When the sensor detects the refrigerant leak the sniffers lights glow and the sniffer makes a noise. As noted, measure up front as best as you can to get as close to the aftermarket dim. Your decision could be made based on economics, environmental concerns, or both. With the knowledge of the differences, youll be able to draw a comparison between R12 vs R134a efficiency. The expansion valve is designed so that the temperature of the refrigerant at the evaporator outlet must have 8 to 12F (4 to 7C) of superheat before more refrigerant is allowed to enter the evaporator. If the system was upgraded by a professional it should have an upgrade sticker. In a car ac, using this type of freon 20 years ago was difficult. had writing on the side that said R134a. R134a requires the use of synthetic oil! B. The symbol implies that R12 is a composite of carbon, chlorine, and fluorine. Are you sure you have an R4? R12 contains a chemical called chlorine that destroys the ozone layer, thereby causing potential environmental risk. CONCLUSIONS The differences in the theoretical C.O.P.H calculated for R12 and R134a are consistent with values quoted in the literature. To bless the system the technician should attach a R134a sticker somewhere in the engine compartment to note the car is using R134a. 10,000BTU conduction heating? Its chemical symbol is CCl2F2. 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. Recomanem consultar les pgines web de Xarxa Catal per veure tota la nostra oferta. of refrigerant insulation tape. sparkee said: Thanks for the Service Bulletin. . All fans must work at 100% of the OEM rating. Expansion Valves Catalog E-1, July 2012. If you are replacing other system components, such as condensers, driers or hoses, you may need to add more a/c refrigerant oil to the system. Please enter the name by which you would like to log-in and be known on this site. "Howdy, Folks!" ambulance tailgate conversion You can use the R134a retrofit capacity chart for this purpose. Next I'll jumper the aux fan. But as there's not a big difference, people say you can suffice with either. R-134a XV for R-134a use. Automotive Replacement Expansion Valves & Parts; Industrial & Scientific; Customer Reviews. Since then, the industry standard has been R134a, which is an efficient replacement. I think the way to go here is1. 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. . 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. I'll report back on the aux fan on performance next. But as there's not a big difference, people say you can suffice with either. R134a refrigerant is lighter than R12. Given two identical vehicles, each with the same weighted amount of refrigerant, the vehicle with the R134a has the capability to remove more heat (measured in btus) from the vehicle than the same type of vehicle using the same amount of R12. A York oil capacity is listed as "6.5 to 9.6 ounces". 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. Is that reasonable?Vent airflow is good, I think. The non-flammables can have R22 type gas which is not compatible with most rubber hoses or they have gases that contribute to global warming. If you still find it difficult to use R134a in a home AC system, you can check out a comparison of R12 vs R134a fittings to know the refrigerant that best fits the AC system. Unfortunately, the oil only mixes with the refrigerant as a liquid. Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. It won't be optimal, though. difference between r12 and r134a expansion valve. He used thermostatic expansion valve and Capillary tube for analysis with R12. 5) A/C System Failure. With the A/c off hi and lo were both at 105psi. 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. The problem with not being an expert is that you don't know what is important and what's not. Like say half a can or so recharge come springtime warm weather or something. The higher the ambient temperature the higher the high side pressure. Get to the point where I can walk without crutches2. You should keep in mind that recharging your air conditioner improperly could result in more serious damage. For instance you can evacuate FRIGC FR-12 into a refrigerant recovery bottle that has R134a in it or visa versa. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge. I put one in my old daily driver '79 Chevy tank (r-12), and it really made a difference. The best oil that runs well with R134a is PAG oil or Polyalkylene Glycol. This is not to say that one of these small retro-fit kits cant be used, however to be used wisely. The cost of recharging the air conditioner is between $150 to $500. They plug all the time. What is a T/C?4. But R22 is almost equally damaging. 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. ESP when a compressor has frozen. Just because the radiator does not boil people assume that the cooling system is ok. The only difference I can imagine would be the recharge connection. Components Coils, Heaters, Motors, etc. If you have a perfectly operating system using R12 you do not have to drop what you are doing and convert to R134a. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. Below are the major differences between R134a and R12: The chemical composition of R12 and R134a differ. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. Is that why expansion valves are specific to R12 or R134A? -------------------------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! . However, theyre still used in older plants, systems, and the automotive industry. Are r12 and r134 fittings different? What is the refrigerant property involved that has caused this? That is a good thing. This refers to BTU's (heat) moved per pound of refrigerant moved. (The .133 is the 300D Turbo).So, what does your compressor look like?B. Still, I have some simple green, so may as well give it a go. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. However, take note that R134a refrigerants are manufactured specifically for automotive air conditioners. By after changing just about everything, he got what was termed, satisfactory cooling. A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . R12, on the other hand, is called chlorofluorocarbon (CFC). All pre-97 XJs use systems with the same basic operating principle, although the parts do change a bit. 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. This would be a custom install, there is no "drop-in" condensor upgrade for that car.Check for proper fan operation, and clean the air path on both the condensor & radiator. A Lot of the fins are bent, especially at the top. Thomas Jefferson, Thanks,OK, I'm starting to feel a little better about it. Later model cars that come with 134A will have 134A only connectors. Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback. So the steps involved are cleaning out the old oil, replacing all the O-rings, replacing the dryer, replacing the expansion valve, and converting the high and low side connectors from Schrader to quick connect valves. 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. Related products. The system has been previously converted to R-134a. I recommend replacing the expansion valve when you do the swap. Swapping the components isnt a herculean task, but recharging the AC is a challenge. 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. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. The difference between R12 and r134a is the BTU carrying capability. Any advice appreciated. Where would I get some basic info on it, I know nothing about it. This works when the R12 charge specification is listed in pounds. The global warming potential of R134a is 1430. By using a black light the dye will glow in areas where oil leaks are visible. The only difference I can imagine would be the recharge connection. 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. By: james smith underoath; Comments: 0 . It didn't seem too dirty though - I don't think it is the problem, but I could be wrong. Replied by Rich928 on topic R12 or R134a. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. Also called the orifice tube. I just got some hi/lo side gauges so I'm going to take readings, if they are needed. 4.3 out of 5 stars 491. Just had knee surgery yesterday, so I"M not exactly hopping around too well. Use strips of foam to couple the two heat exchangers if necessary.B. Whenever its exposed to the environment, it changes to a gas. The MB chart shows 360 psi with R12 in some conditions. 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. ing the expansion valve, a maximum opening superheat of 7F, and a standard factory air test superheat setting. The flammables have hydrocarbons. _____ 2012 E350 2006 Callaway SC560 . Electric fans do wear out. 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. #19. 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. However, R134a is better than R12. There is only a temperature switch on these cars as far as I recall, and it just switches on the aux fan. 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. I don't want to be chasing ghosts. This drop can affect energy consumption since the plant will operate for a longer period or a larger plant will have to be installed. difference between r12 and r134a expansion valve. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? Can I use the one for the R-12? Besides, R134a refrigerant was manufactured after R12 was banned to help reduce the harshness of the old chemical (R12) on the ozone layer. A lower GWP alternative to R-134a had to be found and thus we have the new 1234yf. Recovery & flushing is the only way out of an oil overcharge in your vehicle.B. R12 Expansion Valve = 201 830 06 84 R134A Expansion Valve = 201 830 04 84 Is there a difference after all? Shorting the plug for the refrigerant switch should run the fan when the compressor is on. You'll want the expansion valve matched to whatever refrigerant you're using. Make sure to wear safety gloves, goggles, and shoes when theres a possibility of exposure to the chemical (R134a). Replacement expansion valve for R134a or R12 A/C refrigerants, with O-ring connections. For R12, its mineral oil. Then at least I'd know really where I am on it. As illustrated in the chart below, the curves below run together nearly throughout the curve, only slightly breaking paths at around 250 psig/150 degrees and above Flammability/Safety R-1234yf has been designated as MILDLY flammable. Its among the greenhouse gases and will keep adding the current problem of heat not leaving the earths atmosphere. This can be very very expensive. Flush with a garden hose - do not use a high pressure washer - you can bend the fins flat & damage the condensor.B. The ratings for evaporator temperatures 40F, 20F, -10F, -40F in the capacity tables are in accordance with ANSI/ARI = R134a Charge Level R12 Expansion Valve = 201 830 06 84 R134A Expansion Valve = 201 830 04 84 Is there a difference after all? evarporator, expansion valve plus flushing out the full system and replacing all the o rings. Thus, when the system is running, condensing the CO2 is not a problem. Thread starter goldNSX; Start date 1 August 2009; Tagged . I remember I had the wrong seals and it leaked some oil, so I put some more in.Bohica - I tested the pressures. Best for varieties of operating conditions: Its boiling point is -21.6 Celsius. How is the vent airflow?I would jumper the aux fan & check the performance. 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. I don't know where it is getting the switch off command, or why the vent temp drops steadily. If the charge is low the compressor will cycle on/off in the max AC position. Use a drop light in the engine bay, and check the air path from the front of the car at night. Edited: Tue July 17, 2007 at 3:25 AM by bohica2xo, I believe there is only one switch - the refrigerant switch. The cure is to use the newer R134a compressors is sealing washers that are different thickness. Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). Spray it deep, and let it sit for a few minutes. At 40, it is 35psi, which is a difference of 8.9psi. Mine was 61, so the system is not working as it is supposed to. 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. These differences in the valve size can be attributed to the correlation of the cooling capacity with the enthalpy difference and the mass flow, which in . The name of the oil is Polyol Ester (POE). The next piece of equipment to track down leaks is a leak sniffer. Thanks for the input. 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. Or is there always room for improvement, the more the merrier. Condensers designed to release greater amounts of heat help to expel the greater amount of heat which R134a removes from the cars interior. With tube & fin condensors in MVAC applications there is never "too much" airflow. absorb by the evaporator to insure all liquid refrigerant entering the evaporator. If you have 10 ounces of oil in the system, that is contributing to the poor performance as well. I found that in the..Maxposition on the control it will have the compressor running all the time. The oil used in R12 and R134a are different and not compatible. Read on for more information about using automotive r134a in a refrigerator and vice versa. R-12 to R-134a Conversion. Ensure you contact a professional mechanic to do the work for you so you dont end up incurring more costs for yourself. For example, if your system originally had 36 ounces of R12 then you multiply that by .80 and you have 29 ounce of R134a. Miscibility with oil: R12 can be mixed with the compressor oil no matter the operating condition. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. 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. Trinary Pressure Switch $ 39.99. 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. I'm putting r12 back in my system, but all of the valves I can for the application (1990 jeep grand wagoneer) say r134a on them. This is a great space to write long text about your company and your services. Minor adjustments to the expansion valve and other controls may be necessary for some plans. 5. Hence, the effect of R12 on global warming is up to 10,000 times higher than carbon dioxide. The experimental values of C.O.P.H obtained with the R134a/ester charge were 20.2% Below are the major differences between R134a and R12: Chemistry The chemical composition of R12 and R134a differ. One thing at a time here, and slowly, the knee is not up to jumping around like I used to at the moment. We've updated our forums!Click here to visit the new forum, Year: 1991Make: Jaguar Model: XJ6Engine Size: 4.0. Hope this helps. R12 was once used in many air conditioning units as a refrigerant or cooling agent. Ask Our Pros-Owner Assistance - NO DIY advice will be given. Instead, top off R12 with R134a refrigerant. I bought a relay to put on it connected to the compressor clutch. Stay home and grill your own steaks and stir your own martini.