Rxmechanic.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for website owners to earn advertising fees by advertising and linking to Amazon.com. Large temperature difference between expansion valve inlet and outlet oReplace expansion valve Air . Since the hose is the stock hose, you cannot tell what refrigerant is inside. I'm doing one thing at a time so I know what the cause was. The oil used in R12 systems is not compatible with R134a refrigerant. What is a good differential? 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. _____ 2012 E350 2006 Callaway SC560 . 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. We ALWAYS want to know the pressure readings! However, it was found to be a very bad gas for the environment. If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? Don't like the sound of custom parallel condensor. There is more to check.The evaporator must be clean as well as the condensor - was this a smoker's car?You should check the water control valve for the heater core. 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. I've straightened the fans I can and sprayed simple green on it, let it soak then hosed it down well. The global warming potential of R134a is 1430. Ask Our Pros-Owner Assistance - NO DIY advice will be given. There is only a temperature switch on these cars as far as I recall, and it just switches on the aux fan. An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback. AC R12 to R134A Conversion | MR2 Owners Club Forum 4.R404A R134a increased mass transfer resistance to reduce the transmission chamber heat coefficient, while R507 heat transfer coefficient is higher than R404A. Crap! Look deep into the fins. Lets take you through the advantages, disadvantages, and differences of these two refrigerants a detailed comparison including R12 vs R134a performance. How is the vent airflow?I would jumper the aux fan & check the performance. The experimental values of C.O.P.H obtained with the R134a/ester charge were 20.2% Flushed, vacuumed etc. For R12, its mineral oil. in /nfs/c05/h04/mnt/113983/domains/toragrafix.com/html/wp-content . Talk about what services you provide. 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. difference between r12 and r134a expansion valve . That is a good thing. Bookmarks: Digg; del . R12 is highly destructive to the earths ozone layer. Since 2010, all home AC systems manufactured use a refrigerant like R134a that has zero ozone depletion potential (ODP). However, theyre still used in older plants, systems, and the automotive industry. Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. You may need to adjust the valve in a bit to get desired superheat. -------------------------"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." 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. R12 Expansion Valve = 201 830 06 84 R134A Expansion Valve = 201 830 04 84 Is there a difference after all? It didn't seem too dirty though - I don't think it is the problem, but I could be wrong. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. With the A/c off hi and lo were both at 105psi. PDF Experimental analysis of Thermostatic expansion valve, Constant PDF COMPARISON OF Rl34a AND R12 REFRIGERANTS IN A VAPOUR - AIVC 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 Operating Pressure/Temperature Differences The pressure/temperature curves for R-1234yf and R-134a are very similar. Recharge the compressor with a/c ester oil and a tracer dye. It is possible I have 10 ounces (250 ml) in the system. The adjusted tension of this spring is the determining factor in the opening and closing of the expansion valve. 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? That switch should close @ 52c. 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. A lower GWP alternative to R-134a had to be found and thus we have the new 1234yf. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. R134a requires the use of synthetic oil! 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. R12 contains a chemical called chlorine that destroys the ozone layer, thereby causing potential environmental risk. Trinary Pressure Switch quantity. You can buy bulk hose, and the proper fittings, then have them crimped off the vehicle.Be sure that no air bypasses the new condensor on the way to the radiator. The common problem when converting from R12 to R134a is lack of knowledge or equipment. The newer valves and switches will work with both refrigerants. I'm going to check the condensor is way clean too. Plus, not releasing the chemical into the air is morally justifiable. Refrigerators generally utilize R22, R32, or 410A-based coolants as their cooling agent. Paul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. If the system was upgraded by a professional it should have an upgrade sticker. Sense ells no existirem. R 134A is designed for the high demands of an automobile AC and cannot be used on refrigerators due to pressure differences. 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. R12 is otherwise called dichlorodifluoromethane is a colorless gas (chlorofluorocarbon halomethane (CPC) that is used as an aerosol spray propellant and a refrigerant, and is soluble in organic solvents. Recovery & flushing is the only way out of an oil overcharge in your vehicle.B. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores. Its highest value is 1. 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. system of 0.33 TR and refrigerant used was R12. The only difference I can imagine would be the recharge connection. The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. Most of all the differences gravitate to longevity, functionality, and safety. They can be mounted quite easy,and there is a mounting kit that helps to hang it. look at the difference! You'll want the expansion valve matched to whatever refrigerant you're using. However, R12 refrigerants are still used as fire retardants in aircraft and submarines. ESP when a compressor has frozen. Any advice appreciated. I recommend replacing the expansion valve when you do the swap. CLUTCH CYCLING SWITCH. The Main change in the system is the expansion valve. R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. After the system has been tested out it should be checked for leaks. Only show this user. It is made up of carbon, hydrogen, and fluorine. Vent temperatures slowly go down to around 50F with hi speed driving. Yep, definately not a meat locker. 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. Welcome to rxmechanic.com. 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. Flush with a garden hose - do not use a high pressure washer - you can bend the fins flat & damage the condensor.B. It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. But I don't want to waste your time. The crossover point is approximately at 64F. The aux fan didn't switch on though and I didn't check the high side temperature. A Comparison Study of the Thermal Performance of R12 and R134a . You are indeed 20% out of the OEM spec for cooling. Thus, when the system is running, condensing the CO2 is not a problem. Accessories Pumps, Cooling Towers, Evap Condensers, etc, Components Valves, Motors, Condensers, Evaporators, etc, Duct Systems Design, Installation & Practice, Piping Systems Design, Installation & Practice, Control System Design, Installation & Practice, Pro's Forum: National Electrical Code (NEC), Pro's Forum: Calculations & Electrical Theory, Pro's Forum: Electrical Business & Marketing. Hopefully after you have read this entire page you will have enough information to determine which type of refrigerant is best for you. With R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. The good thing is that after you convert to R134 you can top off the system easily and cheaply. When the temperature is reduced to-7C or below, the plants ability to cool the airdrops significantly. Gnats & mosquitos will clog deep. 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. I don't have the FSM matrix handy for that 123.123, but a 123.133 shows a test rpm of 2,000 - and vent temps between 54f & 66f at 91f to 95f ambient. Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). July 3, 2022July 3, 2022. Is it exponential, squared? With the knowledge of the differences, youll be able to draw a comparison between R12 vs R134a efficiency. 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. Until 1995, most cars with air conditioning used R-12 Freon refrigerant which has shown to have an environmental impact. Heres R12 vs. R134a pressure chart. Effects of alternative refrigerants on the ejector dimensions for 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. This would become an expensive investment for a repair or service station to have unique dedicated equipment for every type of alternative refrigerant. So to keep things simple and to avoid controversy and politics we have R134a. #4. Related products. 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. A/C R12 to R134a Conversion Success | IH8MUD Forum Before we mentioned that you can add approximately 5-6 ounces of ester oil to the compressor. compressor, condenser, evaporator and expansion valve are specifically designed for use with R134a. How thermostatic expansion valves work | Danfoss It's actually a reaction with chlorine in the mineral oil that may have been absorbed and leftover from the old R-12. Components Coils, Heaters, Motors, etc. These two refrigerants are the older types and are not used in newer refrigeration and air conditioning systems. Low refrigerating effect per pound: In comparison to other refrigerants, the refrigerating effect of R12 per pound is low. In more serious, it could result in cardiac irregularities or death. We've updated our forums!Click here to visit the new forum, Year: 1991Make: Jaguar Model: XJ6Engine Size: 4.0. You can also check the Aux fan in your case. 2) Frost on the Vents. The best replacement for R134a is R1234yf, while R12 refrigerant replacement was R134a. The original CFC expansion valve used for R12 needs to be replaced with an HFC one for 134a to feed the evaporator correctly. Bookmarks: Digg; del . R134a is called tetrafluoroethane (HFC). Yes it will work with either Refrigerant! Its cylinders are colored white. The R134a compressor has a 1/8" step in on the high side port. R12, on the other hand, is called chlorofluorocarbon (CFC). 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. The condenser water inlet temperature and flow rate are controlled with the use of a . The pressure/temperature curves for R-1234yf and R-134a are very similar. R12 and R134 are of different chemistry. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. Its chemical symbol is CH2FCF3. Minor adjustments to the expansion valve and other controls may be necessary for some plans. This works when the R12 charge specification is listed in pounds. Instead, top off R12 with R134a refrigerant. And no, you cannot "drain' excess oil out. Thus, when the system is running, condensing the CO2 is not a problem. Answer: OK, I'll bite. Then again, there are two different expansion valves. Here are the basics for converting a system that does not have a charge of R12, its empty. We suggest dumping the old refrigerant oil in a clean container and inspect the oil for sludge or waxing (old oil that has gelled) and contamination (metal particles). 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. The substitute that we used for R-12 was the new HFC called R-134a. Spray it deep, and let it sit for a few minutes. 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. Can I use the one for the R-12? But as there's not a big difference, people say you can suffice with either. The pressure at low temperatures is nearly the same between 12 and 134a. How is 1234yf different from . It's best to determine on a case-by-case basis while monitoring system pressures and output air temperature. -------------------------"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." Just had knee surgery yesterday, so I"M not exactly hopping around too well. Skin contact: If the R134a (liquid) comes in contact with your skin, it could cause a burn. of refrigerant insulation tape. Not osmosis, but you know what I mean). $21 . Interestingly, theres one oil type that works perfectly with both types of refrigerants. All fans must work at 100% of the OEM rating. What effect would it have on performance, if any? Theres no problem with using R134a in a home air conditioning system because it is a hydrofluorocarbon that doesnt cause environmental harm. Also called the orifice tube. It is perhaps possible to locate a unit with a company that purchases close out or distressed merchandise. (You must log in or sign up to reply here. To prevent refrigerant loss you should consider replacing your old hose lines with barrier type hose. 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. Still, I have some simple green, so may as well give it a go. 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. 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 is simply too expensive for a 25+ year old A/C system. Nice to use new gadgets! Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. 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. A comparison between R12 vs. R134a temperature will show that R12 has a higher temperature than R134a. If you you dont have the free time to play then you are better off to pay a technician. R12 is used in several applications like low temperature, medium temperature, and high-temperature applications. A York oil capacity is listed as "6.5 to 9.6 ounces". 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. Even if the system leaks, repairing the leaks and recharging it with R-12 is usually the best repair alternative. Your old hoses of course will not fit. Very interesting! Be sure to test @ 1500 to 2000 engine rpm, and record the ambient temp as well. About four or five years ago, I guy with an MB came here with the same problem, that tread was over six pages long. Even though their common major function is to cool the system, they have many differences. AFAIK, there is no clutch on the engine fan on the 240D. Though I have seen em run as cold as 12 deg F. If the thermo switch is malfunctioning. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. The difference really shows up on the high side. Hmmmm. The larger line at the expansion valve is the suction line. 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. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. The compressors used by refrigeration plants to compress gas require oil to help lubricate its moving parts. Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. Consider using the newer valve, even with 134a stamped on the valve. I mean, really a lot. In sum, R12 has done more bad than good. 10,000BTU conduction heating? By noting the ambient temperature you can look up what the preferred high side pressure should be. 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. It won't be optimal, though. At this point it is time to make an appointment with the a/c shop. _____ 2012 E350 2006 Callaway SC560 . difference between r12 and r134a expansion valve 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. From memory, I put in at least 8 ounces of oil, probably around 10 ounces in there. 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. Mine was 61, so the system is not working as it is supposed to. What is the refrigerant property involved that has caused this? Table 1 summarizes the technical characteristics of three potential R134a alternatives. I don't want to be chasing ghosts. difference between r12 and r134a expansion valve difference between r12 and r134a expansion valve So, instead of using R12, other better options include R401b, R134a, R401a, etc. BTW, I use a stick thermo in the vents and the laser on the condenser. Automotive Replacement Expansion Valves & Parts; Industrial & Scientific; Customer Reviews. 5. We consider the the various types alternative refrigerants that are illegal or not approved to be in two sectors: non-flammables and flammables. 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. A/C Expansion Valve Replacement Cost. I'm curiousSo there is work to do, ie performance should be able to be improved. 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. We say generally because the vehicle manufacturer may have a formula already worked out for the R134a conversion process. In the automotive world, the replacement for R12 was R134a. difference between r12 and r134a expansion valve PDF Tecumseh Guidelines for Utilization of R134a hardly noticable. 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). difference between r12 and r134a expansion valvewarning signs for a deteriorating patient with covid 19 infection 2022.07.03 18:36 18:36 The difference between the two is about 10,000 btu/h. 4) Inconsistent Airflow. GWP is a measurement of Greenhouse Gases and their effect on Global Warming. Yes, this was a smokers car. Most importantly, the oil used in the plant must always be compatible with the refrigerant used. |. 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. 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. This is because R134a. If you have the work done, be sure you find a true "A/C" shop that can make up lines. The bad thing is I don't know what to do about it. He used thermostatic expansion valve and Capillary tube for analysis with R12. 30 deg is pretty coldSystems generally run between 40 and 43 deg. Rules governing changing from the former to the latter differ between countries. 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. They have no moving parts. difference between r12 and r134a expansion valve 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. Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. R404a is a zeotropic blend with a temp glide , because of the mixture of 2 or more refrigerants. When you add fluorescent tracer dye to with the refrigerant oil it helps to track down leaks that push oil out of the system. What is usually sniffed are all the connections in the system: hoses and compressor, condenser, drier, expansion valve and evaporator fittings. Questions About Becoming A Professional Member? 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. had writing on the side that said R134a. difference between r12 and r134a expansion valve You may be just fine on oil - it depends on what compressor you have & how much oil you put in.A T/C is short for Thermocouple. The cable is adjustable at the valve arm. It is a haloalkane and hydrofluorocarbon (HFC) refrigerant that has thermodynamic properties, potential global warming for one hundred years, and insignificant ozone depletion. Theres no doubt that R12 refrigerant is one of the first compounds manufactured for the air conditioning and refrigeration world, but it had to be banned. I have the original (R12) style expansion valve in the Maverick AC system.
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