So you could likely put off buying those new hoses just a bit longer if you wanted. Inhalation of vapor: Inhaling a large amount of R134a vapor can lead to drowsiness, temporary nervous system depression, and lethargy. Put a relay on the compressor clutch to the aux fan (I like that idea - makes a lot of sense)How does that sound? 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. 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. Energy usage: R134a is less efficient in cooling compared to R12. I have the original (R12) style expansion valve in the Maverick AC system. we convert older systems where i work all the time and they work fine. 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. Participate in over 40 different forums and search/browse from nearly 3 million posts. Carefully study the chart and compare the following: To a large extent, the choice is up to you. Thread starter goldNSX; Start date 1 August 2009; Tagged . ambulance tailgate conversion My turn to LOL - greasiesel! Since 2010, all home AC systems manufactured use a refrigerant like R134a that has zero ozone depletion potential (ODP). I could easily be over at least 2 - 3 ounces over on the oil. Table 1 summarizes the technical characteristics of three potential R134a alternatives. As for R134a and R1234yf, theres no room for conversion. Still, I have some simple green, so may as well give it a go. It is possible I have 10 ounces (250 ml) in the system. PaulJerky King -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. R12, on the other hand, is called chlorofluorocarbon (CFC). The crossover point is approximately at 64F. The mechanical fan & clutch should be checked as well. 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. In this study, without the need for major modifications to the bus air conditioner, the variation of the ejector dimensions according to different parameters has been investigated in the case of using the R1234yf, R1234ze(E), or R600a refrigerants, which may be a substitute for R134a as a refrigerant due to . J.Harris said: Or if you want to do it like they do in Mexico you can use propane, it's an excellent refrigerant but highly flammable. The original CFC expansion valve used for R12 needs to be replaced with an HFC one for 134a to feed the evaporator correctly. Questions About Becoming A Professional Member? Tech Talk - Differences between R-1234yf and R-134a - FJC Inc CLUTCH CYCLING SWITCH. If 50 degrees across the cond. At the time I thought nothing of it, but now I am thinking maybe that is contributing to the system not working as well as it could. The exact amount will vary with each car. evarporator, expansion valve plus flushing out the full system and replacing all the o rings. R12 was once used in many air conditioning units as a refrigerant or cooling agent. Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. If your car does not have a high pressure cut-out switch in the AC system then youll need to have one installed (call us if you need help). We say generally because the vehicle manufacturer may have a formula already worked out for the R134a conversion process. It runs between the condenser outlet, receiver/drier unit and expansion valve at the firewall. You will be fine with a 134a-compatible TXV running R12. The sticker typically has a place to note the amount of refrigerant used, the type of oil and amount of oil, the technicians sign off or name and the date of the conversion. I have a laser temp reader, and it says the temps going into the condensor are up to 160F - coming out it is always around 110 or so. Nice to use new gadgets! The OEM spec is 2300 rpm @ 12.6v (engine stopped fully charged battery). R12 and R22 are both now banned by the EPA in the United States. 10,000BTU conduction heating? 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. In the automotive world, the replacement for R12 was R134a. According to Wikipedia, There is such a thing as "r132a" (1,1-Dichloro-2,2-Difluoroethane), however there is no indication of it being a commercially produced refrigerant. Theres no problem with using R134a in a home air conditioning system because it is a hydrofluorocarbon that doesnt cause environmental harm. look at the difference! What effect would it have on performance, if any? 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. Inasmuch as R134a has a global warming potential thats over 1000 times more threatening than carbon dioxide, its better than R12. 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. They would then make short "jumper hoses" to connect to the existing stock hoses, refit your old fan if there is a "pusher" fan, and recharge to specs. Welcome to rxmechanic.com. Bottom line, R134a simply doesn't cool as well as R12. The good thing is that after you convert to R134 you can top off the system easily and cheaply. Low refrigerating effect per pound: In comparison to other refrigerants, the refrigerating effect of R12 per pound is low. It was later found that R-134a had a very high Global Warming Potential, or GWP, number. R404a is a zeotropic blend with a temp glide , because of the mixture of 2 or more refrigerants. But as there's not a big difference, people say you can suffice with either. It's helluva humid and hot here in north florida, and I drive around all day for my job. -------------------------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. The value of carbon dioxide is 1. I found that in the..Maxposition on the control it will have the compressor running all the time. After the optimum refrigerant charge is determined the car should be test driven to check for performance of the system. Some compressor manufacturers or OEMs suggest PAG type oil for R134a. Biggest you can fit in there is best. Whenever its exposed to the environment, it changes to a gas. You will be fine with a 134a-compatible TXV running R12. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. On the other hand, R12 has a global warming potential of 10,910. Its cylinders are colored white. Is there a difference in the expansion valve for R12 as opposed to R-134a? . A lower GWP alternative to R-134a had to be found and thus we have the new 1234yf. This works when the R12 charge specification is listed in pounds. This refers to BTU's (heat) moved per pound of refrigerant moved. Besides, you have a greaseisel. Use a drop light in the engine bay, and check the air path from the front of the car at night. Look deep into the fins. After the system has been tested out it should be checked for leaks. The oil is spread all over your system when it is at rest. Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. If you you dont have the free time to play then you are better off to pay a technician. Debug the condensor (I am a computer nerd after all!)3. Its chemical symbol is CCl2F2. 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. Just had knee surgery yesterday, so I"M not exactly hopping around too well. -------------------------Just another brick in the wallHad a little mule I fed him castor oil and every time he jumped the fence he fertilized the soil, The older expansion valves were filled with the refrigerant they were used with, the replacement valves (today) are filled with a different chemical to work with both refrigerants..Hope this helps-------------------------ChickEmail: Chick---------------------------------------------Freedoms just another word for nothing left to lose, I believe the optimum supercool setting will vary slightly between an expansion valve for an R12, as compared to R134a, system. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. 3) A/C Compressor Always On. The higher the ambient temperature the higher the high side pressure. If you are replacing other system components, such as condensers, driers or hoses, you may need to add more a/c refrigerant oil to the system. It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. 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. Most importantly, the oil used in the plant must always be compatible with the refrigerant used. Expansion Valves Catalog E-1, July 2012. Large temperature difference between expansion valve inlet and outlet oReplace expansion valve Air . 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. 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. With the oil leaking out and being told all sorts of things about how these compressors don't have a sump etc, I wanted to be on the safe side. The aux fan didn't switch on though and I didn't check the high side temperature. R12 and R22 are both now banned by the EPA in the United States. 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. Therefore, its most suitable for both commercial and domestic environments. how to get to disney springs from boardwalk / bb dakota plaid jacket canada / difference between r12 and r134a expansion valve. But I don't want to waste your time. 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. I dont know why the cost difference between compressors is so huge, though. . ). 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. PDF COMPARISON OF Rl34a AND R12 REFRIGERANTS IN A VAPOUR - AIVC They plug all the time. Or is there always room for improvement, the more the merrier. Discussion in 'Technical' started by Jsarnold, May 25, 2012. 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. Later model cars that come with 134A will have 134A only connectors. Recomanem consultar les pgines web de Xarxa Catal per veure tota la nostra oferta. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores. I cleaned the evap as best I could, if that is what you are getting at. ing the expansion valve, a maximum opening superheat of 7F, and a standard factory air test superheat setting. Your average garage that works on a/c on the side probably would not have this. Recovery & flushing is the only way out of an oil overcharge in your vehicle.B. Helical and Serpentine coils. I don't know where it is getting the switch off command, or why the vent temp drops steadily. 5. 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. With new R12 no longer being manufactured, the market price soared to $100/pound. This refers to BTU's (heat) moved per pound of refrigerant moved. difference between r12 and r134a expansion valve. 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. 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. Components Coils, Heaters, Motors, etc. The name of the oil is Polyol Ester (POE). The cure is to use the newer R134a compressors is sealing washers that are different thickness. R134a is called tetrafluoroethane (HFC). 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. Its chemical symbol is CCl2F2. 2001-2023 Griffiths Technical Inc. All Rights Reserved. Took me a while to figure that one out, and how to say that. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. However, take note that R134a refrigerants are manufactured specifically for automotive air conditioners. 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. Spray it deep, and let it sit for a few minutes. 4.3 out of 5 stars 491. By after changing just about everything, he got what was termed, satisfactory cooling. 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. June 21, 2022 difference between r12 and r134a expansion valve . In a comparison between R12 vs R134a vs R1234yf, R1234yf will pass as the best refrigerant. 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. So to keep things simple and to avoid controversy and politics we have R134a. The first vehicle that used the R1234yf refrigerant was the 2013 Cadillac XTS. The MB chart shows 360 psi with R12 in some conditions. #4. Effects of alternative refrigerants on the ejector dimensions for 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. Also, R134a cylinders are light-blue in color. When I compare parts, 93 uses one part number and 94 has a different part number. The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. I've straightened the fans I can and sprayed simple green on it, let it soak then hosed it down well. Yes, this was a smokers car. Unfortunately, the R12 refrigerant doesnt always blow cold air. This is because R134a. Use strips of foam to couple the two heat exchangers if necessary.B. 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. Even with proper fan operation, missing seals & air dams can effect condensor effeciency. 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. Whether R134a performs as well as R12 in any given a/c system depends upon system components and the amount of R134a used. The next piece of equipment to track down leaks is a leak sniffer. The typical scenario here is when the car owner buys an inexpensive retro-fit kit from the local auto parts store. The compressors used by refrigeration plants to compress gas require oil to help lubricate its moving parts. I don't think it has any air dams or seals, I'll check to make sure. R134a refrigerant fittings are different size. Please enter a password for your user account. At this point it is time to make an appointment with the a/c shop. It's not just the poor performance - the cooling just stops working after a while. Here are the basics for converting a system that does not have a charge of R12, its empty. The whole trick is to sit there in those steam boxes and not perspire, it's vulgar to perspire when driving on public roads.If you want esteem, drive an MB, if you want comfort with 60*F interiors in a 125*F environment, get a Caddy. 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. Rules governing changing from the former to the latter differ between countries. 1.5 ounces - hmmm. These two refrigerants are the older types and are not used in newer refrigeration and air conditioning systems. 1) Warm Air From Vents. I'm just trying to help you avoid headaches in the long run. is good, then I should be looking elsewhere? The condenser water inlet temperature and flow rate are controlled with the use of a . All fans must work at 100% of the OEM rating. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. Since you will be using less R134a than R12 you do not want to rely on the driers site glass to determine if the system is full. R134a systems operate at higher discharge-side pressures than R12, which can cause compressor seals to leak. You may have heard of a friend that did the job himself with borrowed equipment and 12 or 16 ounce cans of refrigerant. The oil used in R12 systems is not compatible with R134a refrigerant. R134a is NOT less efficient than R12 Actually R134a is more efficient. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. 5. Refrigerators generally utilize R22, R32, or 410A-based coolants as their cooling agent. Post photos, respond to polls and access other special features. The original rubber a/c hose lines in your car will leak out R12 through the hoses lining. What is the refrigerant property involved that has caused this? 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). R134a requires a different oil. The system will be checked for gross leaks while under vacuum. 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. Then at least I'd know really where I am on 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. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. The expansion valve(Tx) is in the car at the inlet line to the evaporator with compressors you best get advice from an ac specialist shop as the differences could be the gas that it pumps some systems use R12 and others use R134a or later gas yes R1234yf Freon gas can be replaced by R134a; the newer systems were designed with this in mind so no, there will be no damage to the compressor but some time in . Vent temperatures slowly go down to around 50F with hi speed driving. had writing on the side that said R134a. El juny de 2017, el mateix grup va decidir crear un web deDoctor Who amb el mateix objectiu. There are R134a specific valves that operate at a slightly different pressure, but not for any "old" automotive application that I'm aware of. Any suggestions, or do you need to know the hi/lo readings? What was the ambient when you took that reading?Jumpering the aux fan is a common thing here in the desert. Don't like the sound of custom parallel condensor. You'll get marginally better performance out of the change as the expansion valve is matches the refrigerant characteristics. R134a has an ozone depletion potential of 0, implying that it has a slight effect on the ozone layer. On this website we are addressing only R134a and not other suggested drop in replacements. 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. difference between r12 and r134a expansion valve Flush with a garden hose - do not use a high pressure washer - you can bend the fins flat & damage the condensor.B. It is mixed with the freon for the most part, and does accumulate in all components in small amounts. R134a vs R12 refrigerant? Catalog E-1, Thermostatic & Automatic Expansion Valves / Page 1 Table of Contents . The difference really shows up on the high side. From memory, I put in at least 8 ounces of oil, probably around 10 ounces in there. With R134a you do not rely on the site glass. Please enter a valid email address for yourself. Your old hoses of course will not fit. Thus, when the system is running, condensing the CO2 is not a problem. But as there's not a big difference, people say you can suffice with either. Yes it will work with either Refrigerant! It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. R12 systems used mineral oil, but unfortunately mineral oil doesn't dissolve in R134a. All fans must work at 100% of the OEM rating. So the steps involved are cleaning out the old oil, replacing all the O-rings, replacing the dryer, replacing the expansion valve, and converting the high and low side connectors from Schrader to quick connect valves. I used a full can of evap cleaner. With the A/c off hi and lo were both at 105psi. R134a vs R12 - What is the Differences? - Rx Mechanic The original expansion valves work very well with R134a. 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. But, if your car lacks enough condenser and you have many 100+ degree days then you may want to stick either increase air flow, add another condenser as we mentioned in The Mr. Ice Project or stick with R12. Depending on which circuit diagram fits your car (cough, no vin list exists) you have either one or two switches controlling the aux fan. 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. 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. The aux fan seems to be working fine - it switches on occassionally. Break out the new gauges and measure hi and lo at 1500rpm, and do the Merc FSM test to see how we're doing performance wise. I know this is bad, etc, and deposits on the metal can act as insulators. Read on for more information about using automotive r134a in a refrigerator and vice versa. Ensure you contact a professional mechanic to do the work for you so you dont end up incurring more costs for yourself. The adjusted tension of this spring is the determining factor in the opening and closing of the expansion valve. 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. I'm thinking of jumping the temp switch and leaving the fan on to see how it does. 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 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. Do I leave the orignal condensor in, etc?Thanks. That is a good thing. A/C R12 to R134a Conversion Success | IH8MUD Forum How about evacing 1 pound of refrig from the system, and then putting 1 lb of pure R12 back in? This is an electronic tool that sucks in air through a tube and across a sensor. We ALWAYS want to know the pressure readings! What is usually sniffed are all the connections in the system: hoses and compressor, condenser, drier, expansion valve and evaporator fittings. I am ordering new parts, and planning to convert my system to R-134a. Compressor. 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 difference between the two is about 10,000 btu/h. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. and feeds it through an expansion valve. I'll report back on the aux fan on performance next. BTW, I use a stick thermo in the vents and the laser on the condenser. This kit comes complete with Expansion valve, o-ring kit, and 1ft. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. You can use this space to go into a little more detail about your company. Thanks for the input. CR4P). 42 (at best) w/ 134A in 2000 isuzu trooper. difference between r12 and r134a expansion valve why is miles raney not on homestead rescue June 21, 2022. manila mayor candidates 2022 R134a Expansion valve different from R12? - Automotive Air Conditioning