difference between r12 and r134a expansion valve

The best oil that runs well with R134a is PAG oil or Polyalkylene Glycol. Hot coolant migrates up through the core by convection (is that the word? 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. 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. 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. Do I leave the orignal condensor in, etc?Thanks. The global warming potential of R134a is 1430. Once you have replaced the OEM condensor with a PF unit, you will need to make custom hoses to mate with your OEM system. It is also used in automotive car conditioning and the plastic industry. = R134a Charge Level. 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. maintain the A/C of older cars. 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. gital control scheme. 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. Paul:A 1983 240D should have a York compressor on an OEM system. 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. shown for the parallel flow, aluminum condenser that is listed. Usually, mechanics charge around $200 for conversion. In 1994 they switched from R-12 to R-134a. Big . This implies that the discharge pressure of the compressor should be moderate so it can produce the refrigerants condensation in the condenser at the atmospheric temperature. had writing on the side that said R134a. of refrigerant insulation tape. The aux fan didn't switch on though and I didn't check the high side temperature. Can I just use an adapter and save $200? In more serious, it could result in cardiac irregularities or death. Helical and Serpentine coils. 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. The reason is that the vehicles, for instance, manufactured currently configure the engine for R1234yf refrigerant, making no provision for replacement. If it splashes inside the eye, it could lead to a serious eye problem. The primary function of the design engineer is to make things difficult for the fabricator and impossible for the serviceman. In a comparison between R12 vs R134a vs R1234yf, R1234yf will pass as the best refrigerant. Electric fans do wear out. 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. 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. Only show this user. This is because R134a. The next piece of equipment to track down leaks is a leak sniffer. Nick, I hear you - there maybe nothing to do here. R134a systems operate at higher discharge-side pressures than R12, which can cause compressor seals to leak. Before we mentioned that you can add approximately 5-6 ounces of ester oil to the compressor. I think the way to go here is1. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. 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. 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. -------------------------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. -------------------------"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 you have a York, and it is equipped with service valves, you can check & adjust the oil level without discharging the system. The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. -------------------------"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." absorb by the evaporator to insure all liquid refrigerant entering the evaporator. Discussion in 'Technical' started by Jsarnold, May 25, 2012. Besides, R134a refrigerant was manufactured after R12 was banned to help reduce the harshness of the old chemical (R12) on the ozone layer. Shorting the plug for the refrigerant switch should run the fan when the compressor is on. El juny de 2017, el mateix grup va decidir crear un web deDoctor Who amb el mateix objectiu. You do not want to exceed the systems high side recommendations. 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. Where would I get some basic info on it, I know nothing about it. american sniper longest shot; how to adjust sunsetter awning arms; pastor jeremy roberts texas. 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. One thing at a time here, and slowly, the knee is not up to jumping around like I used to at the moment. With that said, I would source the TXV from another source such as NAPA just to avoid any problems. The #1 question asked by NEW MEMBERS. 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. Is that why expansion valves are specific to R12 or R134A? R134a has an ozone depletion potential of 0, implying that it has a slight effect on the ozone layer. The analysis focuses on Coefficient of Performance for . R134a requires the use of synthetic oil! 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. We, the Rxmechanic team, have presented a well-detailed comparison of R134a vs. R12. I don't want to be chasing ghosts. (You must log in or sign up to reply here. Just leave it alone for now. Put a relay on the compressor clutch to the aux fan (I like that idea - makes a lot of sense)How does that sound? It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. The original CFC expansion valve used for R12 needs to be replaced with an HFC one for 134a to feed the evaporator correctly. Therefore, the higher the factor of the chemical (compound), the greater its effect on global warming. 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. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. It cycles on off in med (or low for that matter)Gotta tell ya. look at the difference! The original rubber a/c hose lines in your car will leak out R12 through the hoses lining. Also, they are mostly used in refrigeration and automotive air conditioning systems. A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . I remember I had the wrong seals and it leaked some oil, so I put some more in.Bohica - I tested the pressures. Later model cars that come with 134A will have 134A only connectors. 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. 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. The AC usually does not work at all. 3) A/C Compressor Always On. So to keep things simple and to avoid controversy and politics we have R134a. R12, on the other hand, is called chlorofluorocarbon (CFC). Components Coils, Heaters, Motors, etc. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . A. Pressure/temperature plot of R134a vs. R12 is shown in figure 1. Reattach the hose lines using new R134a compatible o-rings, lightly lubricate with compressor oil. 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. R134a requires a different oil. 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. I could easily be over at least 2 - 3 ounces over on the oil. we convert older systems where i work all the time and they work fine. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. Mine was 61, so the system is not working as it is supposed to. It is made up of carbon, hydrogen, and fluorine. . Is there a difference between a R134a expansion valve and an R12 TXV? Depending on which circuit diagram fits your car (cough, no vin list exists) you have either one or two switches controlling the aux fan. The major reason for the replacement of R12 with R134a was to curb future greenhouse effects. how to get to disney springs from boardwalk / bb dakota plaid jacket canada / difference between r12 and r134a expansion valve. . We recently created this blog site to enable us to share our knowledge with other automotive mechanics and car owners. 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. Use strips of foam to couple the two heat exchangers if necessary.B. Hence, let us continue to fix it. 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. -The amount of R-134a needed will typically be 80-90% of the R-12 charge. For R12, its mineral oil. 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. Performance doesn't seem to have improved. You'll want the expansion valve matched to whatever refrigerant you're using. 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. They can be mounted quite easy,and there is a mounting kit that helps to hang it. With the knowledge of the differences, youll be able to draw a comparison between R12 vs R134a efficiency. 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. Therefore, the R12 refrigerant is illegal, and emitting it is illegal. The difference between R12 and R134a TEV (exp valves) is primarily the 'superheat'. To prevent refrigerant loss you should consider replacing your old hose lines with barrier type hose. 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. That would be the "black death" syndrome. What is the refrigerant property involved that has caused this? Edited: Sat July 14, 2007 at 10:22 PM by fonebone. The experimental values of C.O.P.H obtained with the R134a/ester charge were 20.2% It didn't seem too dirty though - I don't think it is the problem, but I could be wrong. The current expansion valve is FF - 1/4 - C. Is it neccesary to replace this valve? 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. This is 11F off the FSM performance graph - vent should be around 50F. There is a lot of differences between the R12 and the R134a fittings, you can't mistake them. of coiled cap tube on VCR system with R134a. If you have a perfectly operating system using R12 you do not have to drop what you are doing and convert to R134a. You may need to adjust the valve in a bit to get desired superheat. 1) Warm Air From Vents. Until 1995, most cars with air conditioning used R-12 Freon refrigerant which has shown to have an environmental impact. Mark Baker R-401b is the mixture by weight of 61% R22, 11% R-152a and 28% of R-124. Make sure visiually that no large gaps exist that would allow the air to bypass the condensor on the way to the radiator.B. Yep, definately not a meat locker. BTW, I use a stick thermo in the vents and the laser on the condenser. Is it exponential, squared? Sense ells no existirem. There are R134a specific valves that operate at a slightly different pressure, but not for any "old" automotive application that I'm aware of. Use a drop light in the engine bay, and check the air path from the front of the car at night. You should keep in mind that recharging your air conditioner improperly could result in more serious damage. Recovery & flushing is the only way out of an oil overcharge in your vehicle.B. So that indicates it is cooling well there doesn't it? Bookmarks: Digg; del . Its chemical symbol is CH2FCF3. R-12 expansion valves can be re-used, but will not be as efficient as R-134a specific ones because of the slightly different pressure specs of R-12 vs. R-134a. As per their results . 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. Using R134a requires that Polyolester (POE) lubricant must be used in the compressor. 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. 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. 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 oil used in R12 systems is not compatible with R134a refrigerant. 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. Welcome to rxmechanic.com. 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. 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. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. 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. AFAIK, there is no clutch on the engine fan on the 240D. The safe high side pressures are determined with a PT (pressures and temperatures) chart. 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. This is a great space to write long text about your company and your services. When the sensor detects the refrigerant leak the sniffers lights glow and the sniffer makes a noise. How is 1234yf different from . . The global warming potential measures the amount of heat trapped by any gas compared to the amount of heat trapped by the same amount of carbon dioxide. 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. The condenser water inlet temperature and flow rate are controlled with the use of a . However, it was found to be a very bad gas for the environment. It won't be optimal, though. Related products. Recomanem consultar les pgines web de Xarxa Catal per veure tota la nostra oferta. 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. R12, on the other hand, is called chlorofluorocarbon (CFC). Are you sure you have an R4? This kit comes complete with Expansion valve, o-ring kit, and 1ft. Use a strong surfactant like Simple Green or Zep Citrus, and soak the fins on the condensor. 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. Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. In the automotive world, the replacement for R12 was R134a. It runs between the condenser outlet, receiver/drier unit and expansion valve at the firewall. 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. difference between r12 and r134a expansion valve. 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). It is mixed with the freon for the most part, and does accumulate in all components in small amounts. How is the vent airflow?I would jumper the aux fan & check the performance. Inasmuch as R134a has a global warming potential thats over 1000 times more threatening than carbon dioxide, its better than R12. R-134a is widely believed to be the most acceptable R12 substitute. This is due to many facts: R134a refrigerant is about 10% less efficient in moving heat than R12! Hopefully after you have read this entire page you will have enough information to determine which type of refrigerant is best for you. You may have heard of a friend that did the job himself with borrowed equipment and 12 or 16 ounce cans of refrigerant. Have a look in the FAQ Section, and look for "Fan clutches & testing them". The crossover point is approximately at 64F. The car never overheats, if that has any import. The difference really shows up on the high side. You'll get marginally better performance out of the change as the expansion valve is matches the refrigerant characteristics. A good T/C, clamped to the line & insulated gives a repeatable measurement of the tube. and an evaporator core and expansion valve that are optimized for R134a . 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 Then I'll put the ball valve in on the coolant and test it and see what we have. Heres R12 vs. R134a pressure chart. The difference between R12 and r134a is the BTU carrying capability. 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. 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. You do not however need to replace all the o-rings or seals for a simple conversion, it is simply a logical thing to do when and if the time comes to work or replace certain components because of age issues. difference between r12 and r134a expansion valvewarning signs for a deteriorating patient with covid 19 infection 2022.07.03 18:36 18:36 1) Look Here at the available sizes of PF condensors.2) Go look at your vehicle's condensor & mounting. I recommend replacing the expansion valve when you do the swap. The higher the ambient temperature the higher the high side pressure. 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. R1234yf is more environmentally friendly and has a global warming potential of 4. R134a is the most widely accepted alternative automotive refrigerant used to replace R12. 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. Is there a source of valves by, say, eaton number? 5. Superheat you can consider to be the additional amount of heat. R12 was once used in many air conditioning units as a refrigerant or cooling agent. 4.3 out of 5 stars 491. If liquid refrigerant were to exit the evaporator. I had a 1991 BMW switched to 134a by just changing the low pressure charging valve, flushing and refilling with 134 (maybe with 10% . 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. I had to vaccum the system for 2 hours and recharge 4 oz of PAG oil plus 36 oz of 134A freon (3 cans). I mean, really a lot. I know this is bad, etc, and deposits on the metal can act as insulators. There are three different refrigerants officially sanctioned by the EPA for automotive usage: r-12, r-. That way I will have reduced the oil by about 1/3 (assuming the oil is mixed evenly through the system). The system will be checked for gross leaks while under vacuum. However, theyre still used in older plants, systems, and the automotive industry. Very nice! 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. Like say half a can or so recharge come springtime warm weather or something. #13. Flush with a garden hose - do not use a high pressure washer - you can bend the fins flat & damage the condensor.B. R12 and R134 are of different chemistry. Poc temps desprs van decidir unir els dos webs sota el nom de Xarxa Catal, el conjunt de pgines que oferirien de franc sries doblades i/o subtitulades en catal. Safety: R134a is safe to use as its non-flammable and cant explode. Trinary Pressure Switch $ 39.99. With R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. And no, you cannot "drain' excess oil out. Can I order a valve based on the original eaton number? The R134a compressor has a 1/8" step in on the high side port. I have the original (R12) style expansion valve in the Maverick AC system. R134a was selected as a replacement refrigerant for R12 because R12 contains chlorine and has a major effect to ozone layer depletion. The aux fan seems to be working fine - it switches on occassionally. . A Lot of the fins are bent, especially at the top. Gain access to our free AOP (Ask a Professional) Section to get real answers for your questions. It is a haloalkane and hydrofluorocarbon (HFC) refrigerant that has thermodynamic properties, potential global warming for one hundred years, and insignificant ozone depletion. This would become an expensive investment for a repair or service station to have unique dedicated equipment for every type of alternative refrigerant. GWP is a measurement of Greenhouse Gases and their effect on Global Warming. Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. 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. The only difference I can imagine would be the recharge connection. Thanks again. _____ 2012 E350 2006 Callaway SC560 . link to How to cut off a Catalytic Converter. This refers to BTU's (heat) moved per pound of refrigerant moved. is good, then I should be looking elsewhere? Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. And I lied about the compressor switches on this car - there are 2 switches on the drier - a temp and a pressure switch. Hence, the effect of R12 on global warming is up to 10,000 times higher than carbon dioxide. But R22 is almost equally damaging. With R134a you do not rely on the site glass. 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. Right now you know you have a bit too much, but with a CR4P compressor this is an insurance policy. If the system was upgraded by a professional it should have an upgrade sticker. Even with proper fan operation, missing seals & air dams can effect condensor effeciency. What is a T/C?4. 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. You are indeed 20% out of the OEM spec for cooling. The butylcellusolve or the citrus solvent will dissolve the carcass in a few minutes. How about evacing 1 pound of refrig from the system, and then putting 1 lb of pure R12 back in? 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? R12 is CFC: Even though R12 is one of the most commonly used refrigerants, it is CFC. Should I do the test again with the the aux fan jumpered? With tube & fin condensors in MVAC applications there is never "too much" airflow. Failure to abide by the EPA regulations can result in expensive fines for either you or your service technician. R12 contains a chemical called chlorine that destroys the ozone layer, thereby causing potential environmental risk. Concentration level: The R134a vapor dilutes the oxygen concentration in the air to a low level, thereby causing harm. 10,000BTU conduction heating? Debug the condensor (I am a computer nerd after all!)3. R134a is called tetrafluoroethane (HFC). Thanks so much Bohica - you've save me many more hours of fruitless speculation. R134a has the chemical formula CF3CH2F and is known as tetrafluoroethane. and feeds it through an expansion valve. This can be very very expensive. difference between r12 and r134a expansion valve. Temp switch works the aux fan. Compressor. The compressors used by refrigeration plants to compress gas require oil to help lubricate its moving parts. Plus, not releasing the chemical into the air is morally justifiable. Hope this helps. Generally, the new amount is 75-85% of the quantity advised by the manufacturer. difference between r12 and r134a expansion valve . The old compressor used R12 and the new unit will be R134a. It's helluva humid and hot here in north florida, and I drive around all day for my job. I've done the FSM test and with 81F ambient, the vent should be 50F. R134a is called tetrafluoroethane (HFC).

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