R 134A is designed for the high demands of an automobile AC and cannot be used on refrigerators due to pressure differences. 05-25-2017 02:14 AM. Answer: OK, I'll bite. Yes, this was a smokers car. The difference between the two is about 10,000 btu/h. Though - the valve for a 1991 says R12 on it, and for a 1994, it says R-134a. Lasers don't do well on vent temps, a stick thermometer is better in that application. 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. This can be very very expensive. But R22 is almost equally damaging. Discussion in 'Technical' started by Jsarnold, May 25, 2012. 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. Though I have seen em run as cold as 12 deg F. If the thermo switch is malfunctioning. Your average garage that works on a/c on the side probably would not have this. Therefore, its most suitable for both commercial and domestic environments. R12 is used in several applications like low temperature, medium temperature, and high-temperature applications. ambulance tailgate conversion Is there a difference in the expansion valve for R12 as opposed to R-134a? Is checking the temperature of the in and out of the condensor not the easiest way to tell if it is doing a good job or not? Stay home and grill your own steaks and stir your own martini. Superheat you can consider to be the additional amount of heat. However, theyre still used in older plants, systems, and the automotive industry. I put one in my old daily driver '79 Chevy tank (r-12), and it really made a difference. For instance you can evacuate FRIGC FR-12 into a refrigerant recovery bottle that has R134a in it or visa versa. Some 1993 and older R12 systems aren't as 'compatible' as you'd think to switch over. The original expansion valves work very well with 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. 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. . It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. 1) Look Here at the available sizes of PF condensors.2) Go look at your vehicle's condensor & mounting. I have some experience with auto a/c but not too much. R12 is CFC: Even though R12 is one of the most commonly used refrigerants, it is CFC. had writing on the side that said R134a. Components Coils, Heaters, Motors, etc. I had a 1991 BMW switched to 134a by just changing the low pressure charging valve, flushing and refilling with 134 (maybe with 10% . I'm thinking of jumping the temp switch and leaving the fan on to see how it does. Theres no problem with using R134a in a home air conditioning system because it is a hydrofluorocarbon that doesnt cause environmental harm. Energy usage: R134a is less efficient in cooling compared to R12. As noted, measure up front as best as you can to get as close to the aftermarket dim. Thanks for the input. The ARPA Zone/Open Membership Discussion Forums. difference between r12 and r134a expansion valve. You are indeed 20% out of the OEM spec for cooling. The difference really shows up on the high side. Spray it deep, and let it sit for a few minutes. I think the way to go here is1. All fans must work at 100% of the OEM rating. Please enter the name by which you would like to log-in and be known on this site. Moreso, it had been banned. Figure 2 shows the different phases and pressures the refrigerant . 5. Your old hoses of course will not fit. Very interesting! I don't want to be chasing ghosts. . There are R134a specific valves that operate at a slightly different pressure, but not for any "old" automotive application that I'm aware of. But as there's not a big difference, people say you can suffice with either. 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. difference between r12 and r134a expansion valve. 3) A TXV optimized for 134a will be ok with R12. But as there's not a big difference, people say you can suffice with either. Is that why expansion valves are specific to R12 or R134A? In addition, R134a refrigerants are not only used in auto air conditioners, they can be used in freezers, aerosol cans, and refrigerators. R134a systems operate at higher discharge-side pressures than R12, which can cause compressor seals to leak. 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. Can I use the one for the R-12? Thus, when the system is running, condensing the CO2 is not a problem. -------------------------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. It's best to determine on a case-by-case basis while monitoring system pressures and output air temperature. Looks like a couple of things happening here1) 80's vintage Eurocars were not "meat lockers". R134a and R12 are among the most popular types of refrigerants. El juny de 2017, el mateix grup va decidir crear un web deDoctor Who amb el mateix objectiu. difference between r12 and r134a expansion valve why is miles raney not on homestead rescue June 21, 2022. manila mayor candidates 2022 James10952001. 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. To prevent refrigerant loss you should consider replacing your old hose lines with barrier type hose. Also, since R134a uses synthetic oil, it has a low global warming potential, unlike R12 which uses mineral oil which poses a negative environmental impact. In practice this means that the car can overheat and the aux fan will stay off! Kommentare . Biggest you can fit in there is best. 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. 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. Below are the major differences between R134a and R12: The chemical composition of R12 and R134a differ. Usually, mechanics charge around $200 for conversion. It won't be optimal, though. This refers to BTU's (heat) moved per pound of refrigerant moved. Replacement expansion valve for R134a or R12 A/C refrigerants, with O-ring connections. For instance at 25 F the pressure of R-12 is 24.6 PSI and the pressure of R-134a is 22.1 PSI. The oil used in R12 systems is not compatible with R134a refrigerant. Bohica, I appreciate your help with this. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. difference between r12 and r134a expansion valve. look at the difference! 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. The system will be checked for gross leaks while under vacuum. 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. Is that why expansion valves are specific to R12 or R134A? 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. Very nice! That switch should close @ 52c. Also, it can be used with all types of compressors. Here are the basics for converting a system that does not have a charge of R12, its empty. Condensers designed to release greater amounts of heat help to expel the greater amount of heat which R134a removes from the cars interior. Its cylinders are colored white. R12 Expansion Valve = 201 830 06 84 R134A Expansion Valve = 201 830 04 84 Is there a difference after all? However, it was found to be a very bad gas for the environment. Bookmarks: Digg; del . Some cars have both an engine coolant temp switch & a refrigerant temp switch, others only the refrigerant switch. Why wait for 200f on the engine coolant to start the fan? They can be mounted quite easy,and there is a mounting kit that helps to hang it. Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. Before we mentioned that you can add approximately 5-6 ounces of ester oil to the compressor. The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. The current expansion valve is FF - 1/4 - C. Is it neccesary to replace this valve? I'm just trying to help you avoid headaches in the long run. R134a has the chemical formula CF3CH2F and is known as tetrafluoroethane. Not osmosis, but you know what I mean). Performance doesn't seem to have improved. Besides, its technology has been tested and trusted. Then at least I'd know really where I am on it. Table 1 summarizes the technical characteristics of three potential R134a alternatives. 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 ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? What effect would it have on performance, if any? But R22 is almost equally damaging. 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. About four or five years ago, I guy with an MB came here with the same problem, that tread was over six pages long. The P H and T cond,sat of the HR12 at a T oa of 40 C were higher than that of the R134a, resulting in a higher P e than that for the R134a. 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. 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? We say generally because the vehicle manufacturer may have a formula already worked out for the R134a conversion process. Disconnect the two hose lines to the compressor, protect the ends from getting dirty. Any ideas from the info above? The primary function of the design engineer is to make things difficult for the fabricator and impossible for the serviceman. Different correction factors are applied to other refrigerants. A discussion of the relationship between valve capacities and superheat set-tings can be found in Bulletin 10-9. Next I'll jumper the aux fan. 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. Safety: R134a is safe to use as its non-flammable and cant explode. The best replacement for R134a is R1234yf, while R12 refrigerant replacement was R134a. I dont know why the cost difference between compressors is so huge, though. Below are the major differences between R134a and R12: Chemistry The chemical composition of R12 and R134a differ. Unfortunately, the oil only mixes with the refrigerant as a liquid. This is because R134a. 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. In sum, R12 has done more bad than good. difference between r12 and r134a expansion valve. So that indicates it is cooling well there doesn't it? The value of carbon dioxide is 1. I've got a ball valve I'm going to put in the coolant line before the coolant goes through the firewall to the core. This chart has a column of ambient (outside) air temperatures on one side and a corresponding range of high side pressures on the other side. Refrigerators generally utilize R22, R32, or 410A-based coolants as their cooling agent. Concentration level: The R134a vapor dilutes the oxygen concentration in the air to a low level, thereby causing harm. In cases such as this, the required capacity value of the expansion valve with R134a is reduced by 30% (correction factor 1.42). So, instead of using R12, other better options include R401b, R134a, R401a, etc. "Jerky Locker" LMAO I am using that one in the future!Florida = BUGS! R-12 expansion valves can be re-used, but will not be as efficient as R-134a specific ones because of the slightly different pressure specs of R-12 vs. R-134a. It is also used in automotive car conditioning and the plastic industry. Generally, the new amount is 75-85% of the quantity advised by the manufacturer. Plus, not releasing the chemical into the air is morally justifiable. Compared with the cost-performance ratio, R507 is 30-40% . We, the Rxmechanic team, have presented a well-detailed comparison of R134a vs. R12. After the optimum refrigerant charge is determined the car should be test driven to check for performance of the system. 2) Frost on the Vents. Interestingly, theres one oil type that works perfectly with both types of refrigerants. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . This is the part that controls the system pressures. 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. The cure is to use the newer R134a compressors is sealing washers that are different thickness. You should keep in mind that recharging your air conditioner improperly could result in more serious damage. Is there a graph? Also called the orifice tube. Ask Our Pros-Owner Assistance - NO DIY advice will be given. R12 and R134 are of different chemistry. Hence, let us continue to fix it. This is due to many facts: R134a refrigerant is about 10% less efficient in moving heat than R12! With new R12 no longer being manufactured, the market price soared to $100/pound. SO here's my question. The experimental values of C.O.P.H obtained with the R134a/ester charge were 20.2% 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. system of 0.33 TR and refrigerant used was R12. 1.5 ounces - hmmm. Therefore, the R12 refrigerant is illegal, and emitting it is illegal. Is there a source of valves by, say, eaton number? The only difference I can imagine would be the recharge connection. The mechanical fan & clutch should be checked as well. a 50f delta across the condensor is good, but I suspect that is an idle reading. ESP when a compressor has frozen. 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!) B. R12 is heavier than R134a and has smaller molecules. Trinary Pressure Switch $ 39.99. To ensure the right charge, you must fill the new system with between 75 and 85% of the factory-set capacity for optimal cooling. In a comparison between R12 vs R134a vs R1234yf, R1234yf will pass as the best refrigerant. Add to cart. . R-134a is widely believed to be the most acceptable R12 substitute. However, R134a is better than R12. A lower GWP alternative to R-134a had to be found and thus we have the new 1234yf. It cycles on off in med (or low for that matter)Gotta tell ya. A York oil capacity is listed as "6.5 to 9.6 ounces". A/C systems designed to use R-12 will cool best when charged with R-12 refrigerant. Took me a while to figure that one out, and how to say that. If you have 10 ounces of oil in the system, that is contributing to the poor performance as well. I'm not sure. Is it exponential, squared? Theres no doubt that R12 refrigerant is one of the first compounds manufactured for the air conditioning and refrigeration world, but it had to be banned. The smoking question & vent airflow indicate that the evaporator is fairly clean - and you are aware of the importance of that.The heater valve stops the flow, but there is always some conduction heating. of refrigerant insulation tape. The analysis focuses on Coefficient of Performance for . R12 is highly destructive to the earths ozone layer. Its chemical symbol is CCl2F2. You'll get marginally better performance out of the change as the expansion valve is matches the refrigerant characteristics. 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. This leads me to labor over every small decision. Please enter a valid email address for yourself. If not, you just don't know unless a test is performed. Look at where the lines will end up. Mark Baker R-401b is the mixture by weight of 61% R22, 11% R-152a and 28% of R-124. R134a and R12 are both refrigerants used in vehicle air conditioning systems. Participate in over 40 different forums and search/browse from nearly 3 million posts. The only difference I can imagine would be the recharge connection. Fitting a PF condensor is not rocket science, but it requires some planning. 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). 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. We've updated our forums!Click here to visit the new forum, Year: 1991Make: Jaguar Model: XJ6Engine Size: 4.0. BTW, I use a stick thermo in the vents and the laser on the condenser. Its among the greenhouse gases and will keep adding the current problem of heat not leaving the earths atmosphere. maintain the A/C of older cars. We sometimes use a relay switched from the compressor clutch to run fans. R12 was once used in many air conditioning units as a refrigerant or cooling agent. Big . of coiled cap tube on VCR system with R134a. R134a. I could easily be over at least 2 - 3 ounces over on the oil. This refers to BTU's (heat) moved per pound of refrigerant moved. Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. and recharged with mineral oil and 2.2 lbs R12. You can also check the Aux fan in your case. Bad Car A/C Expansion Valve Symptoms. Edited: Tue July 17, 2007 at 3:25 AM by bohica2xo, I believe there is only one switch - the refrigerant switch. Therefore, the higher the factor of the chemical (compound), the greater its effect on global warming. We recently created this blog site to enable us to share our knowledge with other automotive mechanics and car owners. We mention using ester type refrigerant oil. If the charge is low the compressor will cycle on/off in the max AC position. 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. 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. Helical and Serpentine coils. It's not just the poor performance - the cooling just stops working after a while. 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 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. Since 2010, all home AC systems manufactured use a refrigerant like R134a that has zero ozone depletion potential (ODP). Like say half a can or so recharge come springtime warm weather or something. This kit comes complete with Expansion valve, o-ring kit, and 1ft. 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. Even with proper fan operation, missing seals & air dams can effect condensor effeciency. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. Yes, I don't trust the heater valve either. CR4P). and he synthesized R-134a in 1936, 5 years after R-12 was . Super heats are so close, it should not be a major concern.-------------------------The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government. These differences in the valve size can be attributed to the correlation of the cooling capacity with the enthalpy difference and the mass flow, which in . 4 Stars & Up & Up; 3 Stars & Up & Up; 2 Stars & Up . Ensure you contact a professional mechanic to do the work for you so you dont end up incurring more costs for yourself. The R134a compressor has a 1/8" step in on the high side port. In a car ac, using this type of freon 20 years ago was difficult. is good, then I should be looking elsewhere? In short, NO! I bought a relay to put on it connected to the compressor clutch. Lets take you through the advantages, disadvantages, and differences of these two refrigerants a detailed comparison including R12 vs R134a performance. The common problem when converting from R12 to R134a is lack of knowledge or equipment. It is made up of carbon, hydrogen, and fluorine. Right now you know you have a bit too much, but with a CR4P compressor this is an insurance policy. 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. 42 (at best) w/ 134A in 2000 isuzu trooper. R12 can move more heat than r134 so when it isn't very hot and the system isn't maxed out you wont be able to tell the difference but when its 110 out and the inside is 140 R12 will cool the cabin temp faster. I'm curiousSo there is work to do, ie performance should be able to be improved. Recharge the compressor with a/c ester oil and a tracer dye. We consider the the various types alternative refrigerants that are illegal or not approved to be in two sectors: non-flammables and flammables. B. Hot coolant migrates up through the core by convection (is that the word? Trinary Pressure Switch quantity. Its chemical symbol is CH2FCF3. Failure to abide by the EPA regulations can result in expensive fines for either you or your service technician. (On firewall where A/C lines go into cab.) With the knowledge of the differences, youll be able to draw a comparison between R12 vs R134a efficiency. compressor, condenser, evaporator and expansion valve are specifically designed for use with R134a. Operating Pressure/Temperature Differences The pressure/temperature curves for R-1234yf and R-134a are very similar. shown for the parallel flow, aluminum condenser that is listed. Skin contact: If the R134a (liquid) comes in contact with your skin, it could cause a burn. It is made up of carbon, hydrogen, and fluorine. R12 is simply too expensive for a 25+ year old A/C system. In more serious, it could result in cardiac irregularities or death. The compressors used by refrigeration plants to compress gas require oil to help lubricate its moving parts. Once you have replaced the OEM condensor with a PF unit, you will need to make custom hoses to mate with your OEM system. R12 systems used mineral oil, but unfortunately mineral oil doesn't dissolve in R134a. Whether R134a performs as well as R12 in any given a/c system depends upon system components and the amount of R134a used. 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. It does not "pool" to any degree in a large amount anywhere. Make sure to get the R12 EXP valve if that is the way you go. I know this is bad, etc, and deposits on the metal can act as insulators. Use a drop light in the engine bay, and check the air path from the front of the car at night. It runs between the condenser outlet, receiver/drier unit and expansion valve at the firewall. Its chemical symbol is CH2FCF3. Most of all the differences gravitate to longevity, functionality, and safety. The problem with not being an expert is that you don't know what is important and what's not. At this time you can still find R12, but, because it is no longer produced, availability is limited to current inventories and the price per pound is greater than R134a. 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. R-12 to R-134a Conversion. 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. #19. But as there's not a big difference, people say you can suffice with either. You do not have to split up the 5-6 oz of oil and add it to each component, just simply put it all in the compressor as it will move throughout the whole system once the system is operational. 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. What is needed? we convert older systems where i work all the time and they work fine. 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. Just because the radiator does not boil people assume that the cooling system is ok. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. 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.