Its chemical symbol is CCl2F2. Like say half a can or so recharge come springtime warm weather or something. In 1994 they switched from R-12 to R-134a. R134a refrigerant fittings are different size. Related products. However, R12 refrigerants are still used as fire retardants in aircraft and submarines. Are r12 and r134 fittings different? The cure is to use the newer R134a compressors is sealing washers that are different thickness. Statisicaly your friend was lucky. R-134a is widely believed to be the most acceptable R12 substitute. The system has been previously converted to R-134a. A discussion of the relationship between valve capacities and superheat set-tings can be found in Bulletin 10-9. You may need to adjust the valve in a bit to get desired superheat. I'm thinking I might have put too much oil in the system - everywhere i read had a different amount - the manufacturer of the compressor, the MB factory service manual, online forums. The difference between R12 and r134a is the BTU carrying capability. Not going to mess up your 'do, but you can feel it. The value of carbon dioxide is 1. However, the supply houses don't indicate a difference. The AC usually does not work at all. Inhalation of vapor: Inhaling a large amount of R134a vapor can lead to drowsiness, temporary nervous system depression, and lethargy. This would become an expensive investment for a repair or service station to have unique dedicated equipment for every type of alternative refrigerant. Just had knee surgery yesterday, so I"M not exactly hopping around too 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. Is it exponential, squared? A comparison between R12 vs. R134a temperature will show that R12 has a higher temperature than R134a. sparkee said: Thanks for the Service Bulletin. All fans must work at 100% of the OEM rating. The compressors used by refrigeration plants to compress gas require oil to help lubricate its moving parts. Besides, you have a greaseisel. If you have a York, and it is equipped with service valves, you can check & adjust the oil level without discharging the system. How is 1234yf different from . we convert older systems where i work all the time and they work fine. I don't have the FSM matrix handy for that 123.123, but a 123.133 shows a test rpm of 2,000 - and vent temps between 54f & 66f at 91f to 95f ambient. Low refrigerating effect per pound: In comparison to other refrigerants, the refrigerating effect of R12 per pound is low. 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. The primary function of the design engineer is to make things difficult for the fabricator and impossible for the serviceman. Not osmosis, but you know what I mean). Pound for pound R134a is a more efficient refrigerant than R12, however it runs at higher pressures in some aspects and therefore requires more effective condensing. They examined the two configurations of capillary tubes i.e. 1) Warm Air From Vents. As illustrated in the chart below, the curves below run together nearly throughout the curve, only slightly breaking paths at around 250 psig/150 degrees and above Flammability/Safety R-1234yf has been designated as MILDLY flammable. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. difference between r12 and r134a expansion valve. Why wait for 200f on the engine coolant to start the fan? Thus, when the system is running, condensing the CO2 is not a problem. That is for the compressor, drier, expansion valve and condenser. Trinary Pressure Switch $ 39.99. 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. You can spend long evenings reading about the differences between the two refrigerants. Replace the drier with a drier that has a desiccant that is R134a compatible, use new R134a o-rings. It runs between the condenser outlet, receiver/drier unit and expansion valve at the firewall. R134a has an ozone depletion potential of 0, implying that it has a slight effect on the ozone layer. Its highest value is 1. 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. Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. 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. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. 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. 1.5 ounces - hmmm. R12 is used in several applications like low temperature, medium temperature, and high-temperature applications. The original expansion valves work very well with R134a. An extra half ounce? Generally, the new amount is 75-85% of the quantity advised by the manufacturer. video clubhouse baseball; nick fairley draft profile; ben davis work pants -------------------------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! bokoen1 hoi4 the great purge / meryl and maks dancing with the stars / difference between r12 and r134a expansion valve. Table 1 summarizes the technical characteristics of three potential R134a alternatives. How an A/C Expansion Valve Works. "Jerky Locker" LMAO I am using that one in the future!Florida = BUGS! I used a full can of evap cleaner. Just leave it alone for now. Ask Our Pros-Owner Assistance - NO DIY advice will be given. "Howdy, Folks!" From memory, I put in at least 8 ounces of oil, probably around 10 ounces in there. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. And, unfortunately a small high side pressure gauge on a short hose. This refers to BTU's (heat) moved per pound of refrigerant moved. In a comparison between R12 vs R134a vs R1234yf, R1234yf will pass as the best refrigerant. R134a. Once you have replaced the OEM condensor with a PF unit, you will need to make custom hoses to mate with your OEM system. We say generally because the vehicle manufacturer may have a formula already worked out for the R134a conversion process. AFAIK, there is no clutch on the engine fan on the 240D. 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. hardly noticable. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. I think the way to go here is1. 5. 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. When the sensor detects the refrigerant leak the sniffers lights glow and the sniffer makes a noise. What is a T/C?4. Components Coils, Heaters, Motors, etc. It was later found that R-134a had a very high Global Warming Potential, or GWP, number. Jun 19, 2007. Whenever its exposed to the environment, it changes to a gas. Depending on which circuit diagram fits your car (cough, no vin list exists) you have either one or two switches controlling the aux fan. . Superheat you can consider to be the additional amount of heat. If your compressor requires replacement or its seals and o-rings need to be replaced due to leakage, it would be wise at this time to either obtain a compressor that has o-rings and seals that are compatible with R134a or have your unit re-manufactured with compatible components. The first vehicle that used the R1234yf refrigerant was the 2013 Cadillac XTS. 30 deg is pretty coldSystems generally run between 40 and 43 deg. 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. $21 . R1234yf. It is a haloalkane and hydrofluorocarbon (HFC) refrigerant that has thermodynamic properties, potential global warming for one hundred years, and insignificant ozone depletion. Shorting the plug for the refrigerant switch should run the fan when the compressor is on. A slow loss of cooling at city speeds is usually related to condensor capacity & airflow issues. The original CFC expansion valve used for R12 needs to be replaced with an HFC one for 134a to feed the evaporator correctly. Even though their common major function is to cool the system, they have many differences. You will be fine with a 134a-compatible TXV running R12. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. For example, if your system originally had 36 ounces of R12 then you multiply that by .80 and you have 29 ounce of R134a. Though - the valve for a 1991 says R12 on it, and for a 1994, it says R-134a. Then when it is switched off for a few minutes and then back on, the air cools again. The larger line at the expansion valve is the suction line. The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. 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 . 5. Pray I can let some oil out of the compressor without losing my precious R12. But, what is considered a good temperature differential across the condensor? #4. You can use the R134a retrofit capacity chart for this purpose. Blows pretty hard on full. 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 . There is a lot of differences between the R12 and the R134a fittings, you can't mistake them. Use strips of foam to couple the two heat exchangers if necessary.B. Paul:It is never a waste of my time to chat with someone that understands the problem, and wants to fix it. In no particular order, here's what I've found out regarding answering the questions posed so far:Fonebone - It is definitely an R4 compressor (they left the c off the front and the p off the end, i.e. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . Recharge the compressor with a/c ester oil and a tracer dye. It is mixed with the freon for the most part, and does accumulate in all components in small amounts. This is 11F off the FSM performance graph - vent should be around 50F. R134a requires the use of synthetic oil! Compatible with multiple applications: The major reason for the introduction of R134a was to replace R12, so it functions perfectly in the same range of applications like rotary, screw, and centrifugal compressors for air conditioning and refrigeration. R12 and R134 are of different chemistry. Yes it will work with either Refrigerant! Any suggestions, or do you need to know the hi/lo readings? Please enter a password for your user account. Mark Baker R-401b is the mixture by weight of 61% R22, 11% R-152a and 28% of R-124. -------------------------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. I don't believe it is but I had a service guy tell me it needs to be done. Thanks again. The crossover point is approximately at 64F. Disconnect the two hose lines to the compressor, protect the ends from getting dirty. It's not just the poor performance - the cooling just stops working after a while. Edited: Sat July 14, 2007 at 10:22 PM by fonebone. I found that in the..Maxposition on the control it will have the compressor running all the time. The mechanical fan & clutch should be checked as well. It may take a couple of tries to get things really clean.The laser is usually close on clean surfaces, but I prefer a T/C. The reason is that the vehicles, for instance, manufactured currently configure the engine for R1234yf refrigerant, making no provision for replacement. So you could likely put off buying those new hoses just a bit longer if you wanted. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. It slowly gets warmer and warmer in the car, even at highway speeds. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. 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. #19. 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. To bless the system the technician should attach a R134a sticker somewhere in the engine compartment to note the car is using R134a. 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. difference between r12 and r134a expansion valvewarning signs for a deteriorating patient with covid 19 infection 2022.07.03 18:36 18:36 As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. 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. I don't want to be chasing ghosts. The ratings for evaporator temperatures 40F, 20F, -10F, -40F in the capacity tables are in accordance with ANSI/ARI = R134a Charge Level R12 Expansion Valve = 201 830 06 84 R134A Expansion Valve = 201 830 04 84 Is there a difference after all? The R134a compressor has a 1/8" step in on the high side port. 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 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. For instance you can evacuate FRIGC FR-12 into a refrigerant recovery bottle that has R134a in it or visa versa. That would be the "black death" syndrome. Quick View. You can use this space to go into a little more detail about your company. Thanks so much Bohica - you've save me many more hours of fruitless speculation. R134a is called tetrafluoroethane (HFC). For R12, its mineral oil. I've done the FSM test and with 81F ambient, the vent should be 50F. Later model cars that come with 134A will have 134A only connectors. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? Yep, definately not a meat locker. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? Spray it deep, and let it sit for a few minutes. how to get to disney springs from boardwalk / bb dakota plaid jacket canada / difference between r12 and r134a expansion valve. With tube & fin condensors in MVAC applications there is never "too much" airflow. I cleaned the evap as best I could, if that is what you are getting at. Some say that a chemical reaction can harm the A/C very badly as R134a reacts with mineral oil in some way. R12 is simply too expensive for a 25+ year old A/C system. I have the original (R12) style expansion valve in the Maverick AC system. Is that reasonable?Vent airflow is good, I think. If there is a resource I should read first to save you time, let me know. 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. Is there a difference between a R134a expansion valve and an R12 TXV? Some cars have both an engine coolant temp switch & a refrigerant temp switch, others only the refrigerant switch. Also, it can be used with all types of compressors. Be sure to test @ 1500 to 2000 engine rpm, and record the ambient temp as well. R-12 - yellow R-134a - light blue R-22 - green R-402A - light brown (sand) R-402B - olive R-404A - orange R-407C - medium brown R-410A - rose R-507 - teal J Originally Posted by goldNSX. Thanks for the input. 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. 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.