Trinary Pressure Switch quantity. If you have a York, and it is equipped with service valves, you can check & adjust the oil level without discharging the system. I've done the FSM test and with 81F ambient, the vent should be 50F. 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. 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. The system will be checked for gross leaks while under vacuum. It's not just the poor performance - the cooling just stops working after a while. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. Paul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. Stability: RR12 doesnt disintegrate even under extreme operating conditions. 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 is 1234yf different from . It is usually sold under the brand name, Freon 12. Thomas Jefferson, Thanks,OK, I'm starting to feel a little better about it. 2) Frost on the Vents. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. 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. Then when it is switched off for a few minutes and then back on, the air cools again. The first vehicle that used the R1234yf refrigerant was the 2013 Cadillac XTS. I dont know why the cost difference between compressors is so huge, though. of refrigerant insulation tape. With R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. If you have a perfectly operating system using R12 you do not have to drop what you are doing and convert to R134a. In the automotive world, the replacement for R12 was R134a. I bought a relay to put on it connected to the compressor clutch. Gnats & mosquitos will clog deep. After the optimum refrigerant charge is determined the car should be test driven to check for performance of the system. R12 contains a chemical called chlorine that destroys the ozone layer, thereby causing potential environmental risk. We, the Rxmechanic team, have presented a well-detailed comparison of R134a vs. R12. This is not to say that one of these small retro-fit kits cant be used, however to be used wisely. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyers guides, and car and tools comparisons. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. Ensure you contact a professional mechanic to do the work for you so you dont end up incurring more costs for yourself. R134a and R12 are among the most popular types of refrigerants. They examined the two configurations of capillary tubes i.e. If the system was upgraded by a professional it should have an upgrade sticker. UNDERSTANDING A/C Everything You Need To Know - Classic Auto Air 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. I don't think it has any air dams or seals, I'll check to make sure. and he synthesized R-134a in 1936, 5 years after R-12 was . Most vehicles manufactured before 1993 have the R12 A/C system. 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. Hopefully after you have read this entire page you will have enough information to determine which type of refrigerant is best for you. gital control scheme. The approval is very legal one, governed by the U.S. EPA. James10952001. $21 . We ALWAYS want to know the pressure readings! The ARPA Zone/Open Membership Discussion Forums. Thanks again. #4. Whether R134a performs as well as R12 in any given a/c system depends upon system components and the amount of R134a used. R12 was once used in many air conditioning units as a refrigerant or cooling agent. The current expansion valve is FF - 1/4 - C. Is it neccesary to replace this valve? 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. Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. Your decision could be made based on economics, environmental concerns, or both. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. Existing technology: R134a has been in use in the refrigeration industry for very many years, and theres so much information about the safe use of the product. Stopleak is also risky. Whenever its exposed to the environment, it changes to a gas. 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. R-12 to R-134a Conversion. Hence, let us continue to fix it. Then at least I'd know really where I am on it. You can also check the Aux fan in your case. difference between r12 and r134a expansion valve 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. In addition, R134a refrigerants are not only used in auto air conditioners, they can be used in freezers, aerosol cans, and refrigerators. Thus, when the system is running, condensing the CO2 is not a problem. 1.5 ounces - hmmm. Like say half a can or so recharge come springtime warm weather or something. There is a lot of differences between the R12 and the R134a fittings, you can't mistake them. In a car ac, using this type of freon 20 years ago was difficult. 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. evarporator, expansion valve plus flushing out the full system and replacing all the o rings. Minor adjustments to the expansion valve and other controls may be necessary for some plans. R404a for freezing of product. 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? Your old hoses of course will not fit. Bookmarks: Digg; del . If you still find it difficult to use R134a in a home AC system, you can check out a comparison of R12 vs R134a fittings to know the refrigerant that best fits the AC system. The system has been previously converted to R-134a. The difference between R12 and R134a TEV (exp valves) is primarily the 'superheat'. "Howdy, Folks!" And I lied about the compressor switches on this car - there are 2 switches on the drier - a temp and a pressure switch. They have no moving parts. R12 systems used mineral oil, but unfortunately mineral oil doesn't dissolve in R134a. The original expansion valves work very well with R134a. compressor, condenser, evaporator and expansion valve are specifically designed for use with R134a. As an example, let's say the R12 charge specification is listed at 2 lbs. Debug the condensor (I am a computer nerd after all!)3. R134a refrigerant is lighter than R12. This would become an expensive investment for a repair or service station to have unique dedicated equipment for every type of alternative refrigerant. An extra half ounce? Expansion Valve for R134a? | Team Chevelle |. 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. I know this is bad, etc, and deposits on the metal can act as insulators. Production of R12 ceased in 1996, although it can still be reclaimed, purified, and resold, and small cans of New Old Stock R12 are still widely available on eBay and Craigslist. I'll report back on the aux fan on performance next. There are three different refrigerants officially sanctioned by the EPA for automotive usage: r-12, r-. 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. Related products. Are you sure you have an R4? That way I will have reduced the oil by about 1/3 (assuming the oil is mixed evenly through the system). But as there's not a big difference, people say you can suffice with either. I'm not sure. I'm thinking I might have put too much oil in the system - everywhere i read had a different amount - the manufacturer of the compressor, the MB factory service manual, online forums. What is a good differential? The reason is that the vehicles, for instance, manufactured currently configure the engine for R1234yf refrigerant, making no provision for replacement. This may be the source of your oil confusion. Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. 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. Use a strong surfactant like Simple Green or Zep Citrus, and soak the fins on the condensor. Inasmuch as R134a has a global warming potential thats over 1000 times more threatening than carbon dioxide, its better than R12. Here are the basics for converting a system that does not have a charge of R12, its empty. To prevent refrigerant loss you should consider replacing your old hose lines with barrier type hose. On this website we are addressing only R134a and not other suggested drop in replacements. By noting the ambient temperature you can look up what the preferred high side pressure should be. I'm doing one thing at a time so I know what the cause was. The safe high side pressures are determined with a PT (pressures and temperatures) chart. This works when the R12 charge specification is listed in pounds. Some compressor manufacturers or OEMs suggest PAG type oil for R134a. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. This refers to BTU's (heat) moved per pound of refrigerant moved. 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. However, it was found to be a very bad gas for the environment. R-134a is widely believed to be the most acceptable R12 substitute. A/C R12 to R134a Conversion Success | IH8MUD Forum But R22 is almost equally damaging. If the system was upgraded by a professional it should have an upgrade sticker. Since 2010, all home AC systems manufactured use a refrigerant like R134a that has zero ozone depletion potential (ODP). And, unfortunately a small high side pressure gauge on a short hose. Use strips of foam to couple the two heat exchangers if necessary.B. PDF Tecumseh Guidelines for Utilization of R134a George Bray on Wed August 31, 2005 5:03 PM I believe the optimum supercool setting will vary slightly between an expansion valve for an R12, as compared to R134a, system. At this point it is time to make an appointment with the a/c shop. Below are the major differences between R134a and R12: The chemical composition of R12 and R134a differ. 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. -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a, Bohica, You say the drop in performance is not linear with too much oil. By: james smith underoath; Comments: 0 . Spray it deep, and let it sit for a few minutes. So I probably put the highest suggested amount in to be safe. BTW, I use a stick thermo in the vents and the laser on the condenser. R-12 - yellow R-134a - light blue R-22 - green R-402A - light brown (sand) R-402B - olive R-404A - orange R-407C - medium brown R-410A - rose R-507 - teal J Originally Posted by goldNSX. video clubhouse baseball; nick fairley draft profile; ben davis work pants However, you can convert R12 to R134a by yourself, save money and keep all the tools purchased. The substitute that we used for R-12 was the new HFC called R-134a. _____ 2012 E350 2006 Callaway SC560 . 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. Look at where the lines will end up. This can be very very expensive. In most cases, the systems used have varied components, designs, and service ports. Is there a graph? The AC usually does not work at all. Next I'll jumper the aux fan. The difference between the two is about 10,000 btu/h. Is there a difference between a R134a expansion valve and an R12 TXV? a 50f delta across the condensor is good, but I suspect that is an idle reading. R134a refrigerant is about 10% less efficient in moving heat than R12! The original CFC expansion valve used for R12 needs to be replaced with an HFC one for 134a to feed the evaporator correctly. 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. Talk about what services you provide. 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. Neuro spine Super Speciality Clinic - Above Apollo Pharmacy, Bangarpet Circle, Kolar - Bangarpet Road, Kolar Town. Generally the system will be initially charged with approximately 80% to 85% of the original amount of R12, using R134a. I think the way to go here is1. Its highest value is 1. Operating Pressure/Temperature Differences The pressure/temperature curves for R-1234yf and R-134a are very similar. R12, on the other hand, has an ozone depletion potential of 1, implying that it can damage the ozone layer. 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. Stay home and grill your own steaks and stir your own martini. I'm going to check the condensor is way clean too. 3 ounces? For those of you who are considering what the cost is for R12 you can think of it this way: Dont go out to dinner this weekend. The newer valves and switches will work with both refrigerants. Discussion in 'Technical' started by Jsarnold, May 25, 2012. look at the difference! "Jerky Locker" LMAO I am using that one in the future!Florida = BUGS! The MB chart shows 360 psi with R12 in some conditions. I could easily be over at least 2 - 3 ounces over on the oil. Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. Recharge the compressor with a/c ester oil and a tracer dye. R134a requires the use of synthetic oil! R134a is called tetrafluoroethane (HFC). Its chemical symbol is CCl2F2. 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. Shorting the plug for the refrigerant switch should run the fan when the compressor is on. Catalog E-1, Thermostatic & Automatic Expansion Valves / Page 1 Table of Contents . Best for varieties of operating conditions: Its boiling point is -21.6 Celsius. It won't be optimal, though. 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 . R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. The higher the ambient temperature the higher the high side pressure. Then again, there are two different expansion valves. What is a T/C?4. 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. After the system has been tested out it should be checked for leaks. The car never overheats, if that has any import. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores. Most importantly, the oil used in the plant must always be compatible with the refrigerant used. PaulJerky King -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. . On the other hand, R12 has a global warming potential of 10,910. What is usually sniffed are all the connections in the system: hoses and compressor, condenser, drier, expansion valve and evaporator fittings. Yep, definately not a meat locker. Fitting a PF condensor is not rocket science, but it requires some planning. Please enter a password for your user account. 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. Figure 2 shows the different phases and pressures the refrigerant . _____ 2012 E350 2006 Callaway SC560 . It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. Its chemical symbol is CCl2F2. Disconnect the two hose lines to the compressor, protect the ends from getting dirty. Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). Ask Our Pros-Owner Assistance - NO DIY advice will be given. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . 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. I've straightened the fans I can and sprayed simple green on it, let it soak then hosed it down well. Trinary Pressure Switch $ 39.99. Any suggestions, or do you need to know the hi/lo readings? difference between r12 and r134a expansion valve. With tube & fin condensors in MVAC applications there is never "too much" airflow. Environmental Impact: When R134a escapes into the atmosphere, it contributes to global warming. Further production of R12 was banned in some developed countries by the Montreal Protocol because of its harsh effect on the ozone layer. Or is there always room for improvement, the more the merrier. Flushed, vacuumed etc. -------------------------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! I remember I had the wrong seals and it leaked some oil, so I put some more in.Bohica - I tested the pressures. The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. Thanks for the input. Please enter a valid email address for yourself. We recently created this blog site to enable us to share our knowledge with other automotive mechanics and car owners. The expansion valve is designed so that the temperature of the refrigerant at the evaporator outlet must have 8 to 12F (4 to 7C) of superheat before more refrigerant is allowed to enter the evaporator. The cable is adjustable at the valve arm. Hence, the effect of R12 on global warming is up to 10,000 times higher than carbon dioxide. Be sure to test @ 1500 to 2000 engine rpm, and record the ambient temp as well. I am ordering new parts, and planning to convert my system to R-134a. 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. Superheat you can consider to be the additional amount of heat. Crap! Hot coolant migrates up through the core by convection (is that the word? There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. Below are the major differences between R134a and R12: Chemistry The chemical composition of R12 and R134a differ. For instance at 25 F the pressure of R-12 is 24.6 PSI and the pressure of R-134a is 22.1 PSI. The pressure/temperature curves for R-1234yf and R-134a are very similar. R134a refrigerant fittings are different size. Als nostres webs oferimOne Piece,Doctor Who,Torchwood, El Detectiu ConaniSlam Dunkdoblats en catal. Are r12 and r134 fittings different? Edited: Sat July 14, 2007 at 10:22 PM by fonebone. Thread starter goldNSX; Start date 1 August 2009; Tagged . This kit comes complete with Expansion valve, o-ring kit, and 1ft. Before we mentioned that you can add approximately 5-6 ounces of ester oil to the compressor. 2022 nba 2k22 starting a fashion label signing the designer, a difference between r12 and r134a expansion valve, 2020 white paper of the church of pentecost, Chime Mobile Check Deposit Funds Availability, Why Does James Kill Donald In The Vanishing, nba 2k22 starting a fashion label signing the designer. Looks like a couple of things happening here1) 80's vintage Eurocars were not "meat lockers". 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. -------------------------"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." 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. You will be fine with a 134a-compatible TXV running R12. I mean, really a lot. 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. Carefully study the chart and compare the following: To a large extent, the choice is up to you. Additionally, R134a was introduced as a replacement for R22 and R12 in high and medium-temperature refrigeration systems like domestic and commercial chillers. Refrigerators generally utilize R22, R32, or 410A-based coolants as their cooling agent. 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. Agram a retevis rt22 password i bastrop county district clerk records el material que oferim als nostres webs. I don't know where it is getting the switch off command, or why the vent temp drops steadily. Also, if you want to know what happens if you put R134a in an R12 system, you should first confirm if the R12 system can be replaced or if the refrigerants can be mixed. The adjusted tension of this spring is the determining factor in the opening and closing of the expansion valve. Unfortunately, the oil only mixes with the refrigerant as a liquid. Miscibility with oil: R12 can be mixed with the compressor oil no matter the operating condition. 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 Main change in the system is the expansion valve. This is a great space to write long text about your company and your services. I had a 1991 BMW switched to 134a by just changing the low pressure charging valve, flushing and refilling with 134 (maybe with 10% . Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge. You may have heard of a friend that did the job himself with borrowed equipment and 12 or 16 ounce cans of refrigerant. R12 and R22 are both now banned by the EPA in the United States. Sense ells no existirem. It's actually a reaction with chlorine in the mineral oil that may have been absorbed and leftover from the old R-12. This is due to many facts: R134a refrigerant is about 10% less efficient in moving heat than R12! Though I have seen em run as cold as 12 deg F. If the thermo switch is malfunctioning. Yes it will work with either Refrigerant! ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. From memory, I put in at least 8 ounces of oil, probably around 10 ounces in there. CONCLUSIONS The differences in the theoretical C.O.P.H calculated for R12 and R134a are consistent with values quoted in the literature. It's helluva humid and hot here in north florida, and I drive around all day for my job. Bottom line, R134a simply doesn't cool as well as R12. 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. 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. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . Why wait for 200f on the engine coolant to start the fan? The global warming potential of R134a is 1430. 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). Moreso, it had been banned. The best oil that runs well with R134a is PAG oil or Polyalkylene Glycol. Lets take you through the advantages, disadvantages, and differences of these two refrigerants a detailed comparison including R12 vs R134a performance. system of 0.33 TR and refrigerant used was R12. Even though their common major function is to cool the system, they have many differences. Generally this works well for the whole system. Vent temperatures slowly go down to around 50F with hi speed driving. We chose to use 5-6 ounces of oil to be on the safe side: 3-4 ounces for the compressor, 1 oz of oil for the drier and another ounce of oil for system losses.
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