Comparatively, larger R134a molecules should take more space, and a smaller amount might be required. We recently created this blog site to enable us to share our knowledge with other automotive mechanics and car owners. 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 . Therefore, its most suitable for both commercial and domestic environments. 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. Thanks so much Bohica - you've save me many more hours of fruitless speculation. However, R134a is better than R12. An extra half ounce? compressor, condenser, evaporator and expansion valve are specifically designed for use with R134a. However, take note that R134a refrigerants are manufactured specifically for automotive air conditioners. 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. a 50f delta across the condensor is good, but I suspect that is an idle reading. Talk about what services you provide. Mine was 61, so the system is not working as it is supposed to. 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. Where would I get some basic info on it, I know nothing about it. . Generally the system will be initially charged with approximately 80% to 85% of the original amount of R12, using R134a. 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. We consider the the various types alternative refrigerants that are illegal or not approved to be in two sectors: non-flammables and flammables. It won't be optimal, though. This works when the R12 charge specification is listed in pounds. After the initial charge the system is then tweeked : you determine the optimum amount of refrigerant to match your system by monitoring the a/c outlet vent temperature and the high side pressure as you add or remove refrigerant. However, theyre still used in older plants, systems, and the automotive industry. So to keep things simple and to avoid controversy and politics we have R134a. Depending on which circuit diagram fits your car (cough, no vin list exists) you have either one or two switches controlling the aux fan. Replacement expansion valve for R134a or R12 A/C refrigerants, with O-ring connections. had writing on the side that said R134a. This is a great space to write long text about your company and your services. I have some experience with auto a/c but not too much. 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. 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. I have the original (R12) style expansion valve in the Maverick AC system. 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. Then when it is switched off for a few minutes and then back on, the air cools again. Even with proper fan operation, missing seals & air dams can effect condensor effeciency. Trinary Pressure Switch $ 39.99. Though I have seen em run as cold as 12 deg F. If the thermo switch is malfunctioning. Theres no problem with using R134a in a home air conditioning system because it is a hydrofluorocarbon that doesnt cause environmental harm. 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. in /nfs/c05/h04/mnt/113983/domains/toragrafix.com/html/wp-content . -The amount of R-134a needed will typically be 80-90% of the R-12 charge. An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback. (On firewall where A/C lines go into cab.) Before we mentioned that you can add approximately 5-6 ounces of ester oil to the compressor. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. By after changing just about everything, he got what was termed, satisfactory cooling. Refrigerators generally utilize R22, R32, or 410A-based coolants as their cooling agent. CLUTCH CYCLING SWITCH. Hence, the effect of R12 on global warming is up to 10,000 times higher than carbon dioxide. This is the part that controls the system pressures. 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. Bookmarks: Digg; del . So you could likely put off buying those new hoses just a bit longer if you wanted. We sometimes use a relay switched from the compressor clutch to run fans. At this point it is time to make an appointment with the a/c shop. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . Its cylinders are colored white. 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!) On this website we are addressing only R134a and not other suggested drop in replacements. Thomas Jefferson, Thanks,OK, I'm starting to feel a little better about it. The newer valves and switches will work with both refrigerants. For example, if your system originally had 36 ounces of R12 then you multiply that by .80 and you have 29 ounce of R134a. Miscibility with oil: R12 can be mixed with the compressor oil no matter the operating condition. 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 The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. . There are other refrigerants: some of which may work, some of which dont work, some of which will destroy your a/c system and some of which are dangerous. R134a was selected as a replacement refrigerant for R12 because R12 contains chlorine and has a major effect to ozone layer depletion. (You must log in or sign up to reply here. 2) Frost on the Vents. The catalytic converter is an essential component of your car's emission system that helps save the environment from harmful emissions. The next piece of equipment to track down leaks is a leak sniffer. 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. The most common influences which effect the capability of R134a to perform well are the condenser, in some cases the the superheat setting of the expansion valve or the amount of R134a. Not osmosis, but you know what I mean). A final difference is that most (though not all) R-1234yf cars will have a Suction Line Heat Exchanger. 5. That is a good thing. 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). The R134a compressor has a 1/8" step in on the high side port. R134a is NOT less efficient than R12 Actually R134a is more efficient. You may be just fine on oil - it depends on what compressor you have & how much oil you put in.A T/C is short for Thermocouple. 3) A TXV optimized for 134a will be ok with R12. Failure to abide by the EPA regulations can result in expensive fines for either you or your service technician. Is there a graph? R134a refrigerant is about 10% less efficient in moving heat than R12! R134a vs R12 refrigerant? James10952001. In practice this means that the car can overheat and the aux fan will stay off! June 21, 2022 difference between r12 and r134a expansion valve . I had a 1991 BMW switched to 134a by just changing the low pressure charging valve, flushing and refilling with 134 (maybe with 10% . The original expansion valves work very well with R134a. Nice to use new gadgets! Look deep into the fins. How dumb!I will jumper the aux fan and redo the test. The cure is to use the newer R134a compressors is sealing washers that are different thickness. Jun 19, 2007. GWP is a measurement of Greenhouse Gases and their effect on Global Warming. A slow loss of cooling at city speeds is usually related to condensor capacity & airflow issues. You can use this space to go into a little more detail about your company. and he synthesized R-134a in 1936, 5 years after R-12 was . I'm going to check the condensor is way clean too. 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. Replied by Rich928 on topic R12 or R134a. If you you dont have the free time to play then you are better off to pay a technician. Can I just use an adapter and save $200? By using a black light the dye will glow in areas where oil leaks are visible. 3) A/C Compressor Always On. R12 is used in several applications like low temperature, medium temperature, and high-temperature applications. Replace the drier with a drier that has a desiccant that is R134a compatible, use new R134a o-rings. Large temperature difference between expansion valve inlet and outlet oReplace expansion valve Air . 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. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. 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. . Or is there always room for improvement, the more the merrier. 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. The larger fitting goes on the discharge port and the smaller fitting goes on the suction line or compressor inlet / suction port. The condensor airflow drops off as the fan clutch dies slowly. Safe but sorry! With tube & fin condensors in MVAC applications there is never "too much" airflow. Read on for more information about using automotive r134a in a refrigerator and vice versa. Please enter the name by which you would like to log-in and be known on this site. The condenser water inlet temperature and flow rate are controlled with the use of a . 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. How is the vent airflow?I would jumper the aux fan & check the performance. Besides, you have a greaseisel. Just leave it alone for now. The name of the oil is Polyol Ester (POE). R134a refrigerant fittings are different size. Bookmarks: Digg; del . 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. After the system has been tested out it should be checked for leaks. Can I order a valve based on the original eaton number? 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. Discussion in 'Technical' started by Jsarnold, May 25, 2012. Any ideas from the info above? Table 1 summarizes the technical characteristics of three potential R134a alternatives. There is only a temperature switch on these cars as far as I recall, and it just switches on the aux fan. Its chemical symbol is CH2FCF3. If you're getting a R134a compressor, might as well finish the job - replace the receiver/dryer, flush everything else, and convert to R134a anyhow. Questions About Becoming A Professional Member? All fans must work at 100% of the OEM rating. Is that why expansion valves are specific to R12 or R134A? Below are the major differences between R134a and R12: The chemical composition of R12 and R134a differ. If not, you just don't know unless a test is performed. Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. Paul:A 1983 240D should have a York compressor on an OEM system. This kit comes complete with Expansion valve, o-ring kit, and 1ft. Below are the major differences between R134a and R12: Chemistry The chemical composition of R12 and R134a differ. 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. You are indeed 20% out of the OEM spec for cooling. The larger line at the expansion valve is the suction line. 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. When you add fluorescent tracer dye to with the refrigerant oil it helps to track down leaks that push oil out of the system. Please enter a valid email address for yourself. To bless the system the technician should attach a R134a sticker somewhere in the engine compartment to note the car is using R134a. This drop can affect energy consumption since the plant will operate for a longer period or a larger plant will have to be installed. Its highest value is 1. Have a look in the FAQ Section, and look for "Fan clutches & testing them". I could easily be over at least 2 - 3 ounces over on the oil. I'm curiousSo there is work to do, ie performance should be able to be improved. It is made up of carbon, hydrogen, and fluorine. With R134a you do not rely on the site glass. Most importantly, the oil used in the plant must always be compatible with the refrigerant used. 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 aux fan seems to be working fine - it switches on occassionally. You do not need to replace the expansion valve in most cases. Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. american sniper longest shot; how to adjust sunsetter awning arms; pastor jeremy roberts texas. 4 Stars & Up & Up; 3 Stars & Up & Up; 2 Stars & Up . 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. 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. It does not "pool" to any degree in a large amount anywhere. But as there's not a big difference, people say you can suffice with either. If liquid refrigerant were to exit the evaporator. How about evacing 1 pound of refrig from the system, and then putting 1 lb of pure R12 back in? and recharged with mineral oil and 2.2 lbs R12. It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. What is needed? Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). However, it was found to be a very bad gas for the environment. With the A/c off hi and lo were both at 105psi. might be due to charge or different compressor and age. how to get to disney springs from boardwalk / bb dakota plaid jacket canada / difference between r12 and r134a expansion valve. If 50 degrees across the cond. This can be very very expensive. R12 and R134 are of different chemistry. 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. 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. The analysis focuses on Coefficient of Performance for . I don't think it has any air dams or seals, I'll check to make sure. Your decision could be made based on economics, environmental concerns, or both. Still, I have some simple green, so may as well give it a go. Lets take you through the advantages, disadvantages, and differences of these two refrigerants a detailed comparison including R12 vs R134a performance. What is usually sniffed are all the connections in the system: hoses and compressor, condenser, drier, expansion valve and evaporator fittings. AFAIK, there is no clutch on the engine fan on the 240D. Post photos, respond to polls and access other special features. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge. R-134a XV for R-134a use. Unfortunately, the oil only mixes with the refrigerant as a liquid. Quick View. 42 (at best) w/ 134A in 2000 isuzu trooper. Is there a source of valves by, say, eaton number? Recovery & flushing is the only way out of an oil overcharge in your vehicle.B. 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. If you have 10 ounces of oil in the system, that is contributing to the poor performance as well. Like say half a can or so recharge come springtime warm weather or something. I just got some hi/lo side gauges so I'm going to take readings, if they are needed. My turn to LOL - greasiesel! _____ 2012 E350 2006 Callaway SC560 . Superheat you can consider to be the additional amount of heat. Be sure to test @ 1500 to 2000 engine rpm, and record the ambient temp as well. 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. #4. However, R12 refrigerants are still used as fire retardants in aircraft and submarines. Compared with the cost-performance ratio, R507 is 30-40% . The common problem when converting from R12 to R134a is lack of knowledge or equipment. You will be fine with a 134a-compatible TXV running R12. As for R134a and R1234yf, theres no room for conversion. If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? R12 is highly destructive to the earths ozone layer. R134a has the chemical formula CF3CH2F and is known as tetrafluoroethane. 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 . The original rubber a/c hose lines in your car will leak out R12 through the hoses lining. Can I use the one for the R-12? Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. However, if it is taken close to a fire flame or any electrical heating element, it disintegrates into toxic products.
difference between r12 and r134a expansion valve
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