An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback. In addition, R134a refrigerants are not only used in auto air conditioners, they can be used in freezers, aerosol cans, and refrigerators. 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. 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. R12 contains a chemical called chlorine that destroys the ozone layer, thereby causing potential environmental risk. Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). 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. Also, R134a cylinders are light-blue in color. VerticalScope Inc. All Rights Reserved. The original expansion valves work very well with R134a. . I dont know why the cost difference between compressors is so huge, though. Rules governing changing from the former to the latter differ between countries. At 40, it is 35psi, which is a difference of 8.9psi. In a comparison between R12 vs R134a vs R1234yf, R1234yf will pass as the best refrigerant. Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. This is because R134a. Its chemical symbol is CH2FCF3. I have just bought gauges. I remember I had the wrong seals and it leaked some oil, so I put some more in.Bohica - I tested the pressures. Temp switch works the aux fan. 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. How dumb!I will jumper the aux fan and redo the test. The safe high side pressures are determined with a PT (pressures and temperatures) chart. At least you do not have 16 ounces in there ( yup seen it before).For now, straighten all of the fins that you can, clean the condensor well, and re-test with the aux fan running. If the system was upgraded by a professional it should have an upgrade sticker. Is there a difference in the expansion valve for R12 as opposed to R-134a? A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. The value of carbon dioxide is 1. The P H and T cond,sat of the HR12 at a T oa of 40 C were higher than that of the R134a, resulting in a higher P e than that for the R134a. Flush with a garden hose - do not use a high pressure washer - you can bend the fins flat & damage the condensor.B. and an evaporator core and expansion valve that are optimized for R134a . 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. At 2000rpm, windows open, highest fan, hi pressure stabilized at 225 psi, low 25psi.Ambient 81F, vent 61F. Stay home and grill your own steaks and stir your own martini. I'm having the same concern. Usually, mechanics charge around $200 for conversion. It runs between the condenser outlet, receiver/drier unit and expansion valve at the firewall. a 50f delta across the condensor is good, but I suspect that is an idle reading. Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. Its chemical symbol is CH2FCF3. The chemical composition of R12 and R134a differ. So to keep things simple and to avoid controversy and politics we have R134a. Reattach the hose lines using new R134a compatible o-rings, lightly lubricate with compressor oil. Thus, when the system is running, condensing the CO2 is not a problem. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. Also, since R134a uses synthetic oil, it has a low global warming potential, unlike R12 which uses mineral oil which poses a negative environmental impact. A/C Expansion Valve Replacement Cost. Bookmarks: Digg; del . That way I will have reduced the oil by about 1/3 (assuming the oil is mixed evenly through the system). Sense ells no existirem. R404a is a zeotropic blend with a temp glide , because of the mixture of 2 or more refrigerants. R12, on the other hand, has an ozone depletion potential of 1, implying that it can damage the ozone layer. sparkee said: Thanks for the Service Bulletin. Generally, the new amount is 75-85% of the quantity advised by the manufacturer. Don't like the sound of custom parallel condensor. When the temperature is reduced to-7C or below, the plants ability to cool the airdrops significantly. Pray I can let some oil out of the compressor without losing my precious R12. We sometimes use a relay switched from the compressor clutch to run fans. 5. You do not need to replace the expansion valve in most cases. June 21, 2022 difference between r12 and r134a expansion valve . Thomas Jefferson, Thanks,OK, I'm starting to feel a little better about it. But as there's not a big difference, people say you can suffice with either. I think the way to go here is1. 4.R404A R134a increased mass transfer resistance to reduce the transmission chamber heat coefficient, while R507 heat transfer coefficient is higher than R404A. in /nfs/c05/h04/mnt/113983/domains/toragrafix.com/html/wp-content . 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. R12 Expansion Valve = 201 830 06 84 R134A Expansion Valve = 201 830 04 84 Is there a difference after all? 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. Even if the system leaks, repairing the leaks and recharging it with R-12 is usually the best repair alternative. Then again, there are two different expansion valves. Performance doesn't seem to have improved. 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. You may have heard of a friend that did the job himself with borrowed equipment and 12 or 16 ounce cans of refrigerant. Electric fans do wear out. Paul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. Besides, you have a greaseisel. Replacement expansion valve for R134a or R12 A/C refrigerants, with O-ring connections. Recharge the compressor with a/c ester oil and a tracer dye. And I lied about the compressor switches on this car - there are 2 switches on the drier - a temp and a pressure switch. 3) A TXV optimized for 134a will be ok with R12. This may be the source of your oil confusion. Is there a difference between a R134a expansion valve and an R12 TXV? Gnats & mosquitos will clog deep. 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. An extra half ounce? 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!) As for R134a and R1234yf, theres no room for conversion. we convert older systems where i work all the time and they work fine. difference between r12 and r134a expansion valve. In cases such as this, the required capacity value of the expansion valve with R134a is reduced by 30% (correction factor 1.42). Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. That would be the "black death" syndrome. "Jerky Locker" LMAO I am using that one in the future!Florida = BUGS! 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 . Before landing on the debate of R134 vs R12 you should know that both R134a and R12 are AC refrigerants types used in refrigeration and air conditioning systems. Most vehicles manufactured before 1993 have the R12 A/C system. Yep, definately not a meat locker. With R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. The difference really shows up on the high side. Also called the orifice tube. and he synthesized R-134a in 1936, 5 years after R-12 was . But R22 is almost equally damaging. Is it exponential, squared? system of 0.33 TR and refrigerant used was R12. El juny de 2017, el mateix grup va decidir crear un web deDoctor Who amb el mateix objectiu. 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. Unfortunately, the oil only mixes with the refrigerant as a liquid. R-12 to R-134a Conversion. It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. 4 Stars & Up & Up; 3 Stars & Up & Up; 2 Stars & Up . We ALWAYS want to know the pressure readings! System has been working fine for a year. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. 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. 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. 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. ). BTW, I use a stick thermo in the vents and the laser on the condenser. The name of the oil is Polyol Ester (POE). 1.5 ounces - hmmm. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. CLUTCH CYCLING SWITCH. We say generally because the vehicle manufacturer may have a formula already worked out for the R134a conversion process. Nice to use new gadgets! Though I have seen em run as cold as 12 deg F. If the thermo switch is malfunctioning. Or is there always room for improvement, the more the merrier. R1234yf is more environmentally friendly and has a global warming potential of 4. The oil is spread all over your system when it is at rest. Instead of using R12, its preferable to use R134a because it is very easy to find in the market, its sold at an affordable price, and is environmentally friendly. It cycles on off in med (or low for that matter)Gotta tell ya. Table 1 summarizes the technical characteristics of three potential R134a alternatives. But as there's not a big difference, people say you can suffice with either. Paul:A 1983 240D should have a York compressor on an OEM system. 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. 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. There is only a temperature switch on these cars as far as I recall, and it just switches on the aux fan. Thus, when the system is running, condensing the CO2 is not a problem. 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. For R12, its mineral oil. Operating Pressure/Temperature Differences The pressure/temperature curves for R-1234yf and R-134a are very similar. R134a is called tetrafluoroethane (HFC). This leads me to labor over every small decision. If you have 10 ounces of oil in the system, that is contributing to the poor performance as well. R 134A is designed for the high demands of an automobile AC and cannot be used on refrigerators due to pressure differences. 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. This can be very very expensive. Jun 19, 2007. 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. That is for the compressor, drier, expansion valve and condenser. I'm curiousSo there is work to do, ie performance should be able to be improved. R134a was selected as a replacement refrigerant for R12 because R12 contains chlorine and has a major effect to ozone layer depletion. R134a Refrigerant Recharge Kit with BPV31 Bullet Piercing Valve and R134a Quick Coupler, R134a/R-12/R-22 Freon Refrigerant Hose Can Tap Kit for A/C System - Easy to use. 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. Just because the radiator does not boil people assume that the cooling system is ok. 1) Warm Air From Vents. 30 deg is pretty coldSystems generally run between 40 and 43 deg. The first vehicle that used the R1234yf refrigerant was the 2013 Cadillac XTS. _____ 2012 E350 2006 Callaway SC560 . It is perhaps possible to locate a unit with a company that purchases close out or distressed merchandise. This is an electronic tool that sucks in air through a tube and across a sensor. The larger fitting goes on the discharge port and the smaller fitting goes on the suction line or compressor inlet / suction port. Any suggestions, or do you need to know the hi/lo readings? What is needed? When ever possible you should ask the technician to note the same information on your repair bill and keep a copy in your glove box for future reference. I used a full can of evap cleaner. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. But as there's not a big difference, people say you can suffice with either. After the optimum refrigerant charge is determined the car should be test driven to check for performance of the system. 3) A/C Compressor Always On. 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). It would make a big difference at idle ,in traffic!! Rules governing changing from the former to the latter differ between countries. I'm not sure. Until 1995, most cars with air conditioning used R-12 Freon refrigerant which has shown to have an environmental impact. I would not do a 134a conversion without a PF condensor. Just had knee surgery yesterday, so I"M not exactly hopping around too well. Further production of R12 was banned in some developed countries by the Montreal Protocol because of its harsh effect on the ozone layer. Comparatively, larger R134a molecules should take more space, and a smaller amount might be required. It is usually sold under the brand name, Freon 12. It is made up of carbon, hydrogen, and fluorine. 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. Talk about what services you provide. Get to the point where I can walk without crutches2. Can I order a valve based on the original eaton number? look at the difference! Trinary Pressure Switch $ 39.99. 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 . The difference between the two is about 10,000 btu/h. Edited: Sat July 14, 2007 at 10:22 PM by fonebone. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores. This refers to BTU's (heat) moved per pound of refrigerant moved. Biggest you can fit in there is best. Not osmosis, but you know what I mean). Environmental Impact: When R134a escapes into the atmosphere, it contributes to global warming. . There are three different refrigerants officially sanctioned by the EPA for automotive usage: r-12, r-. difference between r12 and r134a expansion valvewarning signs for a deteriorating patient with covid 19 infection 2022.07.03 18:36 18:36 5) A/C System Failure. 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. R12 is highly destructive to the earths ozone layer. I don't want to be chasing ghosts. 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. If the charge is low the compressor will cycle on/off in the max AC position. 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. What effect would it have on performance, if any? . The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. Well, I'm not sure it is 'fine' - it doesn't cool very well in 95F weather. 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 analysis focuses on Coefficient of Performance for . (You must log in or sign up to reply here. R134a and R12 are both refrigerants used in vehicle air conditioning systems. 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. Expansion Valves Catalog E-1, July 2012. R134a is called tetrafluoroethane (HFC). Unfortunately, the R12 refrigerant doesnt always blow cold air. As an example, let's say the R12 charge specification is listed at 2 lbs. With R134a you do not rely on the site glass. video clubhouse baseball; nick fairley draft profile; ben davis work pants The exact amount will vary with each car. This kit comes complete with Expansion valve, o-ring kit, and 1ft. Compressor. As noted, measure up front as best as you can to get as close to the aftermarket dim. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. Minor adjustments to the expansion valve and other controls may be necessary for some plans. Automotive Replacement Expansion Valves & Parts; Industrial & Scientific; Customer Reviews. #13. The cost of recharging the air conditioner is between $150 to $500. Recomanem consultar les pgines web de Xarxa Catal per veure tota la nostra oferta. 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. The problem with not being an expert is that you don't know what is important and what's not. 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. If you have a York, and it is equipped with service valves, you can check & adjust the oil level without discharging the system. . might be due to charge or different compressor and age. It slowly gets warmer and warmer in the car, even at highway speeds. Can I just use an adapter and save $200? The global warming potential of R134a is 1430. 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. 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. Also, if you want to know what happens if you put R134a in an R12 system, you should first confirm if the R12 system can be replaced or if the refrigerants can be mixed. Answer: OK, I'll bite. 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. Therefore, its most suitable for both commercial and domestic environments. Have a look in the FAQ Section, and look for "Fan clutches & testing them". Are you sure you have an R4? Please enter a valid email address for yourself. If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? I had a pair on my SAAB that seemed ok - but new ones ran 20% faster!Your best clue to airflow issues is a 60 mph test. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. It didn't seem too dirty though - I don't think it is the problem, but I could be wrong. Concentration level: The R134a vapor dilutes the oxygen concentration in the air to a low level, thereby causing harm. Welcome to rxmechanic.com. The system has been previously converted to R-134a. All pre-97 XJs use systems with the same basic operating principle, although the parts do change a bit. 2001-2023 Griffiths Technical Inc. All Rights Reserved. The problem with using an approved alternative refrigerants other than R134a is that when the system is serviced it requires certain types of fittings, labels and dedicated equipment. Though - the valve for a 1991 says R12 on it, and for a 1994, it says R-134a. shown for the parallel flow, aluminum condenser that is listed. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. Please enter the name by which you would like to log-in and be known on this site. R134a is NOT less efficient than R12 Actually R134a is more efficient. If not, you just don't know unless a test is performed. Hmmmm. Blows pretty hard on full. 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. There are R134a specific valves that operate at a slightly different pressure, but not for any "old" automotive application that I'm aware of. It is made up of carbon, hydrogen, and fluorine. Only show this user. If you are replacing other system components, such as condensers, driers or hoses, you may need to add more a/c refrigerant oil to the system. . Look deep into the fins. In large application systems, the vapor density of this refrigerant is usually high. 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. Put a relay on the compressor clutch to the aux fan (I like that idea - makes a lot of sense)How does that sound?
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