Kommentare . Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? Jun 19, 2007. Further production of R12 was banned in some developed countries by the Montreal Protocol because of its harsh effect on the ozone layer. Recharge the compressor with a/c ester oil and a tracer dye. So I probably put the highest suggested amount in to be safe. Generally, the new amount is 75-85% of the quantity advised by the manufacturer. There is NO reason to retrofit a vehicle to R-134a as long as the R-12 system is cooling properly and contains a normal charge of refrigerant. This implies that the discharge pressure of the compressor should be moderate so it can produce the refrigerants condensation in the condenser at the atmospheric temperature. Ensure you contact a professional mechanic to do the work for you so you dont end up incurring more costs for yourself. #19. PaulJerky King -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. You may need to adjust the valve in a bit to get desired superheat. R12 was once used in many air conditioning units as a refrigerant or cooling agent. R1234yf. The compressors used by refrigeration plants to compress gas require oil to help lubricate its moving parts. The aux fan seems to be working fine - it switches on occassionally. It slowly gets warmer and warmer in the car, even at highway speeds. Thanks for the input. This leads me to labor over every small decision. Usually, mechanics charge around $200 for conversion. Instead, top off R12 with R134a refrigerant. Different correction factors are applied to other refrigerants. Thread starter goldNSX; Start date 1 August 2009; Tagged . 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. This is an electronic tool that sucks in air through a tube and across a sensor. That would be the "black death" syndrome. Since then, the industry standard has been R134a, which is an efficient replacement. R12, on the other hand, is called chlorofluorocarbon (CFC). R134a refrigerant is about 10% less efficient in moving heat than R12! Your decision could be made based on economics, environmental concerns, or both. Once you have replaced the OEM condensor with a PF unit, you will need to make custom hoses to mate with your OEM system. I don't want to be chasing ghosts. 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. The cable is adjustable at the valve arm. Safety: R134a is safe to use as its non-flammable and cant explode. I'm doing one thing at a time so I know what the cause was. Vent temperatures slowly go down to around 50F with hi speed driving. R134a has an ozone depletion potential of 0, implying that it has a slight effect on the ozone layer. We've updated our forums!Click here to visit the new forum, Year: 1991Make: Jaguar Model: XJ6Engine Size: 4.0. As per their results . The pressure at low temperatures is nearly the same between 12 and 134a. This is a great space to write long text about your company and your services. To ensure the right charge, you must fill the new system with between 75 and 85% of the factory-set capacity for optimal cooling. Gnats & mosquitos will clog deep. . A/C receiver difference between R12 and R134a? Interestingly, theres one oil type that works perfectly with both types of refrigerants. There is only a temperature switch on these cars as far as I recall, and it just switches on the aux fan. and feeds it through an expansion valve. 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. Please enter a password for your user account. I don't know where it is getting the switch off command, or why the vent temp drops steadily. In practice this means that the car can overheat and the aux fan will stay off! ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. 2) Frost on the Vents. With the knowledge of the differences, youll be able to draw a comparison between R12 vs R134a efficiency. There are three different refrigerants officially sanctioned by the EPA for automotive usage: r-12, r-. If the system was upgraded by a professional it should have an upgrade sticker. 5. 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. The original CFC expansion valve used for R12 needs to be replaced with an HFC one for 134a to feed the evaporator correctly. A/C Expansion Valve Replacement Cost. You do not need to replace every o-ring in the system, but if you happen to open a connection that has an o-ring you should replace the old o-ring with one that is compatible with R134a and lubricate the o-ring with ac oil. I had to vaccum the system for 2 hours and recharge 4 oz of PAG oil plus 36 oz of 134A freon (3 cans). I found that in the..Maxposition on the control it will have the compressor running all the time. Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. However, if it is taken close to a fire flame or any electrical heating element, it disintegrates into toxic products. #4. 34 in 70 series w/ R12 in 100+ Tucson, AZ summer heat w/ hd-t, w/ 13B-T is was unbearable about 31 at vent w/ R12. I bought a relay to put on it connected to the compressor clutch. Rules governing changing from the former to the latter differ between countries. So that indicates it is cooling well there doesn't it? 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. 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. In addition, R134a refrigerants are not only used in auto air conditioners, they can be used in freezers, aerosol cans, and refrigerators. R12 Expansion Valve = 201 830 06 84 R134A Expansion Valve = 201 830 04 84 Is there a difference after all? This kit comes complete with Expansion valve, o-ring kit, and 1ft. look at the difference! . Use a drop light in the engine bay, and check the air path from the front of the car at night. Sense ells no existirem. Then at least I'd know really where I am on it. For those of you who are considering what the cost is for R12 you can think of it this way: Dont go out to dinner this weekend. 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. I've straightened the fans I can and sprayed simple green on it, let it soak then hosed it down well. Heres some important advice Whenever you notice your R12 refrigerant is leaking, turn off all flames and open the doors so it can escape to the open atmosphere. The system has been previously converted to R-134a. It would make a big difference at idle ,in traffic!! 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. The major reason for the replacement of R12 with R134a was to curb future greenhouse effects. It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. The difference really shows up on the high side. A Lot of the fins are bent, especially at the top. According to the thermodynamic characteristics, it is close to the R12 freon, however, it is 10-15% worse in terms of cooling capacity and is more fluid. The safe high side pressures are determined with a PT (pressures and temperatures) chart. Swapping the components isnt a herculean task, but recharging the AC is a challenge. 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. R134a and R12 are both refrigerants used in vehicle air conditioning systems. Why wait for 200f on the engine coolant to start the fan? Below are the major differences between R134a and R12: Chemistry The chemical composition of R12 and R134a differ. "Howdy, Folks!" These cheap kits usually have a few cans of R134a (either 12 ounce or 16 ounce), maybe an extra can of refrigerant oil, a few generic R134a charge port adapters and maybe some o-rings. What effect would it have on performance, if any? It will work and there will be very little, in any difference in performance.As Chick stated, the difference is only the gas used in the sensor tube. Is there a difference between a R134a expansion valve and an R12 TXV? Make sure to get the R12 EXP valve if that is the way you go. Look at where the lines will end up. The reason is that the vehicles, for instance, manufactured currently configure the engine for R1234yf refrigerant, making no provision for replacement. 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. Generally the system will be initially charged with approximately 80% to 85% of the original amount of R12, using R134a. It cycles on off in med (or low for that matter)Gotta tell ya. 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. For instance you can evacuate FRIGC FR-12 into a refrigerant recovery bottle that has R134a in it or visa versa. One thing at a time here, and slowly, the knee is not up to jumping around like I used to at the moment. -------------------------"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest." 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. Automotive Replacement Expansion Valves & Parts; Industrial & Scientific; Customer Reviews. Warning: "continue" targeting switch is equivalent to "break".Did you mean to use "continue 2"? Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. Most vehicles manufactured before 1993 have the R12 A/C system. An extra half ounce? Related products. 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. R134a is NOT less efficient than R12 Actually R134a is more efficient. With R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. I'm curiousSo there is work to do, ie performance should be able to be improved. . Like say half a can or so recharge come springtime warm weather or something. If you have a perfectly operating system using R12 you do not have to drop what you are doing and convert to R134a. When the temperature is reduced to-7C or below, the plants ability to cool the airdrops significantly. Ask Our Pros-Owner Assistance - NO DIY advice will be given. I recommend replacing the expansion valve when you do the swap. Also called the orifice tube. Generally you follow the refrigerant flow moving from connection to connection, component to component, and you sniff the a/c vents to check for evaporator leaks as well. Edited: Tue July 17, 2007 at 3:25 AM by bohica2xo, I believe there is only one switch - the refrigerant switch. R134a refrigerant is lighter than R12. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . Then when it is switched off for a few minutes and then back on, the air cools again. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. On this website we are addressing only R134a and not other suggested drop in replacements. Also, it can be used with all types of compressors. Low refrigerating effect per pound: In comparison to other refrigerants, the refrigerating effect of R12 per pound is low. The chemical composition of R12 and R134a differ. What is a good differential? So you could likely put off buying those new hoses just a bit longer if you wanted. 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. absorb by the evaporator to insure all liquid refrigerant entering the evaporator. is good, then I should be looking elsewhere? Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. This is 11F off the FSM performance graph - vent should be around 50F. I'll put the relay on for that. "Jerky Locker" LMAO I am using that one in the future!Florida = BUGS! Just had knee surgery yesterday, so I"M not exactly hopping around too well. CONCLUSIONS The differences in the theoretical C.O.P.H calculated for R12 and R134a are consistent with values quoted in the literature. 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. Operating Pressure/Temperature Differences The pressure/temperature curves for R-1234yf and R-134a are very similar. The oil is spread all over your system when it is at rest. Lets take you through the advantages, disadvantages, and differences of these two refrigerants a detailed comparison including R12 vs R134a performance. I'm having the same concern. Expansion Valve. Could that be screwing up the systems performance?Anyway, when I installed the system, the new TXV (is that short for expansion valve?) Still, I have some simple green, so may as well give it a go. Very nice! You can use the R134a retrofit capacity chart for this purpose. = R134a Charge Level. Your old hoses of course will not fit. Very interesting! 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. of refrigerant insulation tape. It has already been clearly stated that R12 is a chemical that damages the earths ozone layer and shouldnt be released into the environment no matter the circumstance. 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. About four or five years ago, I guy with an MB came here with the same problem, that tread was over six pages long. Its chemical symbol is CCl2F2. Any suggestions, or do you need to know the hi/lo readings? However, it was found to be a very bad gas for the environment. Skin contact: If the R134a (liquid) comes in contact with your skin, it could cause a burn. Reattach the hose lines using new R134a compatible o-rings, lightly lubricate with compressor oil. R134a requires a different oil. Should I do the test again with the the aux fan jumpered? The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. It is usually sold under the brand name, Freon 12. Are you sure you have an R4? Paul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. Then again, there are two different expansion valves. 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. Catalog E-1, Thermostatic & Automatic Expansion Valves / Page 1 Table of Contents . 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. Hope this helps. It is perhaps possible to locate a unit with a company that purchases close out or distressed merchandise. A final difference is that most (though not all) R-1234yf cars will have a Suction Line Heat Exchanger. The problem with not being an expert is that you don't know what is important and what's not. First, differences in physical properties: 1, insoluble R12 compressor oil is used (to reduce the lubricant) 2, dissolved sealing materials are used (resulting in refrigerant leakage) 3, easy to damp (so easy to internal . It is possible I have 10 ounces (250 ml) in the system. This means that it has a high potential of causing depletion to the ozone layer. This would become an expensive investment for a repair or service station to have unique dedicated equipment for every type of alternative refrigerant. Therefore, the higher the factor of the chemical (compound), the greater its effect on global warming. Flushed, vacuumed etc. With tube & fin condensors in MVAC applications there is never "too much" airflow. For instance at 25 F the pressure of R-12 is 24.6 PSI and the pressure of R-134a is 22.1 PSI. and he synthesized R-134a in 1936, 5 years after R-12 was . 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. -------------------------"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest." Hence, the effect of R12 on global warming is up to 10,000 times higher than carbon dioxide. The flammables have hydrocarbons. It is made up of carbon, hydrogen, and fluorine. They examined the two configurations of capillary tubes i.e. R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. Remember, being aluminum, they lower the temps better, and do not pass off as much heat to the radiator, which then makes it's job easier and lowers underhood temps (besides lowering vent temps inside the car). 4) Repeat step 2, making sure it will fit. What is needed? Electric fans do wear out. If you find any of these conditions you will want to liquid flush (with dedicated AC flush solution) all the lines, condensers, evaporator (remove the expansion valve) before you proceed further. 2001-2023 Griffiths Technical Inc. All Rights Reserved. If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? Als nostres webs oferimOne Piece,Doctor Who,Torchwood, El Detectiu ConaniSlam Dunkdoblats en catal. Some 1993 and older R12 systems aren't as 'compatible' as you'd think to switch over. R134a is otherwise called 1,1,1,2 Tetrafluoroethane, Florasol 134a, Freon 134a, Norflurane (INN) or HFC 134a. The current expansion valve is FF - 1/4 - C. Is it neccesary to replace this valve? If the charge is low the compressor will cycle on/off in the max AC position. For R12, its mineral oil. Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. 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. Replied by Rich928 on topic R12 or R134a. Also, they are mostly used in refrigeration and automotive air conditioning systems. Only show this user. Talk about what services you provide. By noting the ambient temperature you can look up what the preferred high side pressure should be. difference between r12 and r134a expansion valve . You'll want the expansion valve matched to whatever refrigerant you're using. 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 cleaned the evap as best I could, if that is what you are getting at. 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. 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. Yes it will work with either Refrigerant! Statisicaly your friend was lucky. In sum, R12 has done more bad than good. It is made up of carbon, hydrogen, and fluorine. I don't think it has any air dams or seals, I'll check to make sure. It didn't seem too dirty though - I don't think it is the problem, but I could be wrong. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. Can I just use an adapter and save $200? Its chemical symbol is CH2FCF3. I think so. 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. Some say that a chemical reaction can harm the A/C very badly as R134a reacts with mineral oil in some way. It's actually a reaction with chlorine in the mineral oil that may have been absorbed and leftover from the old R-12. The oil used in R12 systems is not compatible with R134a refrigerant. 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. 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 compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. 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. 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. 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. But as there's not a big difference, people say you can suffice with either. Is that reasonable?Vent airflow is good, I think. The analysis focuses on Coefficient of Performance for . It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. 42 (at best) w/ 134A in 2000 isuzu trooper. -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. R1234yf is more environmentally friendly and has a global warming potential of 4. ing the expansion valve, a maximum opening superheat of 7F, and a standard factory air test superheat setting. However, theyre still used in older plants, systems, and the automotive industry. 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. . I think the way to go here is1. After the system has been tested out it should be checked for leaks. An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback. The condensor airflow drops off as the fan clutch dies slowly. Trinary Pressure Switch $ 39.99. However, it was found to be a very bad gas for the environment. 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. Rxmechanic.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for website owners to earn advertising fees by advertising and linking to Amazon.com. However, the supply houses don't indicate a difference. Concentration level: The R134a vapor dilutes the oxygen concentration in the air to a low level, thereby causing harm. Inhalation of vapor: Inhaling a large amount of R134a vapor can lead to drowsiness, temporary nervous system depression, and lethargy. 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). Comparatively, larger R134a molecules should take more space, and a smaller amount might be required. It won't be optimal, though. Is there a graph? 05-25-2017 02:14 AM. And, unfortunately a small high side pressure gauge on a short hose. Some cars have both an engine coolant temp switch & a refrigerant temp switch, others only the refrigerant switch. Best for varieties of operating conditions: Its boiling point is -21.6 Celsius. R134a. The cost of recharging the air conditioner is between $150 to $500. The original expansion valves work very well with R134a. Blows pretty hard on full. 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. El juny de 2017, el mateix grup va decidir crear un web deDoctor Who amb el mateix objectiu. A. Pressure/temperature plot of R134a vs. R12 is shown in figure 1. VerticalScope Inc. All Rights Reserved. Failure to abide by the EPA regulations can result in expensive fines for either you or your service technician. 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. If you have 10 ounces of oil in the system, that is contributing to the poor performance as well. Lasers don't do well on vent temps, a stick thermometer is better in that application. Some compressor manufacturers or OEMs suggest PAG type oil for R134a. hardly noticable. -------------------------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 symbol implies that R12 is a composite of carbon, chlorine, and fluorine. Is that why expansion valves are specific to R12 or R134A? Generally this works well for the whole system. Please enter the name by which you would like to log-in and be known on this site. Until 1995, most cars with air conditioning used R-12 Freon refrigerant which has shown to have an environmental impact. 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.
Jason Cermak Brother, Articles D
Jason Cermak Brother, Articles D