The original rubber a/c hose lines in your car will leak out R12 through the hoses lining. asia pacific stevie awards 2021. gin, amaretto cocktail. The good thing is that after you convert to R134 you can top off the system easily and cheaply. The difference between R12 and r134a is the BTU carrying capability. Thanks again. If you have the work done, be sure you find a true "A/C" shop that can make up lines. 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. Then at least I'd know really where I am on it. July 3, 2022July 3, 2022. The system has been previously converted to R-134a. Hope this helps. don't know enough about the subject to explain the choices.However, a few days ago I called the dealer to see about an OEM TEV and they said something that made me feel a little bit better; the same part number superceded every application back to the '60s, and that they couldn't do that without engineering signing off on it.Still, I would feel a lot better if I could see something written officially that compared the flow characteristics and performance of r12 and 134a TEVs are concluded that they were interchangeable in automotive applications.If someone knows of such a document I would sleep much better!Walt Edited: Mon September 12, 2005 at 8:13 PM by wamcneil. Use a drop light in the engine bay, and check the air path from the front of the car at night. A/C receiver difference between R12 and R134a? If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. What is the refrigerant property involved that has caused this? 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. 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. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. What effect would it have on performance, if any? difference between r12 and r134a expansion valve. In a comparison between R12 vs R134a vs R1234yf, R1234yf will pass as the best refrigerant. Catalog E-1, Thermostatic & Automatic Expansion Valves / Page 1 Table of Contents . The system has been previously converted to R-134a. I have some experience with auto a/c but not too much. Thomas Jefferson, Thanks,OK, I'm starting to feel a little better about it. bokoen1 hoi4 the great purge / meryl and maks dancing with the stars / difference between r12 and r134a expansion valve. However, it was found to be a very bad gas for the environment. 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. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores. Electric fans do wear out. Accessories Pumps, Cooling Towers, Evap Condensers, etc, Components Valves, Motors, Condensers, Evaporators, etc, Duct Systems Design, Installation & Practice, Piping Systems Design, Installation & Practice, Control System Design, Installation & Practice, Pro's Forum: National Electrical Code (NEC), Pro's Forum: Calculations & Electrical Theory, Pro's Forum: Electrical Business & Marketing. On the other hand, R12 has a global warming potential of 10,910. You can also check the Aux fan in your case. Differences between R-12 and R-134a systems: 1. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. By using a black light the dye will glow in areas where oil leaks are visible. In large application systems, the vapor density of this refrigerant is usually high. R134a and R12 are among the most popular types of refrigerants. Lets take you through the advantages, disadvantages, and differences of these two refrigerants a detailed comparison including R12 vs R134a performance. However, it was found to be a very bad gas for the environment. A lower GWP alternative to R-134a had to be found and thus we have the new 1234yf. It won't be optimal, though.On some/many valves, you can adjust them, but that might make matters worse unless you really know what you're doing (which I don't!).RegardsGeorge. The safe high side pressures are determined with a PT (pressures and temperatures) chart. Any suggestions, or do you need to know the hi/lo readings? Maybe a jerky locker.I cleaned the condensor with the off the shelf ac cleaner stuff from Home Depot that I used on my home evaporator. R134a refrigerant fittings are different size. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. 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. Look deep into the fins. 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. Consider using the newer valve, even with 134a stamped on the valve. Sense ells no existirem. Since 2010, all home AC systems manufactured use a refrigerant like R134a that has zero ozone depletion potential (ODP). Different correction factors are applied to other refrigerants. and recharged with mineral oil and 2.2 lbs R12. SO here's my question. B. But I don't want to waste your time. For example, if your system originally had 36 ounces of R12 then you multiply that by .80 and you have 29 ounce of R134a. Jun 19, 2007. The R134a compressor has a 1/8" step in on the high side port. . 5. Debug the condensor (I am a computer nerd after all!)3. Use strips of foam to couple the two heat exchangers if necessary.B. 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. I could easily be over at least 2 - 3 ounces over on the oil. 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 . compressor, condenser, evaporator and expansion valve are specifically designed for use with R134a. Mark Baker R-401b is the mixture by weight of 61% R22, 11% R-152a and 28% of R-124. There is only a temperature switch on these cars as far as I recall, and it just switches on the aux fan. If the charge is low the compressor will cycle on/off in the max AC position. Even with proper fan operation, missing seals & air dams can effect condensor effeciency. 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. I used a full can of evap cleaner. Inasmuch as R134a has a global warming potential thats over 1000 times more threatening than carbon dioxide, its better than R12. Is there a difference between a R134a expansion valve and an R12 TXV? Also, R134a cylinders are light-blue in color. Spray it deep, and let it sit for a few minutes. The oil used in R12 systems is not compatible with R134a refrigerant. If not, you just don't know unless a test is performed. Using R134a requires that Polyolester (POE) lubricant must be used in the compressor. Then again, there are two different expansion valves. Heres R12 vs. R134a pressure chart. We've updated our forums!Click here to visit the new forum, Year: 1983Make: MercedesModel: 240DEngine Size: 2.4Refrigerant Type: R12Ambient Temp: 90Pressure Low: 35Pressure High: ?Country of Origin: United States, Hi, this is my first post, so please take it easy on the noob. 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. 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. 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 R134a compressor has a 1/8" step in on the high side port. I know this is bad, etc, and deposits on the metal can act as insulators. 4.R404A R134a increased mass transfer resistance to reduce the transmission chamber heat coefficient, while R507 heat transfer coefficient is higher than R404A. Even if the system leaks, repairing the leaks and recharging it with R-12 is usually the best repair alternative. How about evacing 1 pound of refrig from the system, and then putting 1 lb of pure R12 back in? R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. R134a requires the use of synthetic oil! In sum, R12 has done more bad than good. The only difference I can imagine would be the recharge connection. gital control scheme. The problem with not being an expert is that you don't know what is important and what's not. The original CFC expansion valve used for R12 needs to be replaced with an HFC one for 134a to feed the evaporator correctly. The cure is to use the newer R134a compressors is sealing washers that are different thickness. -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a, Hi pdrayton- If you can remember the oil capacity that you found in all your research and post that, then bohica and others can have a better idea if you have too much; see if you can find that info! 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. The larger fitting goes on the discharge port and the smaller fitting goes on the suction line or compressor inlet / suction port. Generally the system will be initially charged with approximately 80% to 85% of the original amount of R12, using R134a. 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. The difference really shows up on the high side. With new R12 no longer being manufactured, the market price soared to $100/pound. Carefully study the chart and compare the following: To a large extent, the choice is up to you. The Main change in the system is the expansion valve. There is a lot of differences between the R12 and the R134a fittings, you can't mistake them. ThanksPaul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. Thus, when the system is running, condensing the CO2 is not a problem. R12 is highly destructive to the earths ozone layer. As per their results . If 50 degrees across the cond. Bohica, I appreciate your help with this. So, instead of using R12, other better options include R401b, R134a, R401a, etc. It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. Statisicaly your friend was lucky. 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 Use a strong surfactant like Simple Green or Zep Citrus, and soak the fins on the condensor. The next piece of equipment to track down leaks is a leak sniffer. The common problem when converting from R12 to R134a is lack of knowledge or equipment. R134a and R12 are both refrigerants used in vehicle air conditioning systems. A discussion of the relationship between valve capacities and superheat set-tings can be found in Bulletin 10-9. Replace the drier with a drier that has a desiccant that is R134a compatible, use new R134a o-rings. The aux fan didn't switch on though and I didn't check the high side temperature. Plus, not releasing the chemical into the air is morally justifiable. Recomanem consultar les pgines web de Xarxa Catal per veure tota la nostra oferta. Then I'll put the ball valve in on the coolant and test it and see what we have. . We suggest dumping the old refrigerant oil in a clean container and inspect the oil for sludge or waxing (old oil that has gelled) and contamination (metal particles). Nick, I hear you - there maybe nothing to do here. We say generally because the vehicle manufacturer may have a formula already worked out for the R134a conversion process. This means that it has a high potential of causing depletion to the ozone layer. I would not do a 134a conversion without a PF condensor. Just because the radiator does not boil people assume that the cooling system is ok. Besides R134a there are some other refrigerants that are approved to replace R12 and there is a long list of refrigerants that are not approved. R12 is otherwise called dichlorodifluoromethane is a colorless gas (chlorofluorocarbon halomethane (CPC) that is used as an aerosol spray propellant and a refrigerant, and is soluble in organic solvents. Some say that a chemical reaction can harm the A/C very badly as R134a reacts with mineral oil in some way. Theres no problem with using R134a in a home air conditioning system because it is a hydrofluorocarbon that doesnt cause environmental harm. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. 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. If the system was upgraded by a professional it should have an upgrade sticker. The butylcellusolve or the citrus solvent will dissolve the carcass in a few minutes. Does it matter - assuming both are new & uncontaminated? Unfortunately, the oil only mixes with the refrigerant as a liquid. Large temperature difference between expansion valve inlet and outlet oReplace expansion valve Air . 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. It's helluva humid and hot here in north florida, and I drive around all day for my job. The money you will save by will pay for the R12. and he synthesized R-134a in 1936, 5 years after R-12 was . An extra half ounce? 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 . Some 1993 and older R12 systems aren't as 'compatible' as you'd think to switch over. Flushed, vacuumed etc. Instead, top off R12 with R134a refrigerant. difference between r12 and r134a expansion valve. Make sure to wear safety gloves, goggles, and shoes when theres a possibility of exposure to the chemical (R134a). The name of the oil is Polyol Ester (POE). 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. Generally this works well for the whole system. Below are the major differences between R134a and R12: Chemistry The chemical composition of R12 and R134a differ. difference between r12 and r134a expansion valve. 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. 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!) Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. Here are the basics for converting a system that does not have a charge of R12, its empty. James10952001. I remember I had the wrong seals and it leaked some oil, so I put some more in.Bohica - I tested the pressures. I'm curiousSo there is work to do, ie performance should be able to be improved. It's not just the poor performance - the cooling just stops working after a while. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? Trinary Pressure Switch $ 39.99. -The amount of R-134a needed will typically be 80-90% of the R-12 charge. He used thermostatic expansion valve and Capillary tube for analysis with R12. You can spend long evenings reading about the differences between the two refrigerants. El juny de 2017, el mateix grup va decidir crear un web deDoctor Who amb el mateix objectiu. They might say for instance, add 3-4 oz of oil to the compressor, 1 oz of oil for when you replace a drier, 2 oz oil for the evaporator and so on. absorb by the evaporator to insure all liquid refrigerant entering the evaporator. GWP is a measurement of Greenhouse Gases and their effect on Global Warming. The compressors used by refrigeration plants to compress gas require oil to help lubricate its moving parts. Though - the valve for a 1991 says R12 on it, and for a 1994, it says R-134a. The analysis focuses on Coefficient of Performance for . It does not "pool" to any degree in a large amount anywhere. I'll report back on the aux fan on performance next. Swapping the components isnt a herculean task, but recharging the AC is a challenge. 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. However, if it is taken close to a fire flame or any electrical heating element, it disintegrates into toxic products. 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. The substitute that we used for R-12 was the new HFC called R-134a. This works when the R12 charge specification is listed in pounds. R404a for freezing of product. 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. 3) A TXV optimized for 134a will be ok with R12. Still, I have some simple green, so may as well give it a go. R134a is the most widely accepted alternative automotive refrigerant used to replace R12. It is possible I have 10 ounces (250 ml) in the system. 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. difference between r12 and r134a expansion valve. is good, then I should be looking elsewhere? At 2000rpm, windows open, highest fan, hi pressure stabilized at 225 psi, low 25psi.Ambient 81F, vent 61F. The oil used in R12 and R134a are different and not compatible. Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. -------------------------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. Nice to use new gadgets! 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. I am ordering new parts, and planning to convert my system to R-134a. a 50f delta across the condensor is good, but I suspect that is an idle reading. 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. If liquid refrigerant were to exit the evaporator. 3 ounces? 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. Blows pretty hard on full. 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. Is there a difference between a R134a expansion valve and an R12 TXV? Looks like a couple of things happening here1) 80's vintage Eurocars were not "meat lockers". #4. Is that why expansion valves are specific to R12 or R134A? These efforts to balance the system can not be realized if there are problems within the a/c system, such as: poor performing compressor, dirty condenser or poor air flow through the condenser, malfunctioning expansion valve, water or air in the system, improperly operating fresh air or heat input in the climate-air mixing system. R134a is NOT less efficient than R12 Actually R134a is more efficient. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. Is there a difference in the expansion valve for R12 as opposed to R-134a? Its among the greenhouse gases and will keep adding the current problem of heat not leaving the earths atmosphere. Until 1995, most cars with air conditioning used R-12 Freon refrigerant which has shown to have an environmental impact. of coiled cap tube on VCR system with R134a. VerticalScope Inc. All Rights Reserved. B. R134a was selected as a replacement refrigerant for R12 because R12 contains chlorine and has a major effect to ozone layer depletion. CLUTCH CYCLING SWITCH. R12 was once used in many air conditioning units as a refrigerant or cooling agent. R12 and R134 are of different chemistry. This is due to many facts: R134a refrigerant is about 10% less efficient in moving heat than R12! Not osmosis, but you know what I mean). Edited: Tue July 17, 2007 at 3:25 AM by bohica2xo, I believe there is only one switch - the refrigerant switch. But as there's not a big difference, people say you can suffice with either. How an A/C Expansion Valve Works. R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. In more serious, it could result in cardiac irregularities or death. It's actually a reaction with chlorine in the mineral oil that may have been absorbed and leftover from the old R-12. Pray I can let some oil out of the compressor without losing my precious R12. Make sure visiually that no large gaps exist that would allow the air to bypass the condensor on the way to the radiator.B. How is the vent airflow?I would jumper the aux fan & check the performance. A Lot of the fins are bent, especially at the top. It is mixed with the freon for the most part, and does accumulate in all components in small amounts. Where would I get some basic info on it, I know nothing about it. The exact amount will vary with each car. It slowly gets warmer and warmer in the car, even at highway speeds. I put one in my old daily driver '79 Chevy tank (r-12), and it really made a difference. 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 Moreso, it had been banned. 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. 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. This would become an expensive investment for a repair or service station to have unique dedicated equipment for every type of alternative refrigerant. What is a good differential? We consider the the various types alternative refrigerants that are illegal or not approved to be in two sectors: non-flammables and flammables. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. By noting the ambient temperature you can look up what the preferred high side pressure should be. Don't like the sound of custom parallel condensor. 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. R134a refrigerant is lighter than R12. . The approval is very legal one, governed by the U.S. EPA. Concentration level: The R134a vapor dilutes the oxygen concentration in the air to a low level, thereby causing harm. 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. Ask Our Pros-Owner Assistance - NO DIY advice will be given. R12 is used in several applications like low temperature, medium temperature, and high-temperature applications. They examined the two configurations of capillary tubes i.e. 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? Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). R12 and R22 are both now banned by the EPA in the United States. 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. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. 5. We sometimes use a relay switched from the compressor clutch to run fans.