You'll get marginally better performance out of the change as the expansion valve is matches the refrigerant characteristics. 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. Right now you know you have a bit too much, but with a CR4P compressor this is an insurance policy. After the system has been tested out it should be checked for leaks. Its chemical symbol is CH2FCF3. Interestingly, theres one oil type that works perfectly with both types of refrigerants. I've got a ball valve I'm going to put in the coolant line before the coolant goes through the firewall to the core. 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. 1) Look Here at the available sizes of PF condensors.2) Go look at your vehicle's condensor & mounting. There are R134a specific valves that operate at a slightly different pressure, but not for any "old" automotive application that I'm aware of. (On firewall where A/C lines go into cab.) Replacement expansion valve for R134a or R12 A/C refrigerants, with O-ring connections. Big . 10,000BTU conduction heating? They can be mounted quite easy,and there is a mounting kit that helps to hang it. Theres no doubt that R12 refrigerant is one of the first compounds manufactured for the air conditioning and refrigeration world, but it had to be banned. I'm putting r12 back in my system, but all of the valves I can for the application (1990 jeep grand wagoneer) say r134a on them. The car never overheats, if that has any import. Condensers designed to release greater amounts of heat help to expel the greater amount of heat which R134a removes from the cars interior. The pressure at low temperatures is nearly the same between 12 and 134a. I just got some hi/lo side gauges so I'm going to take readings, if they are needed. R-134a XV for R-134a use. Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. 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. Add to cart. They examined the two configurations of capillary tubes i.e. Further production of R12 was banned in some developed countries by the Montreal Protocol because of its harsh effect on the ozone layer. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. I'm curiousSo there is work to do, ie performance should be able to be improved. Below are the major differences between R134a and R12: The chemical composition of R12 and R134a differ. What effect would it have on performance, if any? Biggest you can fit in there is best. shown for the parallel flow, aluminum condenser that is listed. Different correction factors are applied to other refrigerants. 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. The oil used in R12 systems is not compatible with R134a refrigerant. June 21, 2022 difference between r12 and r134a expansion valve . These efforts to balance the system can not be realized if there are problems within the a/c system, such as: poor performing compressor, dirty condenser or poor air flow through the condenser, malfunctioning expansion valve, water or air in the system, improperly operating fresh air or heat input in the climate-air mixing system. The only difference I can imagine would be the recharge connection. -------------------------Just another brick in the wallHad a little mule I fed him castor oil and every time he jumped the fence he fertilized the soil, The older expansion valves were filled with the refrigerant they were used with, the replacement valves (today) are filled with a different chemical to work with both refrigerants..Hope this helps-------------------------ChickEmail: Chick---------------------------------------------Freedoms just another word for nothing left to lose, I believe the optimum supercool setting will vary slightly between an expansion valve for an R12, as compared to R134a, system. Ensure you contact a professional mechanic to do the work for you so you dont end up incurring more costs for yourself. R134a has the chemical formula CF3CH2F and is known as tetrafluoroethane. 30 deg is pretty coldSystems generally run between 40 and 43 deg. All fans must work at 100% of the OEM rating. I'll put the relay on for that. "Jerky Locker" LMAO I am using that one in the future!Florida = BUGS! I have one can left, so maybe a plan can be made. 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. So I probably put the highest suggested amount in to be safe. A comparison between R12 vs. R134a temperature will show that R12 has a higher temperature than R134a. Figure 2 shows the different phases and pressures the refrigerant . We recently created this blog site to enable us to share our knowledge with other automotive mechanics and car owners. When the temperature is reduced to-7C or below, the plants ability to cool the airdrops significantly. The newer valves and switches will work with both refrigerants. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyers guides, and car and tools comparisons. ThanksPaul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. The first vehicle that used the R1234yf refrigerant was the 2013 Cadillac XTS. _____ 2012 E350 2006 Callaway SC560 . -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. Most importantly, the oil used in the plant must always be compatible with the refrigerant used. The R134a compressor has a 1/8" step in on the high side port. My turn to LOL - greasiesel! R134a is called tetrafluoroethane (HFC). In a car ac, using this type of freon 20 years ago was difficult. Your average garage that works on a/c on the side probably would not have this. 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. Not osmosis, but you know what I mean). Besides, its technology has been tested and trusted. How is the vent airflow?I would jumper the aux fan & check the performance. Besides, you have a greaseisel. Related products. R134a has an ozone depletion potential of 0, implying that it has a slight effect on the ozone layer. In the automotive world, the replacement for R12 was R134a. Jun 17, 2011. 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. Look at where the lines will end up. It is mixed with the freon for the most part, and does accumulate in all components in small amounts. . The mechanical fan & clutch should be checked as well. The money you will save by will pay for the R12. 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. But R22 is almost equally damaging. compressor, condenser, evaporator and expansion valve are specifically designed for use with R134a. Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). With new R12 no longer being manufactured, the market price soared to $100/pound. A final difference is that most (though not all) R-1234yf cars will have a Suction Line Heat Exchanger. You are indeed 20% out of the OEM spec for cooling. Until 1995, most cars with air conditioning used R-12 Freon refrigerant which has shown to have an environmental impact. An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback. They might say for instance, add 3-4 oz of oil to the compressor, 1 oz of oil for when you replace a drier, 2 oz oil for the evaporator and so on. Answer: OK, I'll bite. how to get to disney springs from boardwalk / bb dakota plaid jacket canada / difference between r12 and r134a expansion valve. R12 is CFC: Even though R12 is one of the most commonly used refrigerants, it is CFC. Even if the system leaks, repairing the leaks and recharging it with R-12 is usually the best repair alternative. What is usually sniffed are all the connections in the system: hoses and compressor, condenser, drier, expansion valve and evaporator fittings. Moreso, it had been banned. Discussion in 'Technical' started by Jsarnold, May 25, 2012. I put in a new (not reman) compressor (R4 I believe it is) in my merc 240D, new drier, new expansion valve, new o-rings, nylog. Some cars have both an engine coolant temp switch & a refrigerant temp switch, others only the refrigerant switch. Operating Pressure/Temperature Differences The pressure/temperature curves for R-1234yf and R-134a are very similar. 4) Inconsistent Airflow. 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. Consider using the newer valve, even with 134a stamped on the valve. Recharge the compressor with a/c ester oil and a tracer dye. System has been working fine for a year. I don't recall all the details, but starts off with the largest parallel flow condenser and improved fans. The experimental values of C.O.P.H obtained with the R134a/ester charge were 20.2% The difference really shows up on the high side. 4) Repeat step 2, making sure it will fit. The best replacement for R134a is R1234yf, while R12 refrigerant replacement was R134a. 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. Make sure to wear safety gloves, goggles, and shoes when theres a possibility of exposure to the chemical (R134a). BTW, I use a stick thermo in the vents and the laser on the condenser. Even though their common major function is to cool the system, they have many differences. 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. 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. 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. The compressors used by refrigeration plants to compress gas require oil to help lubricate its moving parts. 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. Though you can purchase 12 or 16 ounce cans of R134a from local retailers it is very difficult to measure out the correct amount into your system. We consider the the various types alternative refrigerants that are illegal or not approved to be in two sectors: non-flammables and flammables. Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. Rules governing changing from the former to the latter differ between countries. The aux fan didn't switch on though and I didn't check the high side temperature. At the time I thought nothing of it, but now I am thinking maybe that is contributing to the system not working as well as it could. Lasers don't do well on vent temps, a stick thermometer is better in that application. Spray it deep, and let it sit for a few minutes. However, if it is taken close to a fire flame or any electrical heating element, it disintegrates into toxic products. Its duty is to convert toxic gasses produced by the engine into A brake cleaner is a powerful solvent for cleaning dirt from the brakes and other car components. Safety: R134a is safe to use as its non-flammable and cant explode. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. 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. Tamb oferim en VOSC el contingut daquestes sries que no es troba doblat, com les temporades deDoctor Who de la 7 en endavant,les OVA i els especials de One Piece i molt ms. To bless the system the technician should attach a R134a sticker somewhere in the engine compartment to note the car is using R134a. You may have heard of a friend that did the job himself with borrowed equipment and 12 or 16 ounce cans of refrigerant. Can I order a valve based on the original eaton number? Replied by Rich928 on topic R12 or R134a. I'm having the same concern. 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 . . Measure what you have now.3) Go back to the page in step one, and find the largest condensor you can put in your vehicle. This may be the source of your oil confusion. This is 11F off the FSM performance graph - vent should be around 50F. Refrigerators generally utilize R22, R32, or 410A-based coolants as their cooling agent. This would become an expensive investment for a repair or service station to have unique dedicated equipment for every type of alternative refrigerant. 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. The MB chart shows 360 psi with R12 in some conditions. However, R134a is better than R12. This means that it has a high potential of causing depletion to the ozone layer. The aux fan seems to be working fine - it switches on occassionally. Then at least I'd know really where I am on it. R-12 to R-134a Conversion. The Main change in the system is the expansion valve. Most of all the differences gravitate to longevity, functionality, and safety. -------------------------"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." Replace the drier with a drier that has a desiccant that is R134a compatible, use new R134a o-rings. Thread starter goldNSX; Start date 1 August 2009; Tagged . Just had knee surgery yesterday, so I"M not exactly hopping around too well. Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. I recommend replacing the expansion valve when you do the swap. It is usually sold under the brand name, Freon 12. What effect would it have on performance, if any?At the moment, the ac is acting up - will work fine for about 15 minutes and then slowly the vent temperatures rise until the compressor switches off. Blows pretty hard on full. Kommentare . Automotive Replacement Expansion Valves & Parts; Industrial & Scientific; Customer Reviews. ESP when a compressor has frozen. 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. A/C systems designed to use R-12 will cool best when charged with R-12 refrigerant. maintain the A/C of older cars. If the system was upgraded by a professional it should have an upgrade sticker. Like say half a can or so recharge come springtime warm weather or something. . R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. Miscibility with oil: R12 can be mixed with the compressor oil no matter the operating condition. Als nostres webs oferimOne Piece,Doctor Who,Torchwood, El Detectiu ConaniSlam Dunkdoblats en catal. Swapping the components isnt a herculean task, but recharging the AC is a challenge. I had a 1991 BMW switched to 134a by just changing the low pressure charging valve, flushing and refilling with 134 (maybe with 10% . Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? Can I just use an adapter and save $200? Compared with the cost-performance ratio, R507 is 30-40% . |. video clubhouse baseball; nick fairley draft profile; ben davis work pants We've updated our forums!Click here to visit the new forum, Year: 1983Make: MercedesModel: 240DEngine Size: 2.4Refrigerant Type: R12Ambient Temp: 90Pressure Low: 35Pressure High: ?Country of Origin: United States, Hi, this is my first post, so please take it easy on the noob. I had to vaccum the system for 2 hours and recharge 4 oz of PAG oil plus 36 oz of 134A freon (3 cans). Performance doesn't seem to have improved. What was the ambient when you took that reading?Jumpering the aux fan is a common thing here in the desert. #13. I have just bought gauges. 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. 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. What is a T/C?4. Yep, definately not a meat locker. R134a refrigerant is lighter than R12. Inasmuch as R134a has a global warming potential thats over 1000 times more threatening than carbon dioxide, its better than R12. Some say that a chemical reaction can harm the A/C very badly as R134a reacts with mineral oil in some way. Electric fans do wear out. 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. 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. Any ideas from the info above? Environmental Impact: When R134a escapes into the atmosphere, it contributes to global warming. It runs between the condenser outlet, receiver/drier unit and expansion valve at the firewall. Is there a graph? Stay home and grill your own steaks and stir your own martini. The flammables have hydrocarbons. Is the information not applicable to the old Pantera system? -------------------------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 most cases, the systems used have varied components, designs, and service ports. Where would I get some basic info on it, I know nothing about it. 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. The catalytic converter is an essential component of your car's emission system that helps save the environment from harmful emissions. I am ordering new parts, and planning to convert my system to R-134a. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores. A/C Expansion Valve Replacement Cost. 3 ounces? The condensor airflow drops off as the fan clutch dies slowly. But, if your old compressor has lock-up or if your current expansion valve is not functional it would wise to replace the expansion valve with a valve designed for R134a. They have no moving parts. R134a and R12 are among the most popular types of refrigerants. When I compare parts, 93 uses one part number and 94 has a different part number. Is that why expansion valves are specific to R12 or R134A? It won't be optimal, though. Here are the basics for converting a system that does not have a charge of R12, its empty. Also, would a genuine R12 TXV be better, or is it too marginal to worry about?I think I should do the FSM test for performance - they have a graph with ambient temp and a/c temp. But R22 is almost equally damaging. VerticalScope Inc. All Rights Reserved. It was later found that R-134a had a very high Global Warming Potential, or GWP, number. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. R-134A has a slightly lower pressure at evaporator temperatures (30-40 degrees), but R-134a also has a much higher pressure at condenser temperatures (120-150 degrees). Also the new quick connect fittings for the high & low side. and recharged with mineral oil and 2.2 lbs R12. How dumb!I will jumper the aux fan and redo the test. Hope this helps. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. There is only a temperature switch on these cars as far as I recall, and it just switches on the aux fan. 42 (at best) w/ 134A in 2000 isuzu trooper. Theres no problem with using R134a in a home air conditioning system because it is a hydrofluorocarbon that doesnt cause environmental harm. Just because the radiator does not boil people assume that the cooling system is ok. The R134a compressor has a 1/8" step in on the high side port. 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.