Bottom line, R134a simply doesn't cool as well as R12. R-134a is widely believed to be the most acceptable R12 substitute. Generally the system will be initially charged with approximately 80% to 85% of the original amount of R12, using R134a. 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. That's a lot isn't it? Then when it is switched off for a few minutes and then back on, the air cools again. This is not to say that one of these small retro-fit kits cant be used, however to be used wisely. By noting the ambient temperature you can look up what the preferred high side pressure should be. 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. difference between r12 and r134a expansion valve. Minor adjustments to the expansion valve and other controls may be necessary for some plans. . Big . 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. 5. Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). 4.R404A R134a increased mass transfer resistance to reduce the transmission chamber heat coefficient, while R507 heat transfer coefficient is higher than R404A. Then again, there are two different expansion valves. Differences between R-12 and R-134a systems: 1. R134a vs R12 refrigerant? Like say half a can or so recharge come springtime warm weather or something. This works when the R12 charge specification is listed in pounds. 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. If the charge is low the compressor will cycle on/off in the max AC position. If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? The difference between the two is about 10,000 btu/h. R134a systems operate at higher discharge-side pressures than R12, which can cause compressor seals to leak. difference between r12 and r134a expansion valve. I dont know why the cost difference between compressors is so huge, though. We sometimes use a relay switched from the compressor clutch to run fans. Theres no problem with using R134a in a home air conditioning system because it is a hydrofluorocarbon that doesnt cause environmental harm. I'll put the relay on for that. I think the way to go here is1. Blows pretty hard on full. There is only a temperature switch on these cars as far as I recall, and it just switches on the aux fan. I recommend replacing the expansion valve when you do the swap. _____ 2012 E350 2006 Callaway SC560 . 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. So that indicates it is cooling well there doesn't it? Failure to abide by the EPA regulations can result in expensive fines for either you or your service technician. 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. Do a pre-inspection and then Evacuate (vacuum down) the system, the longer the evacuation the better but there is a point of diminishing return, 2-3 hours is generally very good. Discussion in 'Technical' started by Jsarnold, May 25, 2012. Ensure you contact a professional mechanic to do the work for you so you dont end up incurring more costs for yourself. 2) Frost on the Vents. 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. Hot coolant migrates up through the core by convection (is that the word? It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. 3) A/C Compressor Always On. 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. Usually, mechanics charge around $200 for conversion. Also, they are mostly used in refrigeration and automotive air conditioning systems. Generally this works well for the whole system. Look deep into the fins. Biggest you can fit in there is best. Also, R134a cylinders are light-blue in color. Rules governing changing from the former to the latter differ between countries. The mechanical fan & clutch should be checked as well. I remember I had the wrong seals and it leaked some oil, so I put some more in.Bohica - I tested the pressures. It's not just the poor performance - the cooling just stops working after a while. With the knowledge of the differences, youll be able to draw a comparison between R12 vs R134a efficiency. Yep, definately not a meat locker. Even if the system leaks, repairing the leaks and recharging it with R-12 is usually the best repair alternative. 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. 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. Performance doesn't seem to have improved. And no, you cannot "drain' excess oil out. R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. 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. 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. link to How to cut off a Catalytic Converter. I had to vaccum the system for 2 hours and recharge 4 oz of PAG oil plus 36 oz of 134A freon (3 cans). 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. When the temperature is reduced to-7C or below, the plants ability to cool the airdrops significantly. To bless the system the technician should attach a R134a sticker somewhere in the engine compartment to note the car is using R134a. 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. If you have a perfectly operating system using R12 you do not have to drop what you are doing and convert to R134a. 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. 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. I've done the FSM test and with 81F ambient, the vent should be 50F. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. 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. Vent temperatures slowly go down to around 50F with hi speed driving. 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!) The reason is that the vehicles, for instance, manufactured currently configure the engine for R1234yf refrigerant, making no provision for replacement. When the sensor detects the refrigerant leak the sniffers lights glow and the sniffer makes a noise. I'll report back on the aux fan on performance next. By after changing just about everything, he got what was termed, satisfactory cooling. Bookmarks: Digg; del . The good thing is that after you convert to R134 you can top off the system easily and cheaply. R134a refrigerant is lighter than R12. In cases such as this, the required capacity value of the expansion valve with R134a is reduced by 30% (correction factor 1.42). The first vehicle that used the R1234yf refrigerant was the 2013 Cadillac XTS. But, what is considered a good temperature differential across the condensor? Kommentare . This is a great space to write long text about your company and your services. Why wait for 200f on the engine coolant to start the fan? R134a refrigerant is about 10% less efficient in moving heat than R12! Very interesting! evarporator, expansion valve plus flushing out the full system and replacing all the o rings. Could that be screwing up the systems performance?Anyway, when I installed the system, the new TXV (is that short for expansion valve?) 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. I just got some hi/lo side gauges so I'm going to take readings, if they are needed. B. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. July 3, 2022July 3, 2022. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? Electric fans do wear out. Even though their common major function is to cool the system, they have many differences. I'm having the same concern. R134a refrigerant fittings are different size. 10,000BTU conduction heating? Using R134a requires that Polyolester (POE) lubricant must be used in the compressor. But R22 is almost equally damaging. This is because R134a. 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. For instance you can evacuate FRIGC FR-12 into a refrigerant recovery bottle that has R134a in it or visa versa. 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. But some types of PAG do not mix well with the old residual R12 mineral oil left in the system components whereas ester does mix very well. 42 (at best) w/ 134A in 2000 isuzu trooper. 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. The system will be checked for gross leaks while under vacuum. 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. Generally, the new amount is 75-85% of the quantity advised by the manufacturer. 30 deg is pretty coldSystems generally run between 40 and 43 deg. Talk about what services you provide. by | Jun 21, 2022 | what is the most accurate latin translator | burlington iowa arrests | Jun 21, 2022 | what is the most accurate latin translator | burlington iowa arrests The exact amount will vary with each car. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. A/C Expansion Valve Replacement Cost. Answer: OK, I'll bite. absorb by the evaporator to insure all liquid refrigerant entering the evaporator. R134a is called tetrafluoroethane (HFC). I think so. I don't know where it is getting the switch off command, or why the vent temp drops steadily. 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. R12 is CFC: Even though R12 is one of the most commonly used refrigerants, it is CFC. This means that it has a high potential of causing depletion to the ozone layer. Als nostres webs oferimOne Piece,Doctor Who,Torchwood, El Detectiu ConaniSlam Dunkdoblats en catal. You may need to adjust the valve in a bit to get desired superheat. 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. To prevent refrigerant loss you should consider replacing your old hose lines with barrier type hose. Expansion Valves Catalog E-1, July 2012. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. We've updated our forums!Click here to visit the new forum, Year: 1991Make: Jaguar Model: XJ6Engine Size: 4.0. You either get a system that will function well with R1234yf or get any other type. Spray it deep, and let it sit for a few minutes. Thus, when the system is running, condensing the CO2 is not a problem. Stopleak is also risky. -------------------------"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." Do I leave the orignal condensor in, etc?Thanks. Figure 2 shows the different phases and pressures the refrigerant . R12 contains a chemical called chlorine that destroys the ozone layer, thereby causing potential environmental risk. Recovery & flushing is the only way out of an oil overcharge in your vehicle.B. The adjusted tension of this spring is the determining factor in the opening and closing of the expansion valve. 5. Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. Helical and Serpentine coils. A. Pressure/temperature plot of R134a vs. R12 is shown in figure 1. The catalytic converter is an essential component of your car's emission system that helps save the environment from harmful emissions. I'm doing one thing at a time so I know what the cause was. sparkee said: Thanks for the Service Bulletin. If 50 degrees across the cond. Flush with a garden hose - do not use a high pressure washer - you can bend the fins flat & damage the condensor.B. Safe but sorry! The cure is to use the newer R134a compressors is sealing washers that are different thickness. The typical scenario here is when the car owner buys an inexpensive retro-fit kit from the local auto parts store. You can use the R134a retrofit capacity chart for this purpose. The system has been previously converted to R-134a. They plug all the time. The oil used in R12 and R134a are different and not compatible. 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. 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. R12 is heavier than R134a and has smaller molecules. VerticalScope Inc. All Rights Reserved. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? Large temperature difference between expansion valve inlet and outlet oReplace expansion valve Air . -------------------------"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 R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. 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. By: james smith underoath; Comments: 0 . R12 and R134 are of different chemistry. Any suggestions, or do you need to know the hi/lo readings? Stay home and grill your own steaks and stir your own martini. The R134a compressor has a 1/8" step in on the high side port. The difference really shows up on the high side. Make sure to wear safety gloves, goggles, and shoes when theres a possibility of exposure to the chemical (R134a). Stability: RR12 doesnt disintegrate even under extreme operating conditions. The ozone depletion potential of a chemical is a factor that shows the level of degradation itll cause to the ozone layer that surrounds and secures the earth from harmful radiation. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. 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. Unfortunately, the oil only mixes with the refrigerant as a liquid. Temp switch works the aux fan. Is it exponential, squared? Paul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. If the system was upgraded by a professional it should have an upgrade sticker. After the optimum refrigerant charge is determined the car should be test driven to check for performance of the system. But I don't want to waste your time. Inasmuch as R134a has a global warming potential thats over 1000 times more threatening than carbon dioxide, its better than R12. Quick View. Gnats & mosquitos will clog deep. Add to cart. Thus, when the system is running, condensing the CO2 is not a problem. Hopefully after you have read this entire page you will have enough information to determine which type of refrigerant is best for you. Its chemical symbol is CH2FCF3. Bad Car A/C Expansion Valve Symptoms. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. James10952001. R134a is the most widely accepted alternative automotive refrigerant used to replace R12. Can I just use an adapter and save $200? A/C systems designed to use R-12 will cool best when charged with R-12 refrigerant. and recharged with mineral oil and 2.2 lbs R12. It is mixed with the freon for the most part, and does accumulate in all components in small amounts. Get to the point where I can walk without crutches2. 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. June 21, 2022 difference between r12 and r134a expansion valve . My turn to LOL - greasiesel! asia pacific stevie awards 2021. gin, amaretto cocktail. A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . Post photos, respond to polls and access other special features. In addition, R134a refrigerants are not only used in auto air conditioners, they can be used in freezers, aerosol cans, and refrigerators. ing the expansion valve, a maximum opening superheat of 7F, and a standard factory air test superheat setting. Have a look in the FAQ Section, and look for "Fan clutches & testing them". Comparatively, larger R134a molecules should take more space, and a smaller amount might be required. Rules governing changing from the former to the latter differ between countries. I have just bought gauges. The butylcellusolve or the citrus solvent will dissolve the carcass in a few minutes. R12 was once used in many air conditioning units as a refrigerant or cooling agent. 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. Disconnect the two hose lines to the compressor, protect the ends from getting dirty. Also called the orifice tube. Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. Recharge the compressor with a/c ester oil and a tracer dye. 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. Besides, its technology has been tested and trusted. With new R12 no longer being manufactured, the market price soared to $100/pound. 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. Expansion Valve. For R12, its mineral oil. If it splashes inside the eye, it could lead to a serious eye problem. The bad thing is I don't know what to do about it. 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. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyers guides, and car and tools comparisons. It is made up of carbon, hydrogen, and fluorine. Is there a difference in the expansion valve for R12 as opposed to R-134a? The higher the ambient temperature the higher the high side pressure. And I lied about the compressor switches on this car - there are 2 switches on the drier - a temp and a pressure switch. Make sure visiually that no large gaps exist that would allow the air to bypass the condensor on the way to the radiator.B. The #1 question asked by NEW MEMBERS. Paul:A 1983 240D should have a York compressor on an OEM system. R12 and R22 are both now banned by the EPA in the United States. R404a for freezing of product. Look at where the lines will end up. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. 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. Condensers designed to release greater amounts of heat help to expel the greater amount of heat which R134a removes from the cars interior. B. The larger fitting goes on the discharge port and the smaller fitting goes on the suction line or compressor inlet / suction port. The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. 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. How an A/C Expansion Valve Works. Is there a source of valves by, say, eaton number? ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. ambulance tailgate conversion This allows the refrigerant in the condenser to be void of oil particles. Then at least I'd know really where I am on it. With R134a you do not rely on the site glass. -The amount of R-134a needed will typically be 80-90% of the R-12 charge. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores. 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. Best for varieties of operating conditions: Its boiling point is -21.6 Celsius. (On firewall where A/C lines go into cab.) It's actually a reaction with chlorine in the mineral oil that may have been absorbed and leftover from the old R-12. -------------------------"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." Below are the major differences between R134a and R12: The chemical composition of R12 and R134a differ. R12, on the other hand, is called chlorofluorocarbon (CFC). So, instead of using R12, other better options include R401b, R134a, R401a, etc. It won't be optimal, though. You do not want to exceed the systems high side recommendations. difference between r12 and r134a expansion valve why is miles raney not on homestead rescue June 21, 2022. manila mayor candidates 2022 In 1994 they switched from R-12 to R-134a. Not osmosis, but you know what I mean). and he synthesized R-134a in 1936, 5 years after R-12 was . 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? That would be the "black death" syndrome. Please enter the name by which you would like to log-in and be known on this site. 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. A lower GWP alternative to R-134a had to be found and thus we have the new 1234yf. The newer valves and switches will work with both refrigerants. As an example, let's say the R12 charge specification is listed at 2 lbs. I mean, really a lot. Heres R12 vs. R134a pressure chart. Use a drop light in the engine bay, and check the air path from the front of the car at night.