difference between r12 and r134a expansion valvedifference between r12 and r134a expansion valve

The substitute that we used for R-12 was the new HFC called R-134a. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. Mark Baker R-401b is the mixture by weight of 61% R22, 11% R-152a and 28% of R-124. 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? Yes, this was a smokers car. The cure is to use the newer R134a compressors is sealing washers that are different thickness. Thus, when the system is running, condensing the CO2 is not a problem. 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 is 11F off the FSM performance graph - vent should be around 50F. Replacement expansion valve for R134a or R12 A/C refrigerants, with O-ring connections. The problem with not being an expert is that you don't know what is important and what's not. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. difference between r12 and r134a expansion valve 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. Look at where the lines will end up. Figure 2 shows the different phases and pressures the refrigerant . 3) A TXV optimized for 134a will be ok with R12. Jun 17, 2011. difference between r12 and r134a expansion valve 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. Even with proper fan operation, missing seals & air dams can effect condensor effeciency. R-401b is the mixture by weight of 61% R22, 11% R-152a and 28% of R-124. Took me a while to figure that one out, and how to say that. However, the supply houses don't indicate a difference. The larger fitting goes on the discharge port and the smaller fitting goes on the suction line or compressor inlet / suction port. If you have a perfectly operating system using R12 you do not have to drop what you are doing and convert to R134a. In large application systems, the vapor density of this refrigerant is usually high. 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. 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 systems used mineral oil, but unfortunately mineral oil doesn't dissolve in R134a. The old compressor used R12 and the new unit will be R134a. A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . 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. The oil is spread all over your system when it is at rest. As noted, measure up front as best as you can to get as close to the aftermarket dim. So that indicates it is cooling well there doesn't it? Thanks again. I used a full can of evap cleaner. 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. 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. Trinary Pressure Switch quantity. The difference between R12 and R134a TEV (exp valves) is primarily the 'superheat'. Statisicaly your friend was lucky. 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 . had writing on the side that said R134a. Crap! B. difference between r12 and r134a expansion valve. R404a for freezing of product. Thomas Jefferson, Thanks,OK, I'm starting to feel a little better about it. With new R12 no longer being manufactured, the market price soared to $100/pound. So if the TXV is OK, and the too much oil situation is not a big problem, then I wonder why the compressor is switching off after about 15 minutes of cooling? GWP is a measurement of Greenhouse Gases and their effect on Global Warming. A discussion of the relationship between valve capacities and superheat set-tings can be found in Bulletin 10-9. With that said, I would source the TXV from another source such as NAPA just to avoid any problems. When the sensor detects the refrigerant leak the sniffers lights glow and the sniffer makes a noise. maintain the A/C of older cars. The next piece of equipment to track down leaks is a leak sniffer. Expansion Valves Catalog E-1, July 2012. Besides, you have a greaseisel. And by matching the correct amount of R134a to use in a given vehicle, correcting the superheat of the expansion valve (if necessary), you can in some manner nearly balance or match the amount of heat drawn out by the evaporator and released by the condenser. Stability: RR12 doesnt disintegrate even under extreme operating conditions. Most importantly, the oil used in the plant must always be compatible with the refrigerant used. By using a qualified a/c shop with the proper equipment you odds are in your favor of having the job done correctly the first time. Whenever its exposed to the environment, it changes to a gas. Thread starter goldNSX; Start date 1 August 2009; Tagged . Performance doesn't seem to have improved. Make sure to get the R12 EXP valve if that is the way you go. To prevent refrigerant loss you should consider replacing your old hose lines with barrier type hose. But, what is considered a good temperature differential across the condensor? Carefully study the chart and compare the following: To a large extent, the choice is up to you. 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. Minor adjustments to the expansion valve and other controls may be necessary for some plans. You do not want to exceed the systems high side recommendations. 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. Additionally, R134a was introduced as a replacement for R22 and R12 in high and medium-temperature refrigeration systems like domestic and commercial chillers. We, the Rxmechanic team, have presented a well-detailed comparison of R134a vs. R12. 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. Jun 19, 2007. Here are the basics for converting a system that does not have a charge of R12, its empty. Do I leave the orignal condensor in, etc?Thanks. I would not do a 134a conversion without a PF condensor. Bookmarks: Digg; del . How to Convert R12 to R22 | eHow I cleaned the evap as best I could, if that is what you are getting at. 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. Hence, the effect of R12 on global warming is up to 10,000 times higher than carbon dioxide. Unfortunately, the R12 refrigerant doesnt always blow cold air. 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. difference between r12 and r134a expansion valve A lower GWP alternative to R-134a had to be found and thus we have the new 1234yf. Though - the valve for a 1991 says R12 on it, and for a 1994, it says R-134a. Well, I'm not sure it is 'fine' - it doesn't cool very well in 95F weather. For instance at 25 F the pressure of R-12 is 24.6 PSI and the pressure of R-134a is 22.1 PSI. That's a lot isn't it? That is for the compressor, drier, expansion valve and condenser. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. With tube & fin condensors in MVAC applications there is never "too much" airflow. The car never overheats, if that has any import. Not osmosis, but you know what I mean). 4) Repeat step 2, making sure it will fit. Thanks so much Bohica - you've save me many more hours of fruitless speculation. I'm also thinking maybe I should go to R134 - it might work better with the right amount of oil and the correct expansion valve. Your average garage that works on a/c on the side probably would not have this. VerticalScope Inc. All Rights Reserved. If there is a resource I should read first to save you time, let me know. CLUTCH CYCLING SWITCH. 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. This allows the refrigerant in the condenser to be void of oil particles. Use a strong surfactant like Simple Green or Zep Citrus, and soak the fins on the condensor. Is that why expansion valves are specific to R12 or R134A? 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. 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. The original expansion valves work very well with R134a. 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. It runs between the condenser outlet, receiver/drier unit and expansion valve at the firewall. Safe but sorry! in /nfs/c05/h04/mnt/113983/domains/toragrafix.com/html/wp-content . Amazon.com: 134a Valve Some compressor manufacturers or OEMs suggest PAG type oil for R134a. This refers to BTU's (heat) moved per pound of refrigerant moved. Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. 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. Lets take you through the advantages, disadvantages, and differences of these two refrigerants a detailed comparison including R12 vs R134a performance. We ALWAYS want to know the pressure readings! What is needed? of refrigerant insulation tape. Make sure to wear safety gloves, goggles, and shoes when theres a possibility of exposure to the chemical (R134a). ing the expansion valve, a maximum opening superheat of 7F, and a standard factory air test superheat setting. If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? The OEM spec is 2300 rpm @ 12.6v (engine stopped fully charged battery). You'll want the expansion valve matched to whatever refrigerant you're using. Biggest you can fit in there is best. I'm just trying to help you avoid headaches in the long run. Dimensioning of refrigeration components - part 2 - Danfoss I found that in the..Maxposition on the control it will have the compressor running all the time. El juny de 2017, el mateix grup va decidir crear un web deDoctor Who amb el mateix objectiu. Also, R134a cylinders are light-blue in color. This means that it has a high potential of causing depletion to the ozone layer. Putting R12 into a R134 vehicle | AnandTech Forums: Technology difference between r12 and r134a expansion valve. I just got some hi/lo side gauges so I'm going to take readings, if they are needed. 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. R134a vs. R12 - Griffiths If you you dont have the free time to play then you are better off to pay a technician. Its cylinders are colored white. Its not that difficult but the procedures of evacuation, charging and testing should be done by a licensed a/c technician that is experienced with R134a and your particular car. I put one in my old daily driver '79 Chevy tank (r-12), and it really made a difference. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? R134a requires a different oil. This would become an expensive investment for a repair or service station to have unique dedicated equipment for every type of alternative refrigerant. It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. At this point it is time to make an appointment with the a/c shop. 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. CR4P). 4 Stars & Up & Up; 3 Stars & Up & Up; 2 Stars & Up . A thermostatic expansion valve (TXV) (see Figure 1) is a refrigeration and air conditioning throttling device that controls the amount of refrigerant liquid injected into a system's evaporatorbased on the evaporator outlet temperature and pressurecalled the superheat. Skin contact: If the R134a (liquid) comes in contact with your skin, it could cause a burn. I bought a relay to put on it connected to the compressor clutch. It is a haloalkane and hydrofluorocarbon (HFC) refrigerant that has thermodynamic properties, potential global warming for one hundred years, and insignificant ozone depletion. 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!) I had to vaccum the system for 2 hours and recharge 4 oz of PAG oil plus 36 oz of 134A freon (3 cans). When you add fluorescent tracer dye to with the refrigerant oil it helps to track down leaks that push oil out of the system. Can I use the one for the R-12? It is usually sold under the brand name, Freon 12. Does it matter - assuming both are new & uncontaminated? For instance you can evacuate FRIGC FR-12 into a refrigerant recovery bottle that has R134a in it or visa versa. R1234yf. For example, if your system originally had 36 ounces of R12 then you multiply that by .80 and you have 29 ounce of R134a. Are you sure you have an R4? bokoen1 hoi4 the great purge / meryl and maks dancing with the stars / difference between r12 and r134a expansion valve. 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. You'll get marginally better performance out of the change as the expansion valve is matches the refrigerant characteristics. I think the way to go here is1. There is more to check.The evaporator must be clean as well as the condensor - was this a smoker's car?You should check the water control valve for the heater core. It won't be optimal, though. They examined the two configurations of capillary tubes i.e. Depending on which circuit diagram fits your car (cough, no vin list exists) you have either one or two switches controlling the aux fan. Refrigerators generally utilize R22, R32, or 410A-based coolants as their cooling agent. To ensure the right charge, you must fill the new system with between 75 and 85% of the factory-set capacity for optimal cooling. CONCLUSIONS The differences in the theoretical C.O.P.H calculated for R12 and R134a are consistent with values quoted in the literature. 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. 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. -------------------------"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." UNDERSTANDING A/C Everything You Need To Know - Classic Auto Air I've straightened the fans I can and sprayed simple green on it, let it soak then hosed it down well. The major reason for the replacement of R12 with R134a was to curb future greenhouse effects. Interestingly, theres one oil type that works perfectly with both types of refrigerants. You should keep in mind that recharging your air conditioner improperly could result in more serious damage. Hence, let us continue to fix it. The smoking question & vent airflow indicate that the evaporator is fairly clean - and you are aware of the importance of that.The heater valve stops the flow, but there is always some conduction heating. We mention using ester type refrigerant oil. AFAIK, there is no clutch on the engine fan on the 240D. Even though their common major function is to cool the system, they have many differences. Thanks for the input. Helical and Serpentine coils. Flush with a garden hose - do not use a high pressure washer - you can bend the fins flat & damage the condensor.B. look at the difference! Don't like the sound of custom parallel condensor. The compressors used by refrigeration plants to compress gas require oil to help lubricate its moving parts. As per their results . I have just bought gauges. Low refrigerating effect per pound: In comparison to other refrigerants, the refrigerating effect of R12 per pound is low. . But as there's not a big difference, people say you can suffice with either. Below are the major differences between R134a and R12: The chemical composition of R12 and R134a differ. A slow loss of cooling at city speeds is usually related to condensor capacity & airflow issues.You could improve the cooling capacity by replacing the condensor with a high effeciency parallel flow unit. Big . The approval is very legal one, governed by the U.S. EPA. Any advice appreciated. 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. However, you can convert R12 to R134a by yourself, save money and keep all the tools purchased. Have a look in the FAQ Section, and look for "Fan clutches & testing them". If you have 10 ounces of oil in the system, that is contributing to the poor performance as well. 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). You may be just fine on oil - it depends on what compressor you have & how much oil you put in.A T/C is short for Thermocouple. 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. Temp switch works the aux fan. What effect would it have on performance, if any? "Howdy, Folks!" The mechanical fan & clutch should be checked as well. The AC usually does not work at all. R134a and water have the same abilities to change the state but R134a can do this more rapidly and at a much lower temperature than water. 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. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. 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 Heres R12 vs. R134a pressure chart. 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. Hopefully after you have read this entire page you will have enough information to determine which type of refrigerant is best for you. When I compare parts, 93 uses one part number and 94 has a different part number. Some 1993 and older R12 systems aren't as 'compatible' as you'd think to switch over. System has been working fine for a year. Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. That switch should close @ 52c. Neuro spine Super Speciality Clinic - Above Apollo Pharmacy, Bangarpet Circle, Kolar - Bangarpet Road, Kolar Town. It would make a big difference at idle ,in traffic!! I am ordering new parts, and planning to convert my system to R-134a. James10952001. It is possible I have 10 ounces (250 ml) in the system. Further production of R12 was banned in some developed countries by the Montreal Protocol because of its harsh effect on the ozone layer. 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? We've updated our forums!Click here to visit the new forum, Year: 1991Make: Jaguar Model: XJ6Engine Size: 4.0. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. Just leave it alone for now. (The .133 is the 300D Turbo).So, what does your compressor look like?B. Reattach the hose lines using new R134a compatible o-rings, lightly lubricate with compressor oil. Is there a graph? absorb by the evaporator to insure all liquid refrigerant entering the evaporator. There is only a temperature switch on these cars as far as I recall, and it just switches on the aux fan. In more serious, it could result in cardiac irregularities or death. R 134A is designed for the high demands of an automobile AC and cannot be used on refrigerators due to pressure differences. The original rubber a/c hose lines in your car will leak out R12 through the hoses lining. Even if the system leaks, repairing the leaks and recharging it with R-12 is usually the best repair alternative. Its chemical symbol is CCl2F2. A slow loss of cooling at city speeds is usually related to condensor capacity & airflow issues. So, instead of using R12, other better options include R401b, R134a, R401a, etc. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. In the automotive world, the replacement for R12 was R134a. Large temperature difference between expansion valve inlet and outlet oReplace expansion valve Air . Paul:A 1983 240D should have a York compressor on an OEM system. I had a 1991 BMW switched to 134a by just changing the low pressure charging valve, flushing and refilling with 134 (maybe with 10% . If the system was upgraded by a professional it should have an upgrade sticker. 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. How thermostatic expansion valves work | Danfoss Safety: R134a is safe to use as its non-flammable and cant explode. Hot coolant migrates up through the core by convection (is that the word? Right now you know you have a bit too much, but with a CR4P compressor this is an insurance policy. Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. 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. On the other hand, R12 has a global warming potential of 10,910. R134a and R12 are both refrigerants used in vehicle air conditioning systems. Could that be screwing up the systems performance?Anyway, when I installed the system, the new TXV (is that short for expansion valve?) 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. 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. You can also check the Aux fan in your case. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. The R134a compressor has a 1/8" step in on the high side port. and an evaporator core and expansion valve that are optimized for R134a .