difference between r12 and r134a expansion valve

Some cars have both an engine coolant temp switch & a refrigerant temp switch, others only the refrigerant switch. With the A/c off hi and lo were both at 105psi. -------------------------"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." The best oil that runs well with R134a is PAG oil or Polyalkylene Glycol. R12 is simply too expensive for a 25+ year old A/C system. Spray it deep, and let it sit for a few minutes. The crossover point is approximately at 64F. That's a lot isn't it? On this website we are addressing only R134a and not other suggested drop in replacements. Use strips of foam to couple the two heat exchangers if necessary.B. Most importantly, the oil used in the plant must always be compatible with the refrigerant used. R12 and R22 are both now banned by the EPA in the United States. Took me a while to figure that one out, and how to say that. Below are the major differences between R134a and R12: Chemistry The chemical composition of R12 and R134a differ. All fans must work at 100% of the OEM rating. Well, I'm not sure it is 'fine' - it doesn't cool very well in 95F weather. #19. The evap is hard to get at. By after changing just about everything, he got what was termed, satisfactory cooling. _____ 2012 E350 2006 Callaway SC560 . 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. 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. 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. Besides, R134a refrigerant was manufactured after R12 was banned to help reduce the harshness of the old chemical (R12) on the ozone layer. Is there a graph? bokoen1 hoi4 the great purge / meryl and maks dancing with the stars / difference between r12 and r134a expansion valve. To ensure the right charge, you must fill the new system with between 75 and 85% of the factory-set capacity for optimal cooling. 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. Even though their common major function is to cool the system, they have many differences. Its among the greenhouse gases and will keep adding the current problem of heat not leaving the earths atmosphere. When you add fluorescent tracer dye to with the refrigerant oil it helps to track down leaks that push oil out of the system. Rich Membership Chairman Using R134a in an R12 system will cause the oil not to move with the refrigerant, causing a system failure and probably won't even cool the system well, if at all. 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. Are r12 and r134 fittings different? They can be mounted quite easy,and there is a mounting kit that helps to hang it. The system has been previously converted to R-134a. link to How to cut off a Catalytic Converter. Also, they are mostly used in refrigeration and automotive air conditioning systems. Thread starter goldNSX; Start date 1 August 2009; Tagged . Comparatively, larger R134a molecules should take more space, and a smaller amount might be required. The catalytic converter is an essential component of your car's emission system that helps save the environment from harmful emissions. PaulJerky King -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. difference between r12 and r134a expansion valve It's not just the poor performance - the cooling just stops working after a while. Then again, there are two different expansion valves. It is usually sold under the brand name, Freon 12. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. As per their results . 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). An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback. Stopleak is also risky. Talk about what services you provide. 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. But I don't want to waste your time. It slowly gets warmer and warmer in the car, even at highway speeds. Bookmarks: Digg; del . Can I order a valve based on the original eaton number? R134a is called tetrafluoroethane (HFC). 30 deg is pretty coldSystems generally run between 40 and 43 deg. maintain the A/C of older cars. With the oil leaking out and being told all sorts of things about how these compressors don't have a sump etc, I wanted to be on the safe side. About four or five years ago, I guy with an MB came here with the same problem, that tread was over six pages long. R134a has an ozone depletion potential of 0, implying that it has a slight effect on the ozone layer. Consider using the newer valve, even with 134a stamped on the valve. R12 is heavier than R134a and has smaller molecules. Later model cars that come with 134A will have 134A only connectors. difference between r12 and r134a expansion valve difference between r12 and r134a expansion valve Though - the valve for a 1991 says R12 on it, and for a 1994, it says R-134a. I bought a relay to put on it connected to the compressor clutch. I don't think it has any air dams or seals, I'll check to make sure. Fitting a PF condensor is not rocket science, but it requires some planning. You can spend long evenings reading about the differences between the two refrigerants. It is possible I have 10 ounces (250 ml) in the system. Are you sure you have an R4? We've updated our forums!Click here to visit the new forum, Year: 1991Make: Jaguar Model: XJ6Engine Size: 4.0. After the system has been tested out it should be checked for leaks. 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 . If your car does not have a high pressure cut-out switch in the AC system then youll need to have one installed (call us if you need help). 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. The compressors used by refrigeration plants to compress gas require oil to help lubricate its moving parts. 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. Get to the point where I can walk without crutches2. 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. Generally the system will be initially charged with approximately 80% to 85% of the original amount of R12, using R134a. In most cases, the systems used have varied components, designs, and service ports. Instead, top off R12 with R134a refrigerant. 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. Operating Pressure/Temperature Differences The pressure/temperature curves for R-1234yf and R-134a are very similar. The difference between the two is about 10,000 btu/h. It's helluva humid and hot here in north florida, and I drive around all day for my job. R134a refrigerant fittings are different size. I don't know where it is getting the switch off command, or why the vent temp drops steadily. Warning: "continue" targeting switch is equivalent to "break".Did you mean to use "continue 2"? I'm not sure. Since the hose is the stock hose, you cannot tell what refrigerant is inside. The mechanical fan & clutch should be checked as well. PDF COMPARISON OF Rl34a AND R12 REFRIGERANTS IN A VAPOUR - AIVC 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. Hot coolant migrates up through the core by convection (is that the word? I used a full can of evap cleaner. The original CFC expansion valve used for R12 needs to be replaced with an HFC one for 134a to feed the evaporator correctly. I'm curiousSo there is work to do, ie performance should be able to be improved. 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). Agram a retevis rt22 password i bastrop county district clerk records el material que oferim als nostres webs. The reason is that the vehicles, for instance, manufactured currently configure the engine for R1234yf refrigerant, making no provision for replacement. Refrigerators generally utilize R22, R32, or 410A-based coolants as their cooling agent. I don't want to be chasing ghosts. I think so. difference between r12 and r134a expansion valve 5) A/C System Failure. These two refrigerants are the older types and are not used in newer refrigeration and air conditioning systems. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. The substitute that we used for R-12 was the new HFC called R-134a. The next piece of equipment to track down leaks is a leak sniffer. 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: Sat July 14, 2007 at 10:22 PM by fonebone. 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. It is perhaps possible to locate a unit with a company that purchases close out or distressed merchandise. GWP is a measurement of Greenhouse Gases and their effect on Global Warming. Flush with a garden hose - do not use a high pressure washer - you can bend the fins flat & damage the condensor.B. 1) Look Here at the available sizes of PF condensors.2) Go look at your vehicle's condensor & mounting. He used thermostatic expansion valve and Capillary tube for analysis with R12. Where would I get some basic info on it, I know nothing about it. Can I use the one for the R-12? R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. That way I will have reduced the oil by about 1/3 (assuming the oil is mixed evenly through the system). 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. I recommend replacing the expansion valve when you do the swap. Moreso, it had been banned. That switch should close @ 52c. 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. Or is there always room for improvement, the more the merrier. I put one in my old daily driver '79 Chevy tank (r-12), and it really made a difference. However, R134a is better than R12. . Could that be screwing up the systems performance?Anyway, when I installed the system, the new TXV (is that short for expansion valve?) The condensor airflow drops off as the fan clutch dies slowly. But as there's not a big difference, people say you can suffice with either. . 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. The cable is adjustable at the valve arm. Is the information not applicable to the old Pantera system? Can I use the one for the R-12? R12 to 134A conversion. | Allpar Forums . 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. Tech Talk - Differences between R-1234yf and R-134a - FJC Inc A lower GWP alternative to R-134a had to be found and thus we have the new 1234yf. So you could likely put off buying those new hoses just a bit longer if you wanted. The old compressor used R12 and the new unit will be R134a. I have the original (R12) style expansion valve in the Maverick AC system. ing the expansion valve, a maximum opening superheat of 7F, and a standard factory air test superheat setting. difference between r12 and r134a expansion valve difference between r12 and r134a expansion valve. difference between r12 and r134a expansion valve. The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. Thus, when the system is running, condensing the CO2 is not a problem. 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. and feeds it through an expansion valve. Mine was 61, so the system is not working as it is supposed to. 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. Failure to abide by the EPA regulations can result in expensive fines for either you or your service technician. Thanks again. Since 2010, all home AC systems manufactured use a refrigerant like R134a that has zero ozone depletion potential (ODP). R134a is called tetrafluoroethane (HFC). 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. Not going to mess up your 'do, but you can feel it. 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. |. system of 0.33 TR and refrigerant used was R12. 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!) Some 1993 and older R12 systems aren't as 'compatible' as you'd think to switch over. You may have heard of a friend that did the job himself with borrowed equipment and 12 or 16 ounce cans of refrigerant. R12, on the other hand, is called chlorofluorocarbon (CFC). The experimental values of C.O.P.H obtained with the R134a/ester charge were 20.2% Replacement expansion valve for R134a or R12 A/C refrigerants, with O-ring connections. Bookmarks: Digg; del . 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. This would become an expensive investment for a repair or service station to have unique dedicated equipment for every type of alternative refrigerant. What effect would it have on performance, if any? By noting the ambient temperature you can look up what the preferred high side pressure should be. The name of the oil is Polyol Ester (POE). How an A/C Expansion Valve Works. and an evaporator core and expansion valve that are optimized for R134a . This refers to BTU's (heat) moved per pound of refrigerant moved. R134a and R12 are both refrigerants used in vehicle air conditioning systems. Does it matter - assuming both are new & uncontaminated? 1) Warm Air From Vents. The aux fan seems to be working fine - it switches on occassionally. 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 Please enter a valid email address for yourself. ThanksPaul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. Compared with the cost-performance ratio, R507 is 30-40% . A/C systems designed to use R-12 will cool best when charged with R-12 refrigerant. a 50f delta across the condensor is good, but I suspect that is an idle reading. I have one can left, so maybe a plan can be made. The oil used in R12 systems is not compatible with R134a refrigerant. The adjusted tension of this spring is the determining factor in the opening and closing of the expansion valve. At 2000rpm, windows open, highest fan, hi pressure stabilized at 225 psi, low 25psi.Ambient 81F, vent 61F. Hopefully after you have read this entire page you will have enough information to determine which type of refrigerant is best for you. PDF Experimental analysis of Thermostatic expansion valve, Constant Large temperature difference between expansion valve inlet and outlet oReplace expansion valve Air . In cases such as this, the required capacity value of the expansion valve with R134a is reduced by 30% (correction factor 1.42). Debug the condensor (I am a computer nerd after all!)3. Yes, this was a smokers car. You will be fine with a 134a-compatible TXV running R12. Put a relay on the compressor clutch to the aux fan (I like that idea - makes a lot of sense)How does that sound? By: james smith underoath; Comments: 0 . Questions About Becoming A Professional Member? ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. 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? Expansion Valve Differences R12 vs R134 - Automotive Air Conditioning The difference between R12 and r134a is the BTU carrying capability. There is only a temperature switch on these cars as far as I recall, and it just switches on the aux fan. Bohica, I appreciate your help with this. 05-25-2017 02:14 AM. Shorting the plug for the refrigerant switch should run the fan when the compressor is on. As noted, measure up front as best as you can to get as close to the aftermarket dim. Environmental Impact: When R134a escapes into the atmosphere, it contributes to global warming. A vacuum pump, a refrigerant recover system, quality service gauge set with both low and high side gagues, and much more besides the lessons to learn what to do and what not to do. Components Coils, Heaters, Motors, etc. 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. 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. Bottom line, R134a simply doesn't cool as well as R12. If the water valve is not closing all the way you will have re-heating of the cabin air.The cabin blower was not exactly a powerhouse - it was rated at 200w. -The amount of R-134a needed will typically be 80-90% of the R-12 charge. Very nice! I could easily be over at least 2 - 3 ounces over on the oil. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. The difference between R12 and R134a TEV (exp valves) is primarily the 'superheat'. What Are The Strengths Of Rational Choice Theory, Articles D