difference between r12 and r134a expansion valve

This kit comes complete with Expansion valve, o-ring kit, and 1ft. and feeds it through an expansion valve. 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. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. Reattach the hose lines using new R134a compatible o-rings, lightly lubricate with compressor oil. There is NO reason to retrofit a vehicle to R-134a as long as the R-12 system is cooling properly and contains a normal charge of refrigerant. R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. ing the expansion valve, a maximum opening superheat of 7F, and a standard factory air test superheat setting. I cleaned the evap as best I could, if that is what you are getting at. Gain access to our free AOP (Ask a Professional) Section to get real answers for your questions. 4) Inconsistent Airflow. #4. 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. The crossover point is approximately at 64F. R12 is CFC: Even though R12 is one of the most commonly used refrigerants, it is CFC. Mine was 61, so the system is not working as it is supposed to. Here are the basics for converting a system that does not have a charge of R12, its empty. Neuro spine Super Speciality Clinic - Above Apollo Pharmacy, Bangarpet Circle, Kolar - Bangarpet Road, Kolar Town. Since then, the industry standard has been R134a, which is an efficient replacement. We consider the the various types alternative refrigerants that are illegal or not approved to be in two sectors: non-flammables and flammables. Any ideas from the info above? In most cases, the systems used have varied components, designs, and service ports. 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. R404a for freezing of product. It is a haloalkane and hydrofluorocarbon (HFC) refrigerant that has thermodynamic properties, potential global warming for one hundred years, and insignificant ozone depletion. Are r12 and r134 fittings different? Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. The money you will save by will pay for the R12. When you add fluorescent tracer dye to with the refrigerant oil it helps to track down leaks that push oil out of the system. Table 1 summarizes the technical characteristics of three potential R134a alternatives. We, the Rxmechanic team, have presented a well-detailed comparison of R134a vs. R12. -------------------------"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." 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. I bought a relay to put on it connected to the compressor clutch. 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. 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. Even if the system leaks, repairing the leaks and recharging it with R-12 is usually the best repair alternative. But I don't want to waste your time. difference between r12 and r134a expansion valve. 05-25-2017 02:14 AM. Look deep into the fins. I'm not sure. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. You are indeed 20% out of the OEM spec for cooling. The butylcellusolve or the citrus solvent will dissolve the carcass in a few minutes. _____ 2012 E350 2006 Callaway SC560 . In cases such as this, the required capacity value of the expansion valve with R134a is reduced by 30% (correction factor 1.42). Large temperature difference between expansion valve inlet and outlet oReplace expansion valve Air . But R22 is almost equally damaging. At this point it is time to make an appointment with the a/c shop. Paul:A 1983 240D should have a York compressor on an OEM system. absorb by the evaporator to insure all liquid refrigerant entering the evaporator. R12 is highly destructive to the earths ozone layer. 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. All fans must work at 100% of the OEM rating. R-134a XV for R-134a use. The safe high side pressures are determined with a PT (pressures and temperatures) chart. However, it was found to be a very bad gas for the environment. Minor adjustments to the expansion valve and other controls may be necessary for some plans. 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. With R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. hardly noticable. Please enter the name by which you would like to log-in and be known on this site. That's a lot isn't it? Be sure to test @ 1500 to 2000 engine rpm, and record the ambient temp as well. In practice this means that the car can overheat and the aux fan will stay off! Make sure visiually that no large gaps exist that would allow the air to bypass the condensor on the way to the radiator.B. 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. And, unfortunately a small high side pressure gauge on a short hose. 30 deg is pretty coldSystems generally run between 40 and 43 deg. It was later found that R-134a had a very high Global Warming Potential, or GWP, number. 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. Just because the radiator does not boil people assume that the cooling system is ok. 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. Moreso, it had been banned. 3) A TXV optimized for 134a will be ok with R12. The cost of recharging the air conditioner is between $150 to $500. R134a. I am ordering new parts, and planning to convert my system to R-134a. R134a is NOT less efficient than R12 Actually R134a is more efficient. A slow loss of cooling at city speeds is usually related to condensor capacity & airflow issues.You could improve the cooling capacity by replacing the condensor with a high effeciency parallel flow unit. 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. 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. 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. With tube & fin condensors in MVAC applications there is never "too much" airflow. Figure 2 shows the different phases and pressures the refrigerant . R134a systems operate at higher discharge-side pressures than R12, which can cause compressor seals to leak. (The .133 is the 300D Turbo).So, what does your compressor look like?B. A slow loss of cooling at city speeds is usually related to condensor capacity & airflow issues. might be due to charge or different compressor and age. It is made up of carbon, hydrogen, and fluorine. The larger line at the expansion valve is the suction line. I don't want to be chasing ghosts. 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 . It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. Very interesting! sparkee said: Thanks for the Service Bulletin. July 3, 2022July 3, 2022. Spray it deep, and let it sit for a few minutes. One thing at a time here, and slowly, the knee is not up to jumping around like I used to at the moment. Paul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. 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. 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 . But as there's not a big difference, people say you can suffice with either. The difference really shows up on the high side. VerticalScope Inc. All Rights Reserved. #13. R-401b is the mixture by weight of 61% R22, 11% R-152a and 28% of R-124. Can I use the one for the R-12? I found that in the..Maxposition on the control it will have the compressor running all the time. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyers guides, and car and tools comparisons. If the system was upgraded by a professional it should have an upgrade sticker. Trinary Pressure Switch quantity. It would make a big difference at idle ,in traffic!! It cycles on off in med (or low for that matter)Gotta tell ya. Electric fans do wear out. In sum, R12 has done more bad than good. Low refrigerating effect per pound: In comparison to other refrigerants, the refrigerating effect of R12 per pound is low. That way I will have reduced the oil by about 1/3 (assuming the oil is mixed evenly through the system). Skin contact: If the R134a (liquid) comes in contact with your skin, it could cause a burn. 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. 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. Thanks so much Bohica - you've save me many more hours of fruitless speculation. You'll want the expansion valve matched to whatever refrigerant you're using. 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. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. Only show this user. The cure is to use the newer R134a compressors is sealing washers that are different thickness. You may need to adjust the valve in a bit to get desired superheat. -------------------------"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest." Condensers designed to release greater amounts of heat help to expel the greater amount of heat which R134a removes from the cars interior. |. Stopleak is also risky. 1) Warm Air From Vents. R-134A has a slightly lower pressure at evaporator temperatures (30-40 degrees), but R-134a also has a much higher pressure at condenser temperatures (120-150 degrees). Pray I can let some oil out of the compressor without losing my precious R12. how to get to disney springs from boardwalk / bb dakota plaid jacket canada / difference between r12 and r134a expansion valve. The best oil that runs well with R134a is PAG oil or Polyalkylene Glycol. I know this is bad, etc, and deposits on the metal can act as insulators. Failure to abide by the EPA regulations can result in expensive fines for either you or your service technician. Hot coolant migrates up through the core by convection (is that the word? The only mechanical differences between an R12 system and an R134a system are that R134a systems typically have larger condensers and more powerful compressors. For instance you can evacuate FRIGC FR-12 into a refrigerant recovery bottle that has R134a in it or visa versa. What is the refrigerant property involved that has caused this? video clubhouse baseball; nick fairley draft profile; ben davis work pants Bottom line, R134a simply doesn't cool as well as R12. CLUTCH CYCLING SWITCH. However, R134a is better than R12. -------------------------"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." Took me a while to figure that one out, and how to say that. 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. It's best to determine on a case-by-case basis while monitoring system pressures and output air temperature. The condenser water inlet temperature and flow rate are controlled with the use of a . Is there a graph? 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. 10,000BTU conduction heating? The typical scenario here is when the car owner buys an inexpensive retro-fit kit from the local auto parts store. 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. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge. The mechanical fan & clutch should be checked as well. In short, NO! The experimental values of C.O.P.H obtained with the R134a/ester charge were 20.2% However, take note that R134a refrigerants are manufactured specifically for automotive air conditioners. R404a is a zeotropic blend with a temp glide , because of the mixture of 2 or more refrigerants. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. Quick View. 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. Though I have seen em run as cold as 12 deg F. If the thermo switch is malfunctioning. 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. 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. . It slowly gets warmer and warmer in the car, even at highway speeds. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. When the sensor detects the refrigerant leak the sniffers lights glow and the sniffer makes a noise. Any advice appreciated. ThanksPaul -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. We say generally because the vehicle manufacturer may have a formula already worked out for the R134a conversion process. Additionally, R134a was introduced as a replacement for R22 and R12 in high and medium-temperature refrigeration systems like domestic and commercial chillers. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. R134a has an ozone depletion potential of 0, implying that it has a slight effect on the ozone layer. 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. Yes, this was a smokers car. It is usually sold under the brand name, Freon 12. He used thermostatic expansion valve and Capillary tube for analysis with R12. 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. Its chemical symbol is CH2FCF3. Is that reasonable?Vent airflow is good, I think. So that indicates it is cooling well there doesn't it? R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. The larger fitting goes on the discharge port and the smaller fitting goes on the suction line or compressor inlet / suction port. I don't have the FSM matrix handy for that 123.123, but a 123.133 shows a test rpm of 2,000 - and vent temps between 54f & 66f at 91f to 95f ambient. Blows pretty hard on full. Debug the condensor (I am a computer nerd after all!)3. The OEM spec is 2300 rpm @ 12.6v (engine stopped fully charged battery). and an evaporator core and expansion valve that are optimized for R134a . The #1 question asked by NEW MEMBERS. (On firewall where A/C lines go into cab.) The old compressor used R12 and the new unit will be R134a. It didn't seem too dirty though - I don't think it is the problem, but I could be wrong. 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. They examined the two configurations of capillary tubes i.e. Hope this helps. Your average garage that works on a/c on the side probably would not have this. 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. The problem with not being an expert is that you don't know what is important and what's not. At the time I thought nothing of it, but now I am thinking maybe that is contributing to the system not working as well as it could. All pre-97 XJs use systems with the same basic operating principle, although the parts do change a bit. Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. Nick, I hear you - there maybe nothing to do here. An orifice tube is just a fixed nozzle that pisses refrigerant into the evaporator without any sort of feedback. Nevertheless, if your application is configured only for R12, then you can use it or consider replacing the applications engine. Whether R134a performs as well as R12 in any given a/c system depends upon system components and the amount of R134a used. 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 . Not going to mess up your 'do, but you can feel it. 2) Frost on the Vents. You do not need to replace the expansion valve in most cases. 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. The name of the oil is Polyol Ester (POE). Gnats & mosquitos will clog deep. 3 ounces? A lower GWP alternative to R-134a had to be found and thus we have the new 1234yf. evarporator, expansion valve plus flushing out the full system and replacing all the o rings. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. We are an automotive mechanic blog that helps mechanics and car users to find the most recent and accurate technical and repair information for their cars. R 134A is designed for the high demands of an automobile AC and cannot be used on refrigerators due to pressure differences. The system has been previously converted to R-134a. The oil used in R12 systems is not compatible with R134a refrigerant. Bookmarks: Digg; del . The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. BTW, I use a stick thermo in the vents and the laser on the condenser. This is not to say that one of these small retro-fit kits cant be used, however to be used wisely.

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