It was later found that R-134a had a very high Global Warming Potential, or GWP, number. The condensor airflow drops off as the fan clutch dies slowly. 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. . I don't believe it is but I had a service guy tell me it needs to be done. I found that in the..Maxposition on the control it will have the compressor running all the time. R134a vs. R12 - Griffiths R-12 is no longer used or produced in many countries and remaining quantities have skyrocketed in price. Paul:It is never a waste of my time to chat with someone that understands the problem, and wants to fix it. The flammables have hydrocarbons. The adjusted tension of this spring is the determining factor in the opening and closing of the expansion valve. Welcome to rxmechanic.com. Flush with a garden hose - do not use a high pressure washer - you can bend the fins flat & damage the condensor.B. Also the new quick connect fittings for the high & low side. -------------------------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! 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. In sum, R12 has done more bad than good. In more serious, it could result in cardiac irregularities or death. Fitting a PF condensor is not rocket science, but it requires some planning. Any advice appreciated. Please enter a valid email address for yourself. What is usually sniffed are all the connections in the system: hoses and compressor, condenser, drier, expansion valve and evaporator fittings. That would be the "black death" syndrome. Failure to abide by the EPA regulations can result in expensive fines for either you or your service technician. By using a qualified a/c shop with the proper equipment you odds are in your favor of having the job done correctly the first time. |. However, R12 refrigerants are still used as fire retardants in aircraft and submarines. Carefully study the chart and compare the following: To a large extent, the choice is up to you. With the A/c off hi and lo were both at 105psi. By: james smith underoath; Comments: 0 . Crap! Minor adjustments to the expansion valve and other controls may be necessary for some plans. I'm just trying to help you avoid headaches in the long run. The expansion valve is designed so that the temperature of the refrigerant at the evaporator outlet must have 8 to 12F (4 to 7C) of superheat before more refrigerant is allowed to enter the evaporator. R134a has the chemical formula CF3CH2F and is known as tetrafluoroethane. 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. The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. Hence, let us continue to fix it. R134a and R12 are among the most popular types of refrigerants. Right now you know you have a bit too much, but with a CR4P compressor this is an insurance policy. 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. At 40, it is 35psi, which is a difference of 8.9psi. Please enter a password for your user account. I don't know where it is getting the switch off command, or why the vent temp drops steadily. Since then, the industry standard has been R134a, which is an efficient replacement. R-12 vs R-134a Hose - Pelican Parts Forums I had a 1991 BMW switched to 134a by just changing the low pressure charging valve, flushing and refilling with 134 (maybe with 10% . _____ 2012 E350 2006 Callaway SC560 . 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. R-12 to R-134a Conversion. -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. I put in a new (not reman) compressor (R4 I believe it is) in my merc 240D, new drier, new expansion valve, new o-rings, nylog. -------------------------"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." Here are the basics for converting a system that does not have a charge of R12, its empty. . difference between r12 and r134a expansion valve However, if it is taken close to a fire flame or any electrical heating element, it disintegrates into toxic products. What effect would it have on performance, if any?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. The oil is spread all over your system when it is at rest. 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? Related products. There are three different refrigerants officially sanctioned by the EPA for automotive usage: r-12, r-. Hence, the effect of R12 on global warming is up to 10,000 times higher than carbon dioxide. 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. . The analysis focuses on Coefficient of Performance for . A Comparison Study of the Thermal Performance of R12 and R134a Just had knee surgery yesterday, so I"M not exactly hopping around too well. R12 Expansion Valve with R134A charge? - Maverick Expansion Valve for R134a? | Team Chevelle Should I do the test again with the the aux fan jumpered? How dumb!I will jumper the aux fan and redo the test. All pre-97 XJs use systems with the same basic operating principle, although the parts do change a bit. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? 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. 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. 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. ThanksPaul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. In large application systems, the vapor density of this refrigerant is usually high. $21 . 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. R134a is otherwise called 1,1,1,2 Tetrafluoroethane, Florasol 134a, Freon 134a, Norflurane (INN) or HFC 134a. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. Your decision could be made based on economics, environmental concerns, or both. The cable is adjustable at the valve arm. video clubhouse baseball; nick fairley draft profile; ben davis work pants asia pacific stevie awards 2021. gin, amaretto cocktail. I know this is bad, etc, and deposits on the metal can act as insulators. Recovery & flushing is the only way out of an oil overcharge in your vehicle.B. However, you can convert R12 to R134a by yourself, save money and keep all the tools purchased. The larger line at the expansion valve is the suction line. 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. = R134a Charge Level. Therefore, the R12 refrigerant is illegal, and emitting it is illegal. 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. And I lied about the compressor switches on this car - there are 2 switches on the drier - a temp and a pressure switch. Yes it will work with either Refrigerant! It's actually a reaction with chlorine in the mineral oil that may have been absorbed and leftover from the old R-12. Is that why expansion valves are specific to R12 or R134A? Very interesting! MB has specfic test parameters for performance, but you can always test at max load - doors open fan on highest speed.The oil overcharge looks like a parabolic curve. 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. 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. But as there's not a big difference, people say you can suffice with either. But with an R4, better too much than too little.3) A TXV optimized for 134a will be ok with R12.4) The airflow across the condensor is crucial to good performance. What is a good differential? Its chemical symbol is CH2FCF3. Then again, there are two different expansion valves. Its highest value is 1. 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? Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. The next piece of equipment to track down leaks is a leak sniffer. How is 1234yf different from . Trinary Pressure Switch $ 39.99. I used a full can of evap cleaner. 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. If the system was upgraded by a professional it should have an upgrade sticker. 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. I mean, really a lot. 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. A/C Expansion Valve Replacement Cost. The compressors used by refrigeration plants to compress gas require oil to help lubricate its moving parts. There is a lot of differences between the R12 and the R134a fittings, you can't mistake them. The difference between R12 and r134a is the BTU carrying capability. Amazon.com: 134a Valve That switch should close @ 52c. It runs between the condenser outlet, receiver/drier unit and expansion valve at the firewall. If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? PDF Tecumseh Guidelines for Utilization of R134a R1234yf is more environmentally friendly and has a global warming potential of 4. However, theyre still used in older plants, systems, and the automotive industry. RULES for AOP - Owner Assistance and Contractors, Energy Efficiency and Building Performance Discussion NEW, Carnak Zone/Locked Areas - For Professional Member Only, How To Become a Pro and Rules For Pro Members, Pro Forum: Refrigerants and EPA regulations **NEW, Pro Forum: Residential Refrigeration and Appliances **NEW, Pro Forum: Equipment Recalls and Bulletins **NEW, Pro's Forum: Building Science Discussions, Educational Forums - Open for all in the industry, Welcome to HVAC-Talk's Educational Forums, How to Submit Links, Articles and Quiz Questions, Frequently Asked Questions About Submissions, Physics, Thermodynamics, Fluid Flow and Combustion, Educational, Training & Reference Information, Manufacturer's Technical Information Links, Electrical Theory, Circuits and Electronics, HVACR Equipment, Components & Accessories, Accessories Humidifiers, Air Cleaners, HRUs, Fans, Filters, etc. 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. BTW, I use a stick thermo in the vents and the laser on the condenser. This allows the refrigerant in the condenser to be void of oil particles. and feeds it through an expansion valve. 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. Energy usage: R134a is less efficient in cooling compared to R12. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. Trinary Pressure Switch quantity. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). You do not need to replace the expansion valve in most cases. 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. 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. System has been working fine for a year. difference between r12 and r134a expansion valve 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. Is there a graph? Yep, definately not a meat locker. R12 is used in several applications like low temperature, medium temperature, and high-temperature applications. You either get a system that will function well with R1234yf or get any other type. VerticalScope Inc. All Rights Reserved. Operating Pressure/Temperature Differences The pressure/temperature curves for R-1234yf and R-134a are very similar. 5. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? 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. Its cylinders are colored white. Rules governing changing from the former to the latter differ between countries. It is made up of carbon, hydrogen, and fluorine. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . Safety: R134a is safe to use as its non-flammable and cant explode. The symbol implies that R12 is a composite of carbon, chlorine, and fluorine. This is an electronic tool that sucks in air through a tube and across a sensor. 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. All fans must work at 100% of the OEM rating. These two refrigerants are the older types and are not used in newer refrigeration and air conditioning systems. Is that why expansion valves are specific to R12 or R134A? -------------------------"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." The higher the ambient temperature the higher the high side pressure. The AC usually does not work at all. 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. When I compare parts, 93 uses one part number and 94 has a different part number. They plug all the time. AC R12 to R134A Conversion | MR2 Owners Club Forum Then when it is switched off for a few minutes and then back on, the air cools again. 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. 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. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. Its chemical symbol is CCl2F2. 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. Are you sure you have an R4? Is it exponential, squared? The best oil that runs well with R134a is PAG oil or Polyalkylene Glycol. A/C receiver difference between R12 and R134a? The oil used in R12 and R134a are different and not compatible. 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. In addition, R134a refrigerants are not only used in auto air conditioners, they can be used in freezers, aerosol cans, and refrigerators. By noting the ambient temperature you can look up what the preferred high side pressure should be. 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. Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. 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. 2) Frost on the Vents. When you add fluorescent tracer dye to with the refrigerant oil it helps to track down leaks that push oil out of the system. So to keep things simple and to avoid controversy and politics we have R134a. 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. difference between r12 and r134a expansion valve. That is for the compressor, drier, expansion valve and condenser. 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. 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). . Besides, you have a greaseisel. It slowly gets warmer and warmer in the car, even at highway speeds. shown for the parallel flow, aluminum condenser that is listed. . We mention using ester type refrigerant oil. As noted, measure up front as best as you can to get as close to the aftermarket dim. On this website we are addressing only R134a and not other suggested drop in replacements. R134a refrigerant is lighter than R12. R12 is heavier than R134a and has smaller molecules. Before we mentioned that you can add approximately 5-6 ounces of ester oil to the compressor. The approval is very legal one, governed by the U.S. EPA. Is that reasonable?Vent airflow is good, I think. What is the refrigerant property involved that has caused this? 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. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. Participate in over 40 different forums and search/browse from nearly 3 million posts. Catalog E-1, Thermostatic & Automatic Expansion Valves / Page 1 Table of Contents . If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyers guides, and car and tools comparisons. An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback. Rules governing changing from the former to the latter differ between countries. But, what is considered a good temperature differential across the condensor? 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). Also, it can be used with all types of compressors. R12 is CFC: Even though R12 is one of the most commonly used refrigerants, it is CFC. 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.