Are you sure you have an R4? difference between r12 and r134a expansion valve. If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. R12 and R134 are of different chemistry. Remove the old mineral oil from the compressor by turning it upside down, side to side, and turn the front hub on the clutch assembly. A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . Catalog E-1, Thermostatic & Automatic Expansion Valves / Page 1 Table of Contents . If not, you just don't know unless a test is performed. 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. The cable is adjustable at the valve arm. The ARPA Zone/Open Membership Discussion Forums. 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. -------------------------"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 difference between the two is about 10,000 btu/h. The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. The only material difference between automotive A/C and a window A/C unit or refrigerator is that in the home application, the components are all inside the same rectangular box, but in the automotive application, the components are distributed throughout the car. and he synthesized R-134a in 1936, 5 years after R-12 was . I cleaned the evap as best I could, if that is what you are getting at. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. Most vehicles manufactured before 1993 have the R12 A/C system. Until 1995, most cars with air conditioning used R-12 Freon refrigerant which has shown to have an environmental impact. VerticalScope Inc. All Rights Reserved. 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. and feeds it through an expansion valve. You do not need to replace every o-ring in the system, but if you happen to open a connection that has an o-ring you should replace the old o-ring with one that is compatible with R134a and lubricate the o-ring with ac oil. R12 and R22 are both now banned by the EPA in the United States. Can I use the one for the R-12? 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. 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. In more serious, it could result in cardiac irregularities or death. Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. Paul:It is never a waste of my time to chat with someone that understands the problem, and wants to fix it. 5. Next I'll jumper the aux fan. Bookmarks: Digg; del . Edited: Sat July 14, 2007 at 10:22 PM by fonebone. In a car ac, using this type of freon 20 years ago was difficult. . CLUTCH CYCLING SWITCH. 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 condenser water inlet temperature and flow rate are controlled with the use of a . Whether R134a performs as well as R12 in any given a/c system depends upon system components and the amount of R134a used. I used a full can of evap cleaner. . After the optimum refrigerant charge is determined the car should be test driven to check for performance of the system. Moreso, it had been banned. This can be very very expensive. 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. R1234yf. My turn to LOL - greasiesel! With R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. Automotive Replacement Expansion Valves & Parts; Industrial & Scientific; Customer Reviews. Yes, this was a smokers car. The original rubber a/c hose lines in your car will leak out R12 through the hoses lining. All pre-97 XJs use systems with the same basic operating principle, although the parts do change a bit. _____ 2012 E350 2006 Callaway SC560 . 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. Agram a retevis rt22 password i bastrop county district clerk records el material que oferim als nostres webs. I'm having the same concern. 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. Note that passwords are case-sensitive. As an example, let's say the R12 charge specification is listed at 2 lbs. However, if it is taken close to a fire flame or any electrical heating element, it disintegrates into toxic products. ESP when a compressor has frozen. Plus, not releasing the chemical into the air is morally justifiable. I don't believe it is but I had a service guy tell me it needs to be done. For instance at 25 F the pressure of R-12 is 24.6 PSI and the pressure of R-134a is 22.1 PSI. Even if the system leaks, repairing the leaks and recharging it with R-12 is usually the best repair alternative. R-134a can actually cool better than R-12 in a well designed R-134a system as it has better thermoconductive properties, but all the high pressure issues have to be addressed.But even when these cars were brand new, didn't cool worth a damned, recall almost dying in one in Las Vegas at the time, but a good way to lose weight with gallons of perspiration pouring out, just don't let that drip on the seats, that is inappropriate. gital control scheme. Lasers don't do well on vent temps, a stick thermometer is better in that application. I've straightened the fans I can and sprayed simple green on it, let it soak then hosed it down well. The approval is very legal one, governed by the U.S. EPA. 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. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. Jun 17, 2011. and recharged with mineral oil and 2.2 lbs R12. 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. Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. Carefully study the chart and compare the following: To a large extent, the choice is up to you. Ensure you contact a professional mechanic to do the work for you so you dont end up incurring more costs for yourself. Is there a difference between a R134a expansion valve and an R12 TXV? An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback. Yes, I don't trust the heater valve either. They should be able to keep you comfortable on a long trip, but don't expect vent frost in 3 minutes or lesss.2) Too much oil can reduce cooling capacity, and the effect is not linear. From memory, I put in at least 8 ounces of oil, probably around 10 ounces in there. 2001-2023 Griffiths Technical Inc. All Rights Reserved. So you could likely put off buying those new hoses just a bit longer if you wanted. If you find any of these conditions you will want to liquid flush (with dedicated AC flush solution) all the lines, condensers, evaporator (remove the expansion valve) before you proceed further. Stopleak is also risky. Why wait for 200f on the engine coolant to start the fan? 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. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. The only difference I can imagine would be the recharge connection. Best for varieties of operating conditions: Its boiling point is -21.6 Celsius. The system will be checked for gross leaks while under vacuum. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . R134a refrigerant fittings are different size. Inhalation of vapor: Inhaling a large amount of R134a vapor can lead to drowsiness, temporary nervous system depression, and lethargy. |. ing the expansion valve, a maximum opening superheat of 7F, and a standard factory air test superheat setting. Warning: "continue" targeting switch is equivalent to "break".Did you mean to use "continue 2"? R134a. How is 1234yf different from . The reason is that the vehicles, for instance, manufactured currently configure the engine for R1234yf refrigerant, making no provision for replacement. 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. Blows pretty hard on full. The adjusted tension of this spring is the determining factor in the opening and closing of the expansion valve. The ozone depletion potential of a chemical is a factor that shows the level of degradation itll cause to the ozone layer that surrounds and secures the earth from harmful radiation. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. R134a requires a different oil. 3) A TXV optimized for 134a will be ok with R12. Is there a difference in the expansion valve for R12 as opposed to R-134a? 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. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. Kommentare . The car never overheats, if that has any import. Before we mentioned that you can add approximately 5-6 ounces of ester oil to the compressor. 42 (at best) w/ 134A in 2000 isuzu trooper. To ensure the right charge, you must fill the new system with between 75 and 85% of the factory-set capacity for optimal cooling. Does it matter - assuming both are new & uncontaminated? The aux fan seems to be working fine - it switches on occassionally. a 50f delta across the condensor is good, but I suspect that is an idle reading. R12 is heavier than R134a and has smaller molecules. Not going to mess up your 'do, but you can feel it. If it splashes inside the eye, it could lead to a serious eye problem. There is only a temperature switch on these cars as far as I recall, and it just switches on the aux fan. Break out the new gauges and measure hi and lo at 1500rpm, and do the Merc FSM test to see how we're doing performance wise. They have no moving parts. 10,000BTU conduction heating? Right now you know you have a bit too much, but with a CR4P compressor this is an insurance policy. It is perhaps possible to locate a unit with a company that purchases close out or distressed merchandise. 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. With the knowledge of the differences, youll be able to draw a comparison between R12 vs R134a efficiency. 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. difference between r12 and r134a expansion valvewarning signs for a deteriorating patient with covid 19 infection 2022.07.03 18:36 18:36 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 dont know why the cost difference between compressors is so huge, though. Are r12 and r134 fittings different? 37 in 2005 tacoma, R134A. Please enter a valid email address for yourself. However, the supply houses don't indicate a difference. You do not want to exceed the systems high side recommendations. 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. Expansion Valve. 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. Reattach the hose lines using new R134a compatible o-rings, lightly lubricate with compressor oil. Paul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. "Jerky Locker" LMAO I am using that one in the future!Florida = BUGS! About four or five years ago, I guy with an MB came here with the same problem, that tread was over six pages long. Then when it is switched off for a few minutes and then back on, the air cools again. That switch should close @ 52c. This is a great space to write long text about your company and your services. 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. 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. R12 is used in several applications like low temperature, medium temperature, and high-temperature applications. Differences between R-12 and R-134a systems: 1. I don't know where it is getting the switch off command, or why the vent temp drops steadily. Is there a graph? Not osmosis, but you know what I mean). Then again, there are two different expansion valves. Very interesting! evarporator, expansion valve plus flushing out the full system and replacing all the o rings. 2) Frost on the Vents. We ALWAYS want to know the pressure readings! 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. 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. Hope this helps. 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. It does not "pool" to any degree in a large amount anywhere. AFAIK, there is no clutch on the engine fan on the 240D. Shorting the plug for the refrigerant switch should run the fan when the compressor is on. You can use the R134a retrofit capacity chart for this purpose. We mention using ester type refrigerant oil. Should I do the test again with the the aux fan jumpered? Consider using the newer valve, even with 134a stamped on the valve. Flushed, vacuumed etc. 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. 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. All fans must work at 100% of the OEM rating. 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. how to get to disney springs from boardwalk / bb dakota plaid jacket canada / difference between r12 and r134a expansion valve. The next piece of equipment to track down leaks is a leak sniffer. Generally the system will be initially charged with approximately 80% to 85% of the original amount of R12, using R134a. Its chemical symbol is CH2FCF3. With the A/c off hi and lo were both at 105psi. 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. Also, they are mostly used in refrigeration and automotive air conditioning systems. 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. Besides, its technology has been tested and trusted. How an A/C Expansion Valve Works. A final difference is that most (though not all) R-1234yf cars will have a Suction Line Heat Exchanger. It won't be optimal, though. Is the information not applicable to the old Pantera system? R1234yf is more environmentally friendly and has a global warming potential of 4. This chart has a column of ambient (outside) air temperatures on one side and a corresponding range of high side pressures on the other side. Replace the drier with a drier that has a desiccant that is R134a compatible, use new R134a o-rings. 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. The most common influences which effect the capability of R134a to perform well are the condenser, in some cases the the superheat setting of the expansion valve or the amount of R134a. The system has been previously converted to R-134a. SO here's my question. R12, on the other hand, has an ozone depletion potential of 1, implying that it can damage the ozone layer. But, what is considered a good temperature differential across the condensor? Ask Our Pros-Owner Assistance - NO DIY advice will be given. The problem with not being an expert is that you don't know what is important and what's not. Read on for more information about using automotive r134a in a refrigerator and vice versa. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. Its chemical symbol is CH2FCF3. However, you can convert R12 to R134a by yourself, save money and keep all the tools purchased. I'll report back on the aux fan on performance next. I have some experience with auto a/c but not too much. Where would I get some basic info on it, I know nothing about it. How dumb!I will jumper the aux fan and redo the test. 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. The global warming potential of R134a is 1430. . Bad Car A/C Expansion Valve Symptoms. Its chemical symbol is CCl2F2. All fans must work at 100% of the OEM rating. Therefore, its most suitable for both commercial and domestic environments. On the other hand, R12 has a global warming potential of 10,910. There are three different refrigerants officially sanctioned by the EPA for automotive usage: r-12, r-. The old compressor used R12 and the new unit will be R134a. 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. Any suggestions, or do you need to know the hi/lo readings? Using R134a requires that Polyolester (POE) lubricant must be used in the compressor. Yes it will work with either Refrigerant! How about evacing 1 pound of refrig from the system, and then putting 1 lb of pure R12 back in? R134a has the chemical formula CF3CH2F and is known as tetrafluoroethane. If you you dont have the free time to play then you are better off to pay a technician. R134a systems operate at higher discharge-side pressures than R12, which can cause compressor seals to leak. Rules governing changing from the former to the latter differ between countries. If you have a York, and it is equipped with service valves, you can check & adjust the oil level without discharging the system. I don't recall all the details, but starts off with the largest parallel flow condenser and improved fans. 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. Well, I'm not sure it is 'fine' - it doesn't cool very well in 95F weather. -------------------------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! At 40, it is 35psi, which is a difference of 8.9psi. Also called the orifice tube. What is a good differential? 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. 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. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. An extra half ounce? Mine was 61, so the system is not working as it is supposed to. 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. Just because the radiator does not boil people assume that the cooling system is ok. So, instead of using R12, other better options include R401b, R134a, R401a, etc. It is a known suspect that lets heat into the heat exchanger/core even when off because the mono-valve is on the exit side of the heater core. The pressure/temperature curves for R-1234yf and R-134a are very similar. In short, NO! Don't like the sound of custom parallel condensor. 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. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. Interestingly, theres one oil type that works perfectly with both types of refrigerants. Debug the condensor (I am a computer nerd after all!)3. You should keep in mind that recharging your air conditioner improperly could result in more serious damage. and he synthesized R-134a in 1936, 5 years after R-12 was . When you add fluorescent tracer dye to with the refrigerant oil it helps to track down leaks that push oil out of the system. At 2000rpm, windows open, highest fan, hi pressure stabilized at 225 psi, low 25psi.Ambient 81F, vent 61F. Once you have replaced the OEM condensor with a PF unit, you will need to make custom hoses to mate with your OEM system. What is the refrigerant property involved that has caused this? 4 Stars & Up & Up; 3 Stars & Up & Up; 2 Stars & Up . Is there a source of valves by, say, eaton number? Get to the point where I can walk without crutches2. Back in that era, my business associates drove those things, brand new, and maybe I should take my Cadillac instead, no they wouldn't be caught dead in a Caddy, people of our esteem should be driving an MB. A comparison between R12 vs. R134a temperature will show that R12 has a higher temperature than R134a. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. R134a and R12 are both refrigerants used in vehicle air conditioning systems. R-12 is no longer used or produced in many countries and remaining quantities have skyrocketed in price. It would make a big difference at idle ,in traffic!! Neuro spine Super Speciality Clinic - Above Apollo Pharmacy, Bangarpet Circle, Kolar - Bangarpet Road, Kolar Town. "Howdy, Folks!" R12, on the other hand, is called chlorofluorocarbon (CFC). 1) Look Here at the available sizes of PF condensors.2) Go look at your vehicle's condensor & mounting. In practice this means that the car can overheat and the aux fan will stay off! Most importantly, the oil used in the plant must always be compatible with the refrigerant used. R12 systems used mineral oil, but unfortunately mineral oil doesn't dissolve in R134a. I'm also thinking maybe I should go to R134 - it might work better with the right amount of oil and the correct expansion valve. 1) Warm Air From Vents. Then I'll put the ball valve in on the coolant and test it and see what we have. And no, you cannot "drain' excess oil out. The flammables have hydrocarbons. Related products. This is the part that controls the system pressures. The original expansion valves work very well with R134a. 30 deg is pretty coldSystems generally run between 40 and 43 deg. Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. With new R12 no longer being manufactured, the market price soared to $100/pound. 4.R404A R134a increased mass transfer resistance to reduce the transmission chamber heat coefficient, while R507 heat transfer coefficient is higher than R404A. 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. Then at least I'd know really where I am on it. 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. The first vehicle that used the R1234yf refrigerant was the 2013 Cadillac XTS. -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. 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. The substitute that we used for R-12 was the new HFC called R-134a. The current expansion valve is FF - 1/4 - C. Is it neccesary to replace this valve? = R134a Charge Level. Add to cart. compressor, condenser, evaporator and expansion valve are specifically designed for use with R134a. I think the way to go here is1. The common problem when converting from R12 to R134a is lack of knowledge or equipment. They plug all the time. Please enter the name by which you would like to log-in and be known on this site. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. $21 . The pressure at low temperatures is nearly the same between 12 and 134a. Put a relay on the compressor clutch to the aux fan (I like that idea - makes a lot of sense)How does that sound? But R22 is almost equally damaging. Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. At this point it is time to make an appointment with the a/c shop. The best replacement for R134a is R1234yf, while R12 refrigerant replacement was R134a. This is 11F off the FSM performance graph - vent should be around 50F. Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. Also, R134a cylinders are light-blue in color. This is not to say that one of these small retro-fit kits cant be used, however to be used wisely. 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. If the system was upgraded by a professional it should have an upgrade sticker. That way I will have reduced the oil by about 1/3 (assuming the oil is mixed evenly through the system). We've updated our forums!Click here to visit the new forum, Year: 1983Make: MercedesModel: 240DEngine Size: 2.4Refrigerant Type: R12Ambient Temp: 90Pressure Low: 35Pressure High: ?Country of Origin: United States, Hi, this is my first post, so please take it easy on the noob.
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