As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. And I lied about the compressor switches on this car - there are 2 switches on the drier - a temp and a pressure switch. 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. 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. Differences between R-12 and R-134a systems: 1. On the other hand, R12 has a global warming potential of 10,910. ESP when a compressor has frozen. 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. Instead, top off R12 with R134a refrigerant. Some cars have both an engine coolant temp switch & a refrigerant temp switch, others only the refrigerant switch. R404a for freezing of product. Hot coolant migrates up through the core by convection (is that the word? How dumb!I will jumper the aux fan and redo the test. Expansion Valve. Please enter a password for your user account. R134a refrigerant is lighter than R12. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. a 50f delta across the condensor is good, but I suspect that is an idle reading. It slowly gets warmer and warmer in the car, even at highway speeds. R134a is otherwise called 1,1,1,2 Tetrafluoroethane, Florasol 134a, Freon 134a, Norflurane (INN) or HFC 134a. 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 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. Paul:A 1983 240D should have a York compressor on an OEM system. Bookmarks: Digg; del . Hmmmm. . 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. 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. What was the ambient when you took that reading?Jumpering the aux fan is a common thing here in the desert. 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. El juny de 2017, el mateix grup va decidir crear un web deDoctor Who amb el mateix objectiu. Carefully study the chart and compare the following: To a large extent, the choice is up to you. The experimental values of C.O.P.H obtained with the R134a/ester charge were 20.2% 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. How about evacing 1 pound of refrig from the system, and then putting 1 lb of pure R12 back in? Very nice! Energy usage: R134a is less efficient in cooling compared to R12. It's not just the poor performance - the cooling just stops working after a while. = R134a Charge Level. Heres R12 vs. R134a pressure chart. 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. In large application systems, the vapor density of this refrigerant is usually high. The ozone depletion potential of a chemical is a factor that shows the level of degradation itll cause to the ozone layer that surrounds and secures the earth from harmful radiation. The only difference I can imagine would be the recharge connection. 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'. The global warming potential of R134a is 1430. CLUTCH CYCLING SWITCH. In cases such as this, the required capacity value of the expansion valve with R134a is reduced by 30% (correction factor 1.42). Reattach the hose lines using new R134a compatible o-rings, lightly lubricate with compressor oil. If your cars system has a sufficient condenser design and air flow to expel the greater amount of heat extracted by R134a, then by all means you should convert over when the time comes. 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. Spray it deep, and let it sit for a few minutes. The good thing is that after you convert to R134 you can top off the system easily and cheaply. It won't be optimal, though. I found that in the..Maxposition on the control it will have the compressor running all the time. Recomanem consultar les pgines web de Xarxa Catal per veure tota la nostra oferta. It won't be optimal, though. and an evaporator core and expansion valve that are optimized for R134a . I have some experience with auto a/c but not too much. If the system was upgraded by a professional it should have an upgrade sticker. 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 . Different correction factors are applied to other refrigerants. I have just bought gauges. I have one can left, so maybe a plan can be made. It would make a big difference at idle ,in traffic!! Low refrigerating effect per pound: In comparison to other refrigerants, the refrigerating effect of R12 per pound is low. shown for the parallel flow, aluminum condenser that is listed. 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. This allows the refrigerant in the condenser to be void of oil particles. R12 is heavier than R134a and has smaller molecules. Operating Pressure/Temperature Differences The pressure/temperature curves for R-1234yf and R-134a are very similar. The difference really shows up on the high side. The typical scenario here is when the car owner buys an inexpensive retro-fit kit from the local auto parts store. Mine was 61, so the system is not working as it is supposed to. It is perhaps possible to locate a unit with a company that purchases close out or distressed merchandise. and he synthesized R-134a in 1936, 5 years after R-12 was . You may need to adjust the valve in a bit to get desired superheat. 3 ounces? Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. I put one in my old daily driver '79 Chevy tank (r-12), and it really made a difference. The primary function of the design engineer is to make things difficult for the fabricator and impossible for the serviceman. 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 . R1234yf is more environmentally friendly and has a global warming potential of 4. The car never overheats, if that has any import. We ALWAYS want to know the pressure readings! Put a relay on the compressor clutch to the aux fan (I like that idea - makes a lot of sense)How does that sound? -------------------------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! In more serious, it could result in cardiac irregularities or death. The larger line at the expansion valve is the suction line. A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . Bad Car A/C Expansion Valve Symptoms. . 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. Bottom line, R134a simply doesn't cool as well as R12. But, what is considered a good temperature differential across the condensor? Just because the radiator does not boil people assume that the cooling system is ok. Statisicaly your friend was lucky. R134a is called tetrafluoroethane (HFC). 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. The crossover point is approximately at 64F. The value of carbon dioxide is 1. -------------------------"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." If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? If you you dont have the free time to play then you are better off to pay a technician. Be sure to test @ 1500 to 2000 engine rpm, and record the ambient temp as well. R134a and R12 are among the most popular types of refrigerants. They have no moving parts. By: james smith underoath; Comments: 0 . I'm not sure. difference between r12 and r134a expansion valve why is miles raney not on homestead rescue June 21, 2022. manila mayor candidates 2022 Further production of R12 was banned in some developed countries by the Montreal Protocol because of its harsh effect on the ozone layer. Rules governing changing from the former to the latter differ between countries. As for R134a and R1234yf, theres no room for conversion. Besides, you have a greaseisel. An extra half ounce? On this website we are addressing only R134a and not other suggested drop in replacements. 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. R134a refrigerant fittings are different size. Ask Our Pros-Owner Assistance - NO DIY advice will be given. Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. The substitute that we used for R-12 was the new HFC called R-134a. As per their results . It is usually sold under the brand name, Freon 12. Is there a source of valves by, say, eaton number? The crossover point is approximately at 64F. If you have the work done, be sure you find a true "A/C" shop that can make up lines. R12 contains a chemical called chlorine that destroys the ozone layer, thereby causing potential environmental risk. R134a systems operate at higher discharge-side pressures than R12, which can cause compressor seals to leak. 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. 5. Theres no problem with using R134a in a home air conditioning system because it is a hydrofluorocarbon that doesnt cause environmental harm. Use strips of foam to couple the two heat exchangers if necessary.B. 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. R134a requires a different oil. Even though their common major function is to cool the system, they have many differences. Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. 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. Disconnect the two hose lines to the compressor, protect the ends from getting dirty. By after changing just about everything, he got what was termed, satisfactory cooling. . 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. Unfortunately, the R12 refrigerant doesnt always blow cold air. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. Is that reasonable?Vent airflow is good, I think. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. The oil used in R12 and R134a are different and not compatible. Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyers guides, and car and tools comparisons. It is made up of carbon, hydrogen, and fluorine. Swapping the components isnt a herculean task, but recharging the AC is a challenge. Trinary Pressure Switch quantity. But I've read that these car's didn't do too well in the a/c stakes, so that might just be as good as it gets. I think so. 42 (at best) w/ 134A in 2000 isuzu trooper. 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. I don't think it has any air dams or seals, I'll check to make sure. -------------------------"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 catalytic converter is an essential component of your car's emission system that helps save the environment from harmful emissions. June 21, 2022 difference between r12 and r134a expansion valve . Since then, the industry standard has been R134a, which is an efficient replacement. Make sure visiually that no large gaps exist that would allow the air to bypass the condensor on the way to the radiator.B. The larger fitting goes on the discharge port and the smaller fitting goes on the suction line or compressor inlet / suction port. Also, they are mostly used in refrigeration and automotive air conditioning systems. 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.
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