difference between r12 and r134a expansion valve

In most cases, the systems used have varied components, designs, and service ports. These cheap kits usually have a few cans of R134a (either 12 ounce or 16 ounce), maybe an extra can of refrigerant oil, a few generic R134a charge port adapters and maybe some o-rings. how to get to disney springs from boardwalk / bb dakota plaid jacket canada / difference between r12 and r134a expansion valve. I think the way to go here is1. It won't be optimal, though. . 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 aux fan didn't switch on though and I didn't check the high side temperature. The evap is hard to get at. After the system has been tested out it should be checked for leaks. When ever possible you should ask the technician to note the same information on your repair bill and keep a copy in your glove box for future reference. ThanksPaul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. 1.5 ounces - hmmm. There is a lot of differences between the R12 and the R134a fittings, you can't mistake them. However, take note that R134a refrigerants are manufactured specifically for automotive air conditioners. Plus, not releasing the chemical into the air is morally justifiable. From memory, I put in at least 8 ounces of oil, probably around 10 ounces in there. Statisicaly your friend was lucky. When the temperature is reduced to-7C or below, the plants ability to cool the airdrops significantly. 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. 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. Flushed, vacuumed etc. difference between r12 and r134a expansion valve. I had to vaccum the system for 2 hours and recharge 4 oz of PAG oil plus 36 oz of 134A freon (3 cans). The difference between the two is about 10,000 btu/h. 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. You can also check the Aux fan in your case. Its not that difficult but the procedures of evacuation, charging and testing should be done by a licensed a/c technician that is experienced with R134a and your particular car. R404a for freezing of product. Pound for pound R134a is a more efficient refrigerant than R12, however it runs at higher pressures in some aspects and therefore requires more effective condensing. Therefore, the higher the factor of the chemical (compound), the greater its effect on global warming. There are R134a specific valves that operate at a slightly different pressure, but not for any "old" automotive application that I'm aware of. R134a is the most widely accepted alternative automotive refrigerant used to replace R12. I'm curiousSo there is work to do, ie performance should be able to be improved. I don't believe it is but I had a service guy tell me it needs to be done. Besides, its technology has been tested and trusted. had writing on the side that said R134a. But, what is considered a good temperature differential across the condensor? Environmental Impact: When R134a escapes into the atmosphere, it contributes to global warming. 42 (at best) w/ 134A in 2000 isuzu trooper. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. Still, I have some simple green, so may as well give it a go. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . What effect would it have on performance, if any? With R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. The sticker typically has a place to note the amount of refrigerant used, the type of oil and amount of oil, the technicians sign off or name and the date of the conversion. R12 was once used in many air conditioning units as a refrigerant or cooling agent. R12 can move more heat than r134 so when it isn't very hot and the system isn't maxed out you wont be able to tell the difference but when its 110 out and the inside is 140 R12 will cool the cabin temp faster. In cases such as this, the required capacity value of the expansion valve with R134a is reduced by 30% (correction factor 1.42). Also, it can be used with all types of compressors. If the system was upgraded by a professional it should have an upgrade sticker. Bookmarks: Digg; del . Below are the major differences between R134a and R12: Chemistry The chemical composition of R12 and R134a differ. 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. difference between r12 and r134a expansion valve. R134a is called tetrafluoroethane (HFC). Welcome to rxmechanic.com. Use a strong surfactant like Simple Green or Zep Citrus, and soak the fins on the condensor. |. R12, on the other hand, has an ozone depletion potential of 1, implying that it can damage the ozone layer. The AC usually does not work at all. shown for the parallel flow, aluminum condenser that is listed. is good, then I should be looking elsewhere? bokoen1 hoi4 the great purge / meryl and maks dancing with the stars / difference between r12 and r134a expansion valve. Also the new quick connect fittings for the high & low side. The major reason for the replacement of R12 with R134a was to curb future greenhouse effects. It's best to determine on a case-by-case basis while monitoring system pressures and output air temperature. Maybe a jerky locker.I cleaned the condensor with the off the shelf ac cleaner stuff from Home Depot that I used on my home evaporator. 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. 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. They have no moving parts. Helical and Serpentine coils. GWP is a measurement of Greenhouse Gases and their effect on Global Warming. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. I dont know why the cost difference between compressors is so huge, though. They plug all the time. Edited: Sat July 14, 2007 at 10:22 PM by fonebone. 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. The good thing is that after you convert to R134 you can top off the system easily and cheaply. Then again, there are two different expansion valves. You should keep in mind that recharging your air conditioner improperly could result in more serious damage. Replace the drier with a drier that has a desiccant that is R134a compatible, use new R134a o-rings. I remember I had the wrong seals and it leaked some oil, so I put some more in.Bohica - I tested the pressures. How dumb!I will jumper the aux fan and redo the test. A/C receiver difference between R12 and R134a? Inasmuch as R134a has a global warming potential thats over 1000 times more threatening than carbon dioxide, its better than R12. It's not just the poor performance - the cooling just stops working after a while. Moreso, it had been banned. difference between r12 and r134a expansion valve why is miles raney not on homestead rescue June 21, 2022. manila mayor candidates 2022 The R134a compressor has a 1/8" step in on the high side port. 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. I mean, really a lot. The whole trick is to sit there in those steam boxes and not perspire, it's vulgar to perspire when driving on public roads.If you want esteem, drive an MB, if you want comfort with 60*F interiors in a 125*F environment, get a Caddy. "Jerky Locker" LMAO I am using that one in the future!Florida = BUGS! Yes, this was a smokers car. 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. Usually, mechanics charge around $200 for conversion. Table 1 summarizes the technical characteristics of three potential R134a alternatives. difference between r12 and r134a expansion valve. Differences between R-12 and R-134a systems: 1. Safe but sorry! For example, if your system originally had 36 ounces of R12 then you multiply that by .80 and you have 29 ounce of R134a. Only show this user. By using a qualified a/c shop with the proper equipment you odds are in your favor of having the job done correctly the first time. A/C Expansion Valve Replacement Cost. Inhalation of vapor: Inhaling a large amount of R134a vapor can lead to drowsiness, temporary nervous system depression, and lethargy. #19. B. However, it was found to be a very bad gas for the environment. With R12 you use to check to see if the site glass was full, if it had bubbles it meant you had a low charge. 2001-2023 Griffiths Technical Inc. All Rights Reserved. AFAIK, there is no clutch on the engine fan on the 240D. . R12 is heavier than R134a and has smaller molecules. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . The global warming potential of R134a is 1430. Then I'll put the ball valve in on the coolant and test it and see what we have. This works when the R12 charge specification is listed in pounds. The experimental values of C.O.P.H obtained with the R134a/ester charge were 20.2% Lets take you through the advantages, disadvantages, and differences of these two refrigerants a detailed comparison including R12 vs R134a performance. A final difference is that most (though not all) R-1234yf cars will have a Suction Line Heat Exchanger. I have a laser temp reader, and it says the temps going into the condensor are up to 160F - coming out it is always around 110 or so. It is also used in automotive car conditioning and the plastic industry. We sometimes use a relay switched from the compressor clutch to run fans. Temp switch works the aux fan. Unfortunately, the R12 refrigerant doesnt always blow cold air. In more serious, it could result in cardiac irregularities or death. BTW, I use a stick thermo in the vents and the laser on the condenser. In practice this means that the car can overheat and the aux fan will stay off! 4 Stars & Up & Up; 3 Stars & Up & Up; 2 Stars & Up . and feeds it through an expansion valve. 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. What is needed? Thus, when the system is running, condensing the CO2 is not a problem. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. 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. ing the expansion valve, a maximum opening superheat of 7F, and a standard factory air test superheat setting. 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. It is usually sold under the brand name, Freon 12. -------------------------"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." 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 pressure at low temperatures is nearly the same between 12 and 134a. Performance doesn't seem to have improved. If you have the work done, be sure you find a true "A/C" shop that can make up lines. At 40, it is 35psi, which is a difference of 8.9psi. 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. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. . I am ordering new parts, and planning to convert my system to R-134a. And, unfortunately a small high side pressure gauge on a short hose. Comparatively, larger R134a molecules should take more space, and a smaller amount might be required. A Lot of the fins are bent, especially at the top. Next I'll jumper the aux fan. If the charge is low the compressor will cycle on/off in the max AC position. It won't be optimal, though. You do not want to exceed the systems high side recommendations. in /nfs/c05/h04/mnt/113983/domains/toragrafix.com/html/wp-content . On this website we are addressing only R134a and not other suggested drop in replacements. R12 is highly destructive to the earths ozone layer. About four or five years ago, I guy with an MB came here with the same problem, that tread was over six pages long. Thus, when the system is running, condensing the CO2 is not a problem. 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. They examined the two configurations of capillary tubes i.e. ambulance tailgate conversion Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). Is there a difference in the expansion valve for R12 as opposed to R-134a? 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. Its chemical symbol is CH2FCF3. A comparison between R12 vs. R134a temperature will show that R12 has a higher temperature than R134a. 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. However, the supply houses don't indicate a difference. The primary function of the design engineer is to make things difficult for the fabricator and impossible for the serviceman. Very nice! The adjusted tension of this spring is the determining factor in the opening and closing of the expansion valve. Therefore, the R12 refrigerant is illegal, and emitting it is illegal. Get to the point where I can walk without crutches2. Als nostres webs oferimOne Piece,Doctor Who,Torchwood, El Detectiu ConaniSlam Dunkdoblats en catal. 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. (On firewall where A/C lines go into cab.) If liquid refrigerant were to exit the evaporator. The problem with not being an expert is that you don't know what is important and what's not. This can be very very expensive. Gnats & mosquitos will clog deep. Most of all the differences gravitate to longevity, functionality, and safety. The difference really shows up on the high side. R134a has an ozone depletion potential of 0, implying that it has a slight effect on the ozone layer. Stay home and grill your own steaks and stir your own martini. As an example, let's say the R12 charge specification is listed at 2 lbs. R12 is simply too expensive for a 25+ year old A/C system. What was the ambient when you took that reading?Jumpering the aux fan is a common thing here in the desert. 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. I found that in the..Maxposition on the control it will have the compressor running all the time. Gain access to our free AOP (Ask a Professional) Section to get real answers for your questions. That is for the compressor, drier, expansion valve and condenser. The pressure at low temperatures is nearly the same between 12 and 134a. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. In sum, R12 has done more bad than good. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. Rules governing changing from the former to the latter differ between countries. I'm just trying to help you avoid headaches in the long run. Its chemical symbol is CCl2F2. Minor adjustments to the expansion valve and other controls may be necessary for some plans. Mine was 61, so the system is not working as it is supposed to. Is there a source of valves by, say, eaton number? The value of carbon dioxide is 1. system of 0.33 TR and refrigerant used was R12. When you add fluorescent tracer dye to with the refrigerant oil it helps to track down leaks that push oil out of the system. Spray it deep, and let it sit for a few minutes. Before we mentioned that you can add approximately 5-6 ounces of ester oil to the compressor. CR4P). Different correction factors are applied to other refrigerants. The original CFC expansion valve used for R12 needs to be replaced with an HFC one for 134a to feed the evaporator correctly. Yes it will work with either Refrigerant! Well, I'm not sure it is 'fine' - it doesn't cool very well in 95F weather. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. However, R134a is better than R12. Yep, definately not a meat locker. Sense ells no existirem. 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.