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). I'm going to check the condensor is way clean too. Kommentare . Fitting a PF condensor is not rocket science, but it requires some planning. Even though their common major function is to cool the system, they have many differences. The system has been previously converted to R-134a. Usually, mechanics charge around $200 for conversion. The ARPA Zone/Open Membership Discussion Forums. BTW, I use a stick thermo in the vents and the laser on the condenser. Are r12 and r134 fittings different? 4 Stars & Up & Up; 3 Stars & Up & Up; 2 Stars & Up . R12 and R22 are both now banned by the EPA in the United States. The difference really shows up on the high side. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. By: james smith underoath; Comments: 0 . 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. 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. However, theyre still used in older plants, systems, and the automotive industry. I don't think it has any air dams or seals, I'll check to make sure. They examined the two configurations of capillary tubes i.e. R134a Refrigerant Recharge Kit with BPV31 Bullet Piercing Valve and R134a Quick Coupler, R134a/R-12/R-22 Freon Refrigerant Hose Can Tap Kit for A/C System - Easy to use. Instead of using R12, its preferable to use R134a because it is very easy to find in the market, its sold at an affordable price, and is environmentally friendly. I'm having the same concern. Get to the point where I can walk without crutches2. 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. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. Yes, this was a smokers car. When you add fluorescent tracer dye to with the refrigerant oil it helps to track down leaks that push oil out of the system. Carefully study the chart and compare the following: To a large extent, the choice is up to you. GWP is a measurement of Greenhouse Gases and their effect on Global Warming. 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. 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. It will work and there will be very little, in any difference in performance.As Chick stated, the difference is only the gas used in the sensor tube. You may have heard of a friend that did the job himself with borrowed equipment and 12 or 16 ounce cans of refrigerant. and recharged with mineral oil and 2.2 lbs R12. But as there's not a big difference, people say you can suffice with either. If liquid refrigerant were to exit the evaporator. The experimental values of C.O.P.H obtained with the R134a/ester charge were 20.2% It is made up of carbon, hydrogen, and fluorine. The adjusted tension of this spring is the determining factor in the opening and closing of the expansion valve. 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. Blows pretty hard on full. Most of all the differences gravitate to longevity, functionality, and safety. I had a 1991 BMW switched to 134a by just changing the low pressure charging valve, flushing and refilling with 134 (maybe with 10% . R134a has the chemical formula CF3CH2F and is known as tetrafluoroethane. The cure is to use the newer R134a compressors is sealing washers that are different thickness. 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. Be sure to test @ 1500 to 2000 engine rpm, and record the ambient temp as well. If you you dont have the free time to play then you are better off to pay a technician. (On firewall where A/C lines go into cab.) 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 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. Flush with a garden hose - do not use a high pressure washer - you can bend the fins flat & damage the condensor.B. B. RULES for AOP - Owner Assistance and Contractors, Energy Efficiency and Building Performance Discussion NEW, Carnak Zone/Locked Areas - For Professional Member Only, How To Become a Pro and Rules For Pro Members, Pro Forum: Refrigerants and EPA regulations **NEW, Pro Forum: Residential Refrigeration and Appliances **NEW, Pro Forum: Equipment Recalls and Bulletins **NEW, Pro's Forum: Building Science Discussions, Educational Forums - Open for all in the industry, Welcome to HVAC-Talk's Educational Forums, How to Submit Links, Articles and Quiz Questions, Frequently Asked Questions About Submissions, Physics, Thermodynamics, Fluid Flow and Combustion, Educational, Training & Reference Information, Manufacturer's Technical Information Links, Electrical Theory, Circuits and Electronics, HVACR Equipment, Components & Accessories, Accessories Humidifiers, Air Cleaners, HRUs, Fans, Filters, etc. On the other hand, R12 has a global warming potential of 10,910. The mechanical fan & clutch should be checked as well. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. I used a full can of evap cleaner. Swapping the components isnt a herculean task, but recharging the AC is a challenge. R134a and R12 are both refrigerants used in vehicle air conditioning systems. Answer: OK, I'll bite. I dont know why the cost difference between compressors is so huge, though. For instance at 25 F the pressure of R-12 is 24.6 PSI and the pressure of R-134a is 22.1 PSI. Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. 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. 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 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. 10,000BTU conduction heating? -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. Most vehicles manufactured before 1993 have the R12 A/C system. Failure to abide by the EPA regulations can result in expensive fines for either you or your service technician. 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. R134a was selected as a replacement refrigerant for R12 because R12 contains chlorine and has a major effect to ozone layer depletion. "Howdy, Folks!" Is there a source of valves by, say, eaton number? 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. In most cases, the systems used have varied components, designs, and service ports. Took me a while to figure that one out, and how to say that. 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. It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. R134a is called tetrafluoroethane (HFC). And I lied about the compressor switches on this car - there are 2 switches on the drier - a temp and a pressure switch. 2) Frost on the Vents. 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. When I compare parts, 93 uses one part number and 94 has a different part number. 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. Welcome to rxmechanic.com. Generally this works well for the whole system. Vent temperatures slowly go down to around 50F with hi speed driving. By after changing just about everything, he got what was termed, satisfactory cooling. ambulance tailgate conversion Heres R12 vs. R134a pressure chart. Generally, the new amount is 75-85% of the quantity advised by the manufacturer. 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. This allows the refrigerant in the condenser to be void of oil particles. The oil used in R12 systems is not compatible with R134a refrigerant. They have no moving parts. This is because R134a. Condensers designed to release greater amounts of heat help to expel the greater amount of heat which R134a removes from the cars interior. I'm just trying to help you avoid headaches in the long run. First, differences in physical properties: 1, insoluble R12 compressor oil is used (to reduce the lubricant) 2, dissolved sealing materials are used (resulting in refrigerant leakage) 3, easy to damp (so easy to internal . It won't be optimal, though. Just had knee surgery yesterday, so I"M not exactly hopping around too well. The common problem when converting from R12 to R134a is lack of knowledge or equipment. But, what is considered a good temperature differential across the condensor? But as there's not a big difference, people say you can suffice with either. I cleaned the evap as best I could, if that is what you are getting at. 42 (at best) w/ 134A in 2000 isuzu trooper. You do not need to replace the expansion valve in most cases. SO here's my question. evarporator, expansion valve plus flushing out the full system and replacing all the o rings. After the optimum refrigerant charge is determined the car should be test driven to check for performance of the system. Its chemical symbol is CH2FCF3. Is there a graph? You may need to adjust the valve in a bit to get desired superheat. Thus, when the system is running, condensing the CO2 is not a problem. -------------------------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. 4) Repeat step 2, making sure it will fit. Look at where the lines will end up. I'll put the relay on for that. R12, on the other hand, is called chlorofluorocarbon (CFC). The bad thing is I don't know what to do 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. Is there a difference in the expansion valve for R12 as opposed to R-134a? About four or five years ago, I guy with an MB came here with the same problem, that tread was over six pages long. This would become an expensive investment for a repair or service station to have unique dedicated equipment for every type of alternative refrigerant. 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. If you have a York, and it is equipped with service valves, you can check & adjust the oil level without discharging the system. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. The aux fan seems to be working fine - it switches on occassionally. we convert older systems where i work all the time and they work fine. Jun 19, 2007. Unfortunately, the R12 refrigerant doesnt always blow cold air. difference between r12 and r134a expansion valvewarning signs for a deteriorating patient with covid 19 infection 2022.07.03 18:36 18:36 But I don't want to waste your time. Safety: R134a is safe to use as its non-flammable and cant explode. This refers to BTU's (heat) moved per pound of refrigerant moved. I have the original (R12) style expansion valve in the Maverick AC system. Besides, you have a greaseisel. Your average garage that works on a/c on the side probably would not have this. Figure 2 shows the different phases and pressures the refrigerant . If not, you just don't know unless a test is performed. 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. Is it exponential, squared? It didn't seem too dirty though - I don't think it is the problem, but I could be wrong. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. In 1994 they switched from R-12 to R-134a. When the temperature is reduced to-7C or below, the plants ability to cool the airdrops significantly. Use strips of foam to couple the two heat exchangers if necessary.B. Can I just use an adapter and save $200? So that indicates it is cooling well there doesn't it? Replace the drier with a drier that has a desiccant that is R134a compatible, use new R134a o-rings. 3) A TXV optimized for 134a will be ok with R12. Stopleak is also risky. The expansion valve(Tx) is in the car at the inlet line to the evaporator with compressors you best get advice from an ac specialist shop as the differences could be the gas that it pumps some systems use R12 and others use R134a or later gas yes R1234yf Freon gas can be replaced by R134a; the newer systems were designed with this in mind so no, there will be no damage to the compressor but some time in . I'm not sure. This works when the R12 charge specification is listed in pounds. Besides, its technology has been tested and trusted. What is a good differential? -------------------------"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." You can use the R134a retrofit capacity chart for this purpose. 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. Replied by Rich928 on topic R12 or R134a. Stay home and grill your own steaks and stir your own martini. They would then make short "jumper hoses" to connect to the existing stock hoses, refit your old fan if there is a "pusher" fan, and recharge to specs. Please enter the name by which you would like to log-in and be known on this site. All pre-97 XJs use systems with the same basic operating principle, although the parts do change a bit. Gain access to our free AOP (Ask a Professional) Section to get real answers for your questions. This is a great space to write long text about your company and your services. Edited: Sat July 14, 2007 at 10:22 PM by fonebone. However, R134a is better than R12. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . sparkee said: Thanks for the Service Bulletin. The larger line at the expansion valve is the suction line. Super heats are so close, it should not be a major concern.-------------------------The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government. _____ 2012 E350 2006 Callaway SC560 . had writing on the side that said R134a. The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. Also the new quick connect fittings for the high & low side. 5. Any ideas from the info above? You'll want the expansion valve matched to whatever refrigerant you're using. R12, on the other hand, has an ozone depletion potential of 1, implying that it can damage the ozone layer. R134a is called tetrafluoroethane (HFC). Your decision could be made based on economics, environmental concerns, or both. R134a refrigerant is lighter than R12. These two refrigerants are the older types and are not used in newer refrigeration and air conditioning systems. CLUTCH CYCLING SWITCH. Or is there always room for improvement, the more the merrier. What effect would it have on performance, if any? A final difference is that most (though not all) R-1234yf cars will have a Suction Line Heat Exchanger. -------------------------"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." You will be fine with a 134a-compatible TXV running R12. Still, I have some simple green, so may as well give it a go. 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. ThanksPaul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. Its chemical symbol is CCl2F2. Therefore, the higher the factor of the chemical (compound), the greater its effect on global warming. Energy usage: R134a is less efficient in cooling compared to R12. 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. 5. Some 1993 and older R12 systems aren't as 'compatible' as you'd think to switch over. There are R134a specific valves that operate at a slightly different pressure, but not for any "old" automotive application that I'm aware of. 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. In a car ac, using this type of freon 20 years ago was difficult. Participate in over 40 different forums and search/browse from nearly 3 million posts. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. 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. Until 1995, most cars with air conditioning used R-12 Freon refrigerant which has shown to have an environmental impact. Therefore, its most suitable for both commercial and domestic environments. The pressure at low temperatures is nearly the same between 12 and 134a. Is that reasonable?Vent airflow is good, I think. R-12 to R-134a Conversion. 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. As an example, let's say the R12 charge specification is listed at 2 lbs. R12, on the other hand, is called chlorofluorocarbon (CFC). 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. 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. CONCLUSIONS The differences in the theoretical C.O.P.H calculated for R12 and R134a are consistent with values quoted in the literature. I just got some hi/lo side gauges so I'm going to take readings, if they are needed. Its chemical symbol is CCl2F2. As for R134a and R1234yf, theres no room for conversion. An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback. Very nice! R-134a is widely believed to be the most acceptable R12 substitute. Rules governing changing from the former to the latter differ between countries. In cases such as this, the required capacity value of the expansion valve with R134a is reduced by 30% (correction factor 1.42). I have one can left, so maybe a plan can be made. . This is 11F off the FSM performance graph - vent should be around 50F. If you have 10 ounces of oil in the system, that is contributing to the poor performance as well. By using a black light the dye will glow in areas where oil leaks are visible. . It is made up of carbon, hydrogen, and fluorine. 3 ounces? Edited: Tue July 17, 2007 at 3:25 AM by bohica2xo, I believe there is only one switch - the refrigerant switch. You can use this space to go into a little more detail about your company. The catalytic converter is an essential component of your car's emission system that helps save the environment from harmful emissions. You can spend long evenings reading about the differences between the two refrigerants. 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. When the sensor detects the refrigerant leak the sniffers lights glow and the sniffer makes a noise. Below are the major differences between R134a and R12: The chemical composition of R12 and R134a differ. The current expansion valve is FF - 1/4 - C. Is it neccesary to replace this valve? At 2000rpm, windows open, highest fan, hi pressure stabilized at 225 psi, low 25psi.Ambient 81F, vent 61F. A comparison between R12 vs. R134a temperature will show that R12 has a higher temperature than R134a. Also, they are mostly used in refrigeration and automotive air conditioning systems. Are you sure you have an R4? R134a refrigerant fittings are different size. Hope this helps. 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. $21 . ). A/C receiver difference between R12 and R134a? I put one in my old daily driver '79 Chevy tank (r-12), and it really made a difference. What is needed? Related products. 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. Thomas Jefferson, Thanks,OK, I'm starting to feel a little better about it. Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). The condenser water inlet temperature and flow rate are controlled with the use of a . Inhalation of vapor: Inhaling a large amount of R134a vapor can lead to drowsiness, temporary nervous system depression, and lethargy. This is not to say that one of these small retro-fit kits cant be used, however to be used wisely. A. Pressure/temperature plot of R134a vs. R12 is shown in figure 1. Hopefully after you have read this entire page you will have enough information to determine which type of refrigerant is best for you. 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. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. The larger fitting goes on the discharge port and the smaller fitting goes on the suction line or compressor inlet / suction port. The best replacement for R134a is R1234yf, while R12 refrigerant replacement was R134a. Is there a difference between a R134a expansion valve and an R12 TXV? 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. Flushed, vacuumed etc. Right now you know you have a bit too much, but with a CR4P compressor this is an insurance policy. That is a good thing. It is a haloalkane and hydrofluorocarbon (HFC) refrigerant that has thermodynamic properties, potential global warming for one hundred years, and insignificant ozone depletion. difference between r12 and r134a expansion valve. I know this is bad, etc, and deposits on the metal can act as insulators. The cost of recharging the air conditioner is between $150 to $500. I don't recall all the details, but starts off with the largest parallel flow condenser and improved fans. Make sure to get the R12 EXP valve if that is the way you go. R12 is CFC: Even though R12 is one of the most commonly used refrigerants, it is CFC. Hence, the effect of R12 on global warming is up to 10,000 times higher than carbon dioxide. video clubhouse baseball; nick fairley draft profile; ben davis work pants
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