Low refrigerating effect per pound: In comparison to other refrigerants, the refrigerating effect of R12 per pound is low. An extra half ounce? The cure is to use the newer R134a compressors is sealing washers that are different thickness. Your decision could be made based on economics, environmental concerns, or both. Components Coils, Heaters, Motors, etc. Refrigerators generally utilize R22, R32, or 410A-based coolants as their cooling agent. Safe but sorry! 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. Different correction factors are applied to other refrigerants. in /nfs/c05/h04/mnt/113983/domains/toragrafix.com/html/wp-content . You can use the R134a retrofit capacity chart for this purpose. 4.3 out of 5 stars 491. Can I order a valve based on the original eaton number? 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. El juny de 2017, el mateix grup va decidir crear un web deDoctor Who amb el mateix objectiu. The money you will save by will pay for the R12. It's helluva humid and hot here in north florida, and I drive around all day for my job. If the charge is low the compressor will cycle on/off in the max AC position. Note that passwords are case-sensitive. Paul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. Poc temps desprs van decidir unir els dos webs sota el nom de Xarxa Catal, el conjunt de pgines que oferirien de franc sries doblades i/o subtitulades en catal. For instance you can evacuate FRIGC FR-12 into a refrigerant recovery bottle that has R134a in it or visa versa. Looks like a couple of things happening here1) 80's vintage Eurocars were not "meat lockers". R-134a XV for R-134a use. 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. Superheat you can consider to be the additional amount of heat. Depending on which circuit diagram fits your car (cough, no vin list exists) you have either one or two switches controlling the aux fan. 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. R134a systems operate at higher discharge-side pressures than R12, which can cause compressor seals to leak. and he synthesized R-134a in 1936, 5 years after R-12 was . and feeds it through an expansion valve. 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. The condensor airflow drops off as the fan clutch dies slowly. look at the difference! . I've done the FSM test and with 81F ambient, the vent should be 50F. Then when it is switched off for a few minutes and then back on, the air cools again. You may have heard of a friend that did the job himself with borrowed equipment and 12 or 16 ounce cans of refrigerant. R134a refrigerant is about 10% less efficient in moving heat than R12! Its chemical symbol is CCl2F2. You do not have to split up the 5-6 oz of oil and add it to each component, just simply put it all in the compressor as it will move throughout the whole system once the system is operational. It is possible I have 10 ounces (250 ml) in the system. They can be mounted quite easy,and there is a mounting kit that helps to hang it. and recharged with mineral oil and 2.2 lbs R12. Also, if you want to know what happens if you put R134a in an R12 system, you should first confirm if the R12 system can be replaced or if the refrigerants can be mixed. Minor adjustments to the expansion valve and other controls may be necessary for some plans. And by matching the correct amount of R134a to use in a given vehicle, correcting the superheat of the expansion valve (if necessary), you can in some manner nearly balance or match the amount of heat drawn out by the evaporator and released by the condenser. 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 . According to the thermodynamic characteristics, it is close to the R12 freon, however, it is 10-15% worse in terms of cooling capacity and is more fluid. 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. Bad Car A/C Expansion Valve Symptoms. It won't be optimal, though. If there is no pusher fan, and you have the room, put one in. 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. I don't recall all the details, but starts off with the largest parallel flow condenser and improved fans. Or is there always room for improvement, the more the merrier. June 21, 2022 difference between r12 and r134a expansion valve . . A/C receiver difference between R12 and R134a? Nick, I hear you - there maybe nothing to do here. R12 is heavier than R134a and has smaller molecules. I think the way to go here is1. 30 deg is pretty coldSystems generally run between 40 and 43 deg. 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. You either get a system that will function well with R1234yf or get any other type. R1234yf is more environmentally friendly and has a global warming potential of 4. The next piece of equipment to track down leaks is a leak sniffer. Instead, top off R12 with R134a refrigerant. R404a is a zeotropic blend with a temp glide , because of the mixture of 2 or more refrigerants. These two refrigerants are the older types and are not used in newer refrigeration and air conditioning systems. If you have the work done, be sure you find a true "A/C" shop that can make up lines. Tamb oferim en VOSC el contingut daquestes sries que no es troba doblat, com les temporades deDoctor Who de la 7 en endavant,les OVA i els especials de One Piece i molt ms. I just got some hi/lo side gauges so I'm going to take readings, if they are needed. Generally the system will be initially charged with approximately 80% to 85% of the original amount of R12, using R134a. Questions About Becoming A Professional Member? Recharge the compressor with a/c ester oil and a tracer dye. Shorting the plug for the refrigerant switch should run the fan when the compressor is on. . Add to cart. 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. So that indicates it is cooling well there doesn't it? It is mixed with the freon for the most part, and does accumulate in all components in small amounts. 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. That switch should close @ 52c. The butylcellusolve or the citrus solvent will dissolve the carcass in a few minutes. It didn't seem too dirty though - I don't think it is the problem, but I could be wrong. Trinary Pressure Switch quantity. Further production of R12 was banned in some developed countries by the Montreal Protocol because of its harsh effect on the ozone layer. I don't know where it is getting the switch off command, or why the vent temp drops steadily. Only show this user. Vent temperatures slowly go down to around 50F with hi speed driving. 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. R134a and R12 are both refrigerants used in vehicle air conditioning systems. R134a refrigerant is lighter than R12. It is perhaps possible to locate a unit with a company that purchases close out or distressed merchandise. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. How dumb!I will jumper the aux fan and redo the test. A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . We say generally because the vehicle manufacturer may have a formula already worked out for the R134a conversion process. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. If you have 10 ounces of oil in the system, that is contributing to the poor performance as well. This is due to many facts: R134a refrigerant is about 10% less efficient in moving heat than R12! Then again, there are two different expansion valves. The symbol implies that R12 is a composite of carbon, chlorine, and fluorine. Agram a retevis rt22 password i bastrop county district clerk records el material que oferim als nostres webs. -------------------------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. Its chemical symbol is CH2FCF3. Thus, when the system is running, condensing the CO2 is not a problem. Some cars have both an engine coolant temp switch & a refrigerant temp switch, others only the refrigerant switch. of refrigerant insulation tape. We ALWAYS want to know the pressure readings! difference between r12 and r134a expansion valve . The difference really shows up on the high side. Hence, let us continue to fix it. . Energy usage: R134a is less efficient in cooling compared to R12. I'm doing one thing at a time so I know what the cause was. Theres no problem with using R134a in a home air conditioning system because it is a hydrofluorocarbon that doesnt cause environmental harm. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. 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. Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores. The global warming potential of R134a is 1430. R134a is the most widely accepted alternative automotive refrigerant used to replace R12. Its chemical symbol is CCl2F2. 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. 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. 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? I have some experience with auto a/c but not too much. The typical scenario here is when the car owner buys an inexpensive retro-fit kit from the local auto parts store. (The .133 is the 300D Turbo).So, what does your compressor look like?B. R12 systems used mineral oil, but unfortunately mineral oil doesn't dissolve in R134a. Also, they are mostly used in refrigeration and automotive air conditioning systems. In a comparison between R12 vs R134a vs R1234yf, R1234yf will pass as the best refrigerant. All fans must work at 100% of the OEM rating. 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. Biggest you can fit in there is best. The bad thing is I don't know what to do about it. 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. Make sure to get the R12 EXP valve if that is the way you go. 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. Besides, you have a greaseisel. 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. Read on for more information about using automotive r134a in a refrigerator and vice versa. Als nostres webs oferimOne Piece,Doctor Who,Torchwood, El Detectiu ConaniSlam Dunkdoblats en catal. Its chemical symbol is CH2FCF3. With the knowledge of the differences, youll be able to draw a comparison between R12 vs R134a efficiency. As noted, measure up front as best as you can to get as close to the aftermarket dim. However, if it is taken close to a fire flame or any electrical heating element, it disintegrates into toxic products. Rules governing changing from the former to the latter differ between countries. Some say that a chemical reaction can harm the A/C very badly as R134a reacts with mineral oil in some way. Is there a difference between a R134a expansion valve and an R12 TXV? Why wait for 200f on the engine coolant to start the fan? Most importantly, the oil used in the plant must always be compatible with the refrigerant used. What is the refrigerant property involved that has caused this? The experimental values of C.O.P.H obtained with the R134a/ester charge were 20.2% Your old hoses of course will not fit. 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. Jun 17, 2011. Inasmuch as R134a has a global warming potential thats over 1000 times more threatening than carbon dioxide, its better than R12. Is that why expansion valves are specific to R12 or R134A? Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. A. Pressure/temperature plot of R134a vs. R12 is shown in figure 1. You do not want to exceed the systems high side recommendations. The mechanical fan & clutch should be checked as well. Nice to use new gadgets! 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. Whether R134a performs as well as R12 in any given a/c system depends upon system components and the amount of R134a used. 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. had writing on the side that said R134a. Performance doesn't seem to have improved. Please enter a valid email address for yourself. Helical and Serpentine coils. Thanks so much Bohica - you've save me many more hours of fruitless speculation. -------------------------Just another brick in the wallHad a little mule I fed him castor oil and every time he jumped the fence he fertilized the soil, The older expansion valves were filled with the refrigerant they were used with, the replacement valves (today) are filled with a different chemical to work with both refrigerants..Hope this helps-------------------------ChickEmail: Chick---------------------------------------------Freedoms just another word for nothing left to lose, I believe the optimum supercool setting will vary slightly between an expansion valve for an R12, as compared to R134a, system. 4) Inconsistent Airflow. Is that why expansion valves are specific to R12 or R134A? The only difference I can imagine would be the recharge connection. ThanksPaul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. It is made up of carbon, hydrogen, and fluorine. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. I'm going to check the condensor is way clean too. The MB chart shows 360 psi with R12 in some conditions. 10,000BTU conduction heating? Any advice appreciated. Automotive Replacement Expansion Valves & Parts; Industrial & Scientific; Customer Reviews. 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. difference between r12 and r134a expansion valve. 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. 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. 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. 05-25-2017 02:14 AM. Since 2010, all home AC systems manufactured use a refrigerant like R134a that has zero ozone depletion potential (ODP). 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. So if the TXV is OK, and the too much oil situation is not a big problem, then I wonder why the compressor is switching off after about 15 minutes of cooling? -The amount of R-134a needed will typically be 80-90% of the R-12 charge. CR4P). And I already have so much time and money in this a/c project that I REFUSE to cut any corners as small as a TEV.It doesn't help that most people in the business (at least that I come in contact with, present company excluded, of course!) The system has been previously converted to R-134a. R12 contains a chemical called chlorine that destroys the ozone layer, thereby causing potential environmental risk. Stay home and grill your own steaks and stir your own martini. Even if the system leaks, repairing the leaks and recharging it with R-12 is usually the best repair alternative. Therefore, the higher the factor of the chemical (compound), the greater its effect on global warming. In addition, R134a refrigerants are not only used in auto air conditioners, they can be used in freezers, aerosol cans, and refrigerators. So you could likely put off buying those new hoses just a bit longer if you wanted. The reason is that the vehicles, for instance, manufactured currently configure the engine for R1234yf refrigerant, making no provision for replacement. Then I'll put the ball valve in on the coolant and test it and see what we have. 3) A/C Compressor Always On. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. 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. Its highest value is 1. All pre-97 XJs use systems with the same basic operating principle, although the parts do change a bit. I don't think it has any air dams or seals, I'll check to make sure. If your car does not have a high pressure cut-out switch in the AC system then youll need to have one installed (call us if you need help). R12 Expansion Valve = 201 830 06 84 R134A Expansion Valve = 201 830 04 84 Is there a difference after all? If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyers guides, and car and tools comparisons. Still, I have some simple green, so may as well give it a go. That would be the "black death" syndrome. GWP is a measurement of Greenhouse Gases and their effect on Global Warming. 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. Should I do the test again with the the aux fan jumpered? The oil used in R12 and R134a are different and not compatible. 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. The larger line at the expansion valve is the suction line. Rules governing changing from the former to the latter differ between countries. He used thermostatic expansion valve and Capillary tube for analysis with R12. Please enter the name by which you would like to log-in and be known on this site. Is there a difference in the expansion valve for R12 as opposed to R-134a? 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. By using a black light the dye will glow in areas where oil leaks are visible. Neuro spine Super Speciality Clinic - Above Apollo Pharmacy, Bangarpet Circle, Kolar - Bangarpet Road, Kolar Town. The higher the ambient temperature the higher the high side pressure. R12 and R22 are both now banned by the EPA in the United States. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge. This is a great space to write long text about your company and your services. If the system was upgraded by a professional it should have an upgrade sticker. 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. Lasers don't do well on vent temps, a stick thermometer is better in that application. Not going to mess up your 'do, but you can feel it. The cable is adjustable at the valve arm. Hot coolant migrates up through the core by convection (is that the word? 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. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . Compared with the cost-performance ratio, R507 is 30-40% . It does not "pool" to any degree in a large amount anywhere. The current expansion valve is FF - 1/4 - C. Is it neccesary to replace this valve? Big . Existing technology: R134a has been in use in the refrigeration industry for very many years, and theres so much information about the safe use of the product. This is the part that controls the system pressures. Welcome to rxmechanic.com. I'm just trying to help you avoid headaches in the long run. 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. You'll get marginally better performance out of the change as the expansion valve is matches the refrigerant characteristics. In short, NO! Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. Since the hose is the stock hose, you cannot tell what refrigerant is inside. PaulJerky King -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. Moreso, it had been banned. The common problem when converting from R12 to R134a is lack of knowledge or equipment. Swapping the components isnt a herculean task, but recharging the AC is a challenge.