In a comparison between R12 vs R134a vs R1234yf, R1234yf will pass as the best refrigerant. 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. Stability: RR12 doesnt disintegrate even under extreme operating conditions. Your average garage that works on a/c on the side probably would not have this. I would not do a 134a conversion without a PF condensor. Usually, mechanics charge around $200 for conversion. Also the new quick connect fittings for the high & low side. Heres some important advice Whenever you notice your R12 refrigerant is leaking, turn off all flames and open the doors so it can escape to the open atmosphere. 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. Is there a difference between a R134a expansion valve and an R12 TXV? It is mixed with the freon for the most part, and does accumulate in all components in small amounts. At 2000rpm, windows open, highest fan, hi pressure stabilized at 225 psi, low 25psi.Ambient 81F, vent 61F. I don't believe it is but I had a service guy tell me it needs to be done. Does it matter - assuming both are new & uncontaminated? 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. R-12 is no longer used or produced in many countries and remaining quantities have skyrocketed in price. R134a vs R12 refrigerant? As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. The analysis focuses on Coefficient of Performance for . 4.3 out of 5 stars 491. 5. What is a T/C?4. 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. Sense ells no existirem. R134a systems operate at higher discharge-side pressures than R12, which can cause compressor seals to leak. 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. 37 in 2005 tacoma, R134A. They plug all the time. On this website we are addressing only R134a and not other suggested drop in replacements. All fans must work at 100% of the OEM rating. We mention using ester type refrigerant oil. Can I just use an adapter and save $200? The ratings for evaporator temperatures 40F, 20F, -10F, -40F in the capacity tables are in accordance with ANSI/ARI = R134a Charge Level R12 Expansion Valve = 201 830 06 84 R134A Expansion Valve = 201 830 04 84 Is there a difference after all? If you have the work done, be sure you find a true "A/C" shop that can make up lines. 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. There are R134a specific valves that operate at a slightly different pressure, but not for any "old" automotive application that I'm aware of. A vacuum pump, a refrigerant recover system, quality service gauge set with both low and high side gagues, and much more besides the lessons to learn what to do and what not to do. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. Carefully study the chart and compare the following: To a large extent, the choice is up to you. The AC usually does not work at all. It is also used in automotive car conditioning and the plastic industry. 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. So you could likely put off buying those new hoses just a bit longer if you wanted. R134a is otherwise called 1,1,1,2 Tetrafluoroethane, Florasol 134a, Freon 134a, Norflurane (INN) or HFC 134a. Further production of R12 was banned in some developed countries by the Montreal Protocol because of its harsh effect on the ozone layer. evarporator, expansion valve plus flushing out the full system and replacing all the o rings. Condensers designed to release greater amounts of heat help to expel the greater amount of heat which R134a removes from the cars interior. 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. And by matching the correct amount of R134a to use in a given vehicle, correcting the superheat of the expansion valve (if necessary), you can in some manner nearly balance or match the amount of heat drawn out by the evaporator and released by the condenser. R134a has the chemical formula CF3CH2F and is known as tetrafluoroethane. How an A/C Expansion Valve Works. Inasmuch as R134a has a global warming potential thats over 1000 times more threatening than carbon dioxide, its better than R12. difference between r12 and r134a expansion valve. 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. Crap! I don't know where it is getting the switch off command, or why the vent temp drops steadily. They can be mounted quite easy,and there is a mounting kit that helps to hang it. The ARPA Zone/Open Membership Discussion Forums. . This allows the refrigerant in the condenser to be void of oil particles. video clubhouse baseball; nick fairley draft profile; ben davis work pants So, instead of using R12, other better options include R401b, R134a, R401a, etc. Moreso, it had been banned. 05-25-2017 02:14 AM. Skin contact: If the R134a (liquid) comes in contact with your skin, it could cause a burn. Right now you know you have a bit too much, but with a CR4P compressor this is an insurance policy. (On firewall where A/C lines go into cab.) We consider the the various types alternative refrigerants that are illegal or not approved to be in two sectors: non-flammables and flammables. Expansion Valve. There are three different refrigerants officially sanctioned by the EPA for automotive usage: r-12, r-. Automotive Replacement Expansion Valves & Parts; Industrial & Scientific; Customer Reviews. The difference between the two is about 10,000 btu/h. We recently created this blog site to enable us to share our knowledge with other automotive mechanics and car owners. July 3, 2022July 3, 2022. R404a for freezing of product. difference between r12 and r134a expansion valve. Blows pretty hard on full. The value of carbon dioxide is 1. 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 had to vaccum the system for 2 hours and recharge 4 oz of PAG oil plus 36 oz of 134A freon (3 cans). It's actually a reaction with chlorine in the mineral oil that may have been absorbed and leftover from the old R-12. 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. By using a black light the dye will glow in areas where oil leaks are visible. Then again, there are two different expansion valves. R134a. Expansion Valves Catalog E-1, July 2012. To bless the system the technician should attach a R134a sticker somewhere in the engine compartment to note the car is using R134a. Trinary Pressure Switch quantity. The cure is to use the newer R134a compressors is sealing washers that are different thickness. The symbol implies that R12 is a composite of carbon, chlorine, and fluorine. _____ 2012 E350 2006 Callaway SC560 . The difference between R12 and r134a is the BTU carrying capability. This works when the R12 charge specification is listed in pounds. 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!) I could easily be over at least 2 - 3 ounces over on the oil. difference between r12 and r134a expansion valve. 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 again, there are two different expansion valves. I found that in the..Maxposition on the control it will have the compressor running all the time. Figure 2 shows the different phases and pressures the refrigerant . 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. look at the difference! Here are the basics for converting a system that does not have a charge of R12, its empty. Generally this works well for the whole system. Table 1 summarizes the technical characteristics of three potential R134a alternatives. 4 Stars & Up & Up; 3 Stars & Up & Up; 2 Stars & Up . R134a requires the use of synthetic oil! Biggest you can fit in there is best. 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. Is that why expansion valves are specific to R12 or R134A? In the automotive world, the replacement for R12 was R134a. It is possible I have 10 ounces (250 ml) in the system. link to How to cut off a Catalytic Converter. Have a look in the FAQ Section, and look for "Fan clutches & testing them". That is a good thing. You do not need to replace the expansion valve in most cases. Thomas Jefferson, Thanks,OK, I'm starting to feel a little better about it. 3) A/C Compressor Always On. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. Paul:It is never a waste of my time to chat with someone that understands the problem, and wants to fix it. Yes it will work with either Refrigerant! 42 (at best) w/ 134A in 2000 isuzu trooper. B. When the ambient air temps get above 80F the gauge readings can run a bit higher on the high side and lower on the low side when using R134a. Its duty is to convert toxic gasses produced by the engine into A brake cleaner is a powerful solvent for cleaning dirt from the brakes and other car components. 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. I'm thinking of jumping the temp switch and leaving the fan on to see how it does. How is the vent airflow?I would jumper the aux fan & check the performance. Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. To prevent refrigerant loss you should consider replacing your old hose lines with barrier type hose. Not going to mess up your 'do, but you can feel it. From memory, I put in at least 8 ounces of oil, probably around 10 ounces in there. Therefore, its most suitable for both commercial and domestic environments. -------------------------"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." In most cases, the systems used have varied components, designs, and service ports. Temp switch works the aux fan. I cleaned the evap as best I could, if that is what you are getting at. 5. I'm not sure. 2022 nba 2k22 starting a fashion label signing the designer, a difference between r12 and r134a expansion valve, 2020 white paper of the church of pentecost, Chime Mobile Check Deposit Funds Availability, Why Does James Kill Donald In The Vanishing, nba 2k22 starting a fashion label signing the designer. However, you can convert R12 to R134a by yourself, save money and keep all the tools purchased. It's not just the poor performance - the cooling just stops working after a while. You either get a system that will function well with R1234yf or get any other type. The aux fan didn't switch on though and I didn't check the high side temperature. 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. Flushed, vacuumed etc. If the system was upgraded by a professional it should have an upgrade sticker. R134a refrigerant is about 10% less efficient in moving heat than R12! You do not want to exceed the systems high side recommendations. 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. The crossover point is approximately at 64F. 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. We've updated our forums!Click here to visit the new forum, Year: 1991Make: Jaguar Model: XJ6Engine Size: 4.0. The best replacement for R134a is R1234yf, while R12 refrigerant replacement was R134a. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. In 1994 they switched from R-12 to R-134a. Are you sure you have an R4? If you have 10 ounces of oil in the system, that is contributing to the poor performance as well. By after changing just about everything, he got what was termed, satisfactory cooling. Warning: "continue" targeting switch is equivalent to "break".Did you mean to use "continue 2"? 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. In cases such as this, the required capacity value of the expansion valve with R134a is reduced by 30% (correction factor 1.42). But, what is considered a good temperature differential across the condensor? The global warming potential of R134a is 1430. PaulJerky King -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. These two refrigerants are the older types and are not used in newer refrigeration and air conditioning systems. difference between r12 and r134a expansion valve why is miles raney not on homestead rescue June 21, 2022. manila mayor candidates 2022 Performance doesn't seem to have improved. You are indeed 20% out of the OEM spec for cooling. I recommend replacing the expansion valve when you do the swap. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. You may have heard of a friend that did the job himself with borrowed equipment and 12 or 16 ounce cans of refrigerant. The car never overheats, if that has any import. GWP is a measurement of Greenhouse Gases and their effect on Global Warming. The cost of recharging the air conditioner is between $150 to $500. What is the refrigerant property involved that has caused this? It would make a big difference at idle ,in traffic!! You can use the R134a retrofit capacity chart for this purpose. 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. 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. So that indicates it is cooling well there doesn't it? Until 1995, most cars with air conditioning used R-12 Freon refrigerant which has shown to have an environmental impact. 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. The experimental values of C.O.P.H obtained with the R134a/ester charge were 20.2% Only show this user. The only difference I can imagine would be the recharge connection. 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. Once you have replaced the OEM condensor with a PF unit, you will need to make custom hoses to mate with your OEM system. I'll put the relay on for that. 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. On the other hand, R12 has a global warming potential of 10,910. Questions About Becoming A Professional Member? . we convert older systems where i work all the time and they work fine. . The mechanical fan & clutch should be checked as well. A York oil capacity is listed as "6.5 to 9.6 ounces". Is there a difference between a R134a expansion valve and an R12 TXV? 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. Also, R134a cylinders are light-blue in color. 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. We, the Rxmechanic team, have presented a well-detailed comparison of R134a vs. R12. Failure to abide by the EPA regulations can result in expensive fines for either you or your service technician. In a car ac, using this type of freon 20 years ago was difficult. Refrigerators generally utilize R22, R32, or 410A-based coolants as their cooling agent. Hope this helps. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? Gain access to our free AOP (Ask a Professional) Section to get real answers for your questions. Thus, when the system is running, condensing the CO2 is not a problem. compressor, condenser, evaporator and expansion valve are specifically designed for use with R134a. Generally the system will be initially charged with approximately 80% to 85% of the original amount of R12, using R134a. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores. The global warming potential measures the amount of heat trapped by any gas compared to the amount of heat trapped by the same amount of carbon dioxide. Recharge the compressor with a/c ester oil and a tracer dye. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . The oil used in R12 and R134a are different and not compatible. 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. _____ 2012 E350 2006 Callaway SC560 . Lasers don't do well on vent temps, a stick thermometer is better in that application. Big . 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. Also called the orifice tube. However, theyre still used in older plants, systems, and the automotive industry. Its chemical symbol is CCl2F2. The adjusted tension of this spring is the determining factor in the opening and closing of the expansion valve. 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. Rich Membership Chairman Using R134a in an R12 system will cause the oil not to move with the refrigerant, causing a system failure and probably won't even cool the system well, if at all. As noted, measure up front as best as you can to get as close to the aftermarket dim. A/C systems designed to use R-12 will cool best when charged with R-12 refrigerant. This is due to many facts: R134a refrigerant is about 10% less efficient in moving heat than R12! There are other refrigerants: some of which may work, some of which dont work, some of which will destroy your a/c system and some of which are dangerous. If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? Whether R134a performs as well as R12 in any given a/c system depends upon system components and the amount of R134a used. Some say that a chemical reaction can harm the A/C very badly as R134a reacts with mineral oil in some way. A comparison between R12 vs. R134a temperature will show that R12 has a higher temperature than R134a. It may take a couple of tries to get things really clean.The laser is usually close on clean surfaces, but I prefer a T/C. 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.
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