difference between r12 and r134a expansion valve

Before we mentioned that you can add approximately 5-6 ounces of ester oil to the compressor. A discussion of the relationship between valve capacities and superheat set-tings can be found in Bulletin 10-9. 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. That switch should close @ 52c. Whenever its exposed to the environment, it changes to a gas. Just because the radiator does not boil people assume that the cooling system is ok. Vent temperatures slowly go down to around 50F with hi speed driving. It won't be optimal, though. If you have a perfectly operating system using R12 you do not have to drop what you are doing and convert to R134a. $21 . 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. . Very nice! Its duty is to convert toxic gasses produced by the engine into A brake cleaner is a powerful solvent for cleaning dirt from the brakes and other car components. If you have the work done, be sure you find a true "A/C" shop that can make up lines. The larger line at the expansion valve is the suction line. There are significant differences between R12, R134a, and R513A, which must be considered when handling, processing, applying, or retrofitting with these refrigerants. R12 Expansion Valve with R134A charge? - Maverick We, the Rxmechanic team, have presented a well-detailed comparison of R134a vs. R12. Is there a source of valves by, say, eaton number? R134a is the most widely accepted alternative automotive refrigerant used to replace R12. 3) A TXV optimized for 134a will be ok with R12. I think the way to go here is1. Automotive Replacement Expansion Valves & Parts; Industrial & Scientific; Customer Reviews. In most cases, the systems used have varied components, designs, and service ports. 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. difference between r12 and r134a expansion valve Further production of R12 was banned in some developed countries by the Montreal Protocol because of its harsh effect on the ozone layer. #13. I mean, really a lot. They can be mounted quite easy,and there is a mounting kit that helps to hang it. difference between r12 and r134a expansion valve. The only difference I can imagine would be the recharge connection. Like say half a can or so recharge come springtime warm weather or something. Unfortunately, the R12 refrigerant doesnt always blow cold air. A Lot of the fins are bent, especially at the top. I've done the FSM test and with 81F ambient, the vent should be 50F. Could that be screwing up the systems performance?Anyway, when I installed the system, the new TXV (is that short for expansion valve?) Put a relay on the compressor clutch to the aux fan (I like that idea - makes a lot of sense)How does that sound? The good thing is that after you convert to R134 you can top off the system easily and cheaply. It is also used in automotive car conditioning and the plastic industry. 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. This means that it has a high potential of causing depletion to the ozone layer. The cure is to use the newer R134a compressors is sealing washers that are different thickness. Condensers designed to release greater amounts of heat help to expel the greater amount of heat which R134a removes from the cars interior. But I don't want to waste your time. If your cars system has a sufficient condenser design and air flow to expel the greater amount of heat extracted by R134a, then by all means you should convert over when the time comes. This may be the source of your oil confusion. Its chemical symbol is CCl2F2. AC R12 to R134A Conversion | MR2 Owners Club Forum Thus, when the system is running, condensing the CO2 is not a problem. difference between r12 and r134a expansion valve July 3, 2022July 3, 2022. Make sure to wear safety gloves, goggles, and shoes when theres a possibility of exposure to the chemical (R134a). Look deep into the fins. B. As an example, let's say the R12 charge specification is listed at 2 lbs. The best replacement for R134a is R1234yf, while R12 refrigerant replacement was R134a. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines. It is made up of carbon, hydrogen, and fluorine. The pressure at low temperatures is nearly the same between 12 and 134a. Generally, the new amount is 75-85% of the quantity advised by the manufacturer. 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. If 50 degrees across the cond. Hot coolant migrates up through the core by convection (is that the word? 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. Therefore, its most suitable for both commercial and domestic environments. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores. That way I will have reduced the oil by about 1/3 (assuming the oil is mixed evenly through the system). After the optimum refrigerant charge is determined the car should be test driven to check for performance of the system. Depending on which circuit diagram fits your car (cough, no vin list exists) you have either one or two switches controlling the aux fan. Dimensioning of refrigeration components - part 2 - Danfoss 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. Hopefully after you have read this entire page you will have enough information to determine which type of refrigerant is best for you. It is mixed with the freon for the most part, and does accumulate in all components in small amounts. The #1 question asked by NEW MEMBERS. Generally this works well for the whole system. It is made up of carbon, hydrogen, and fluorine. R134a has the chemical formula CF3CH2F and is known as tetrafluoroethane. Ask Our Pros-Owner Assistance - NO DIY advice will be given. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. The difference between R12 and r134a is the BTU carrying capability. Comparatively, larger R134a molecules should take more space, and a smaller amount might be required. A/C receiver difference between R12 and R134a? a 50f delta across the condensor is good, but I suspect that is an idle reading. The oil used in R12 and R134a are different and not compatible. 4.3 out of 5 stars 491. ambulance tailgate conversion Most of all the differences gravitate to longevity, functionality, and safety. Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. The cost of recharging the air conditioner is between $150 to $500. The next piece of equipment to track down leaks is a leak sniffer. Bohica, I appreciate your help with this. 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. Table 1 summarizes the technical characteristics of three potential R134a alternatives. difference between r12 and r134a 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. 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. 3) A/C Compressor Always On. Swapping the components isnt a herculean task, but recharging the AC is a challenge. 4.R404A R134a increased mass transfer resistance to reduce the transmission chamber heat coefficient, while R507 heat transfer coefficient is higher than R404A. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. 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. If you have a York, and it is equipped with service valves, you can check & adjust the oil level without discharging the system. 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. 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. Bad Car A/C Expansion Valve Symptoms. 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. 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. 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. Inhalation of vapor: Inhaling a large amount of R134a vapor can lead to drowsiness, temporary nervous system depression, and lethargy. Your average garage that works on a/c on the side probably would not have this. In this study, without the need for major modifications to the bus air conditioner, the variation of the ejector dimensions according to different parameters has been investigated in the case of using the R1234yf, R1234ze(E), or R600a refrigerants, which may be a substitute for R134a as a refrigerant due to . 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. Later model cars that come with 134A will have 134A only connectors. The original rubber a/c hose lines in your car will leak out R12 through the hoses lining. Is it exponential, squared? Participate in over 40 different forums and search/browse from nearly 3 million posts. Please enter the name by which you would like to log-in and be known on this site. We consider the the various types alternative refrigerants that are illegal or not approved to be in two sectors: non-flammables and flammables. If the system was upgraded by a professional it should have an upgrade sticker. R12 is used in several applications like low temperature, medium temperature, and high-temperature applications. In a car ac, using this type of freon 20 years ago was difficult. 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. R134a Refrigerant Recharge Kit with BPV31 Bullet Piercing Valve and R134a Quick Coupler, R134a/R-12/R-22 Freon Refrigerant Hose Can Tap Kit for A/C System - Easy to use. In short, NO! Any suggestions, or do you need to know the hi/lo readings? R1234yf. 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. Does it matter - assuming both are new & uncontaminated? 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. 5. Compared with the cost-performance ratio, R507 is 30-40% . R1234yf is more environmentally friendly and has a global warming potential of 4. 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. Yes, the 50F diff (160-110F) on the condenser was at idle, and ambient was about 90F. You'll want the expansion valve matched to whatever refrigerant you're using. The current expansion valve is FF - 1/4 - C. Is it neccesary to replace this valve? 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. Do I leave the orignal condensor in, etc?Thanks. system of 0.33 TR and refrigerant used was R12. R-12 is no longer used or produced in many countries and remaining quantities have skyrocketed in price. 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. 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. Then when it is switched off for a few minutes and then back on, the air cools again. I would not do a 134a conversion without a PF condensor. You can use the R134a retrofit capacity chart for this purpose. difference between r12 and r134a expansion valve Best for varieties of operating conditions: Its boiling point is -21.6 Celsius. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. The ARPA Zone/Open Membership Discussion Forums. The flammables have hydrocarbons. The reason is that the vehicles, for instance, manufactured currently configure the engine for R1234yf refrigerant, making no provision for replacement. Its highest value is 1. 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. Recovery & flushing is the only way out of an oil overcharge in your vehicle.B. This is an electronic tool that sucks in air through a tube and across a sensor. Its among the greenhouse gases and will keep adding the current problem of heat not leaving the earths atmosphere. R134a vs. R12 - Griffiths I'm not sure. The evap is hard to get at. and an evaporator core and expansion valve that are optimized for R134a . How an A/C Expansion Valve Works. An extra half ounce? Bookmarks: Digg; del . At 2000rpm, windows open, highest fan, hi pressure stabilized at 225 psi, low 25psi.Ambient 81F, vent 61F. Rules governing changing from the former to the latter differ between countries. In cases such as this, the required capacity value of the expansion valve with R134a is reduced by 30% (correction factor 1.42). ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. 3 ounces? ESP when a compressor has frozen. Yes it will work with either Refrigerant! -------------------------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. 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. I have the original (R12) style expansion valve in the Maverick AC system. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. R12 and R22 are both now banned by the EPA in the United States. B. 5) A/C System Failure. Since 2010, all home AC systems manufactured use a refrigerant like R134a that has zero ozone depletion potential (ODP). All fans must work at 100% of the OEM rating. For instance at 25 F the pressure of R-12 is 24.6 PSI and the pressure of R-134a is 22.1 PSI. The newer valves and switches will work with both refrigerants. Once you have replaced the OEM condensor with a PF unit, you will need to make custom hoses to mate with your OEM system. Minor adjustments to the expansion valve and other controls may be necessary for some plans. 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. Can I order a valve based on the original eaton number? CONCLUSIONS The differences in the theoretical C.O.P.H calculated for R12 and R134a are consistent with values quoted in the literature. For R12, its mineral oil. R-134a XV for R-134a use. We say generally because the vehicle manufacturer may have a formula already worked out for the R134a conversion process. Though - the valve for a 1991 says R12 on it, and for a 1994, it says R-134a. Most vehicles manufactured before 1993 have the R12 A/C system. Measure what you have now.3) Go back to the page in step one, and find the largest condensor you can put in your vehicle. R134a refrigerant is about 10% less efficient in moving heat than R12! Just had knee surgery yesterday, so I"M not exactly hopping around too well. Interestingly, theres one oil type that works perfectly with both types of refrigerants. The money you will save by will pay for the R12. So to keep things simple and to avoid controversy and politics we have R134a. had writing on the side that said R134a. R134a. The difference between the two is about 10,000 btu/h. sparkee said: Thanks for the Service Bulletin. R 134A is designed for the high demands of an automobile AC and cannot be used on refrigerators due to pressure differences. First, differences in physical properties: 1, insoluble R12 compressor oil is used (to reduce the lubricant) 2, dissolved sealing materials are used (resulting in refrigerant leakage) 3, easy to damp (so easy to internal . Its chemical symbol is CH2FCF3. AFAIK, there is no clutch on the engine fan on the 240D. The aux fan seems to be working fine - it switches on occassionally. 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. R12 is simply too expensive for a 25+ year old A/C system. The first vehicle that used the R1234yf refrigerant was the 2013 Cadillac XTS. Next I'll jumper the aux fan. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge. But R22 is almost equally damaging. 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. 2) Frost on the Vents. 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. 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. Related products. evarporator, expansion valve plus flushing out the full system and replacing all the o rings. However, R12 refrigerants are still used as fire retardants in aircraft and submarines. 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. In the automotive world, the replacement for R12 was R134a. Warning: "continue" targeting switch is equivalent to "break".Did you mean to use "continue 2"? Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. Nice to use new gadgets! R12 is heavier than R134a and has smaller molecules. Kommentare . 1.5 ounces - hmmm. Recharge the compressor with a/c ester oil and a tracer dye. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. 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. Below are the major differences between R134a and R12: The chemical composition of R12 and R134a differ. R134a is called tetrafluoroethane (HFC). Edited: Tue July 17, 2007 at 3:25 AM by bohica2xo, I believe there is only one switch - the refrigerant switch. Replace the drier with a drier that has a desiccant that is R134a compatible, use new R134a o-rings. The analysis focuses on Coefficient of Performance for . It won't be optimal, though. This kit comes complete with Expansion valve, o-ring kit, and 1ft. 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. There are other refrigerants: some of which may work, some of which dont work, some of which will destroy your a/c system and some of which are dangerous. That is for the compressor, drier, expansion valve and condenser. For example, if your system originally had 36 ounces of R12 then you multiply that by .80 and you have 29 ounce of R134a. 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. difference between r12 and r134a expansion valve . Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. With the A/c off hi and lo were both at 105psi. difference between r12 and r134a expansion valve. To ensure the right charge, you must fill the new system with between 75 and 85% of the factory-set capacity for optimal cooling. With R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. . Heres R12 vs. R134a pressure chart. 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. Is the information not applicable to the old Pantera system? . -------------------------"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 oil is spread all over your system when it is at rest. Stopleak is also risky. Gnats & mosquitos will clog deep. Not osmosis, but you know what I mean). El juny de 2017, el mateix grup va decidir crear un web deDoctor Who amb el mateix objectiu. R12 was once used in many air conditioning units as a refrigerant or cooling agent. I'll report back on the aux fan on performance next. According to Wikipedia, There is such a thing as "r132a" (1,1-Dichloro-2,2-Difluoroethane), however there is no indication of it being a commercially produced refrigerant. The common problem when converting from R12 to R134a is lack of knowledge or equipment. You will be fine with a 134a-compatible TXV running R12.