difference between r12 and r134a expansion valve

It slowly gets warmer and warmer in the car, even at highway speeds. Expansion Valves Catalog E-1, July 2012. For example, if your system originally had 36 ounces of R12 then you multiply that by .80 and you have 29 ounce of R134a. Large temperature difference between expansion valve inlet and outlet oReplace expansion valve Air . 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? After the system has been tested out it should be checked for leaks. Questions About Becoming A Professional Member? R-401b is the mixture by weight of 61% R22, 11% R-152a and 28% of R-124. Its cylinders are colored white. R134a requires the use of synthetic oil! Boiling Point: R134a refrigerants boiling point is -26.3C (-15.34F). (You must log in or sign up to reply here. Also, they are mostly used in refrigeration and automotive air conditioning systems. A/C systems designed to use R-12 will cool best when charged with R-12 refrigerant. Expansion valves are an active device, they regulate the flow of refrigerant to the evaporator depending on evaporator temperature. Is it exponential, squared? The crossover point is approximately at 64F. 3 ounces? If ambient is 90 (today) and the output of the condensor is 110, that's pretty good isn't it? Recovery & flushing is the only way out of an oil overcharge in your vehicle.B. Performance doesn't seem to have improved. R134a has an ozone depletion potential of 0, implying that it has a slight effect on the ozone layer. It may take a couple of tries to get things really clean.The laser is usually close on clean surfaces, but I prefer a T/C. CLUTCH CYCLING SWITCH. R12 and R22 are both now banned by the EPA in the United States. Components Coils, Heaters, Motors, etc. Hmmmm. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyers guides, and car and tools comparisons. Some cars have both an engine coolant temp switch & a refrigerant temp switch, others only the refrigerant switch. VerticalScope Inc. All Rights Reserved. I'm having the same concern. 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. Then, subtract that result by 0.25 pounds to get the proper amount of R134a charge. The condensor airflow drops off as the fan clutch dies slowly. I bought a relay to put on it connected to the compressor clutch. 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. There are R134a specific valves that operate at a slightly different pressure, but not for any "old" automotive application that I'm aware of. R134a vs R12 refrigerant? With the knowledge of the differences, youll be able to draw a comparison between R12 vs R134a efficiency. I could easily be over at least 2 - 3 ounces over on the oil. Its chemical symbol is CCl2F2. Rules governing changing from the former to the latter differ between countries. So you could likely put off buying those new hoses just a bit longer if you wanted. I don't know where it is getting the switch off command, or why the vent temp drops steadily. Its chemical symbol is CCl2F2. It's actually a reaction with chlorine in the mineral oil that may have been absorbed and leftover from the old R-12. a 50f delta across the condensor is good, but I suspect that is an idle reading. How an A/C Expansion Valve Works. A/C Expansion Valve Replacement Cost. This kit comes complete with Expansion valve, o-ring kit, and 1ft. Table 1 summarizes the technical characteristics of three potential R134a alternatives. Trinary Pressure Switch $ 39.99. Until 1995, most cars with air conditioning used R-12 Freon refrigerant which has shown to have an environmental impact. The cost of recharging the air conditioner is between $150 to $500. You'll get marginally better performance out of the change as the expansion valve is matches the refrigerant characteristics. Crap! -------------------------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. Next I'll jumper the aux fan. 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. 1.5 ounces - hmmm. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. Debug the condensor (I am a computer nerd after all!)3. R134a has the chemical formula CF3CH2F and is known as tetrafluoroethane. R134a. R134a is called tetrafluoroethane (HFC). ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. Plus, not releasing the chemical into the air is morally justifiable. It cycles on off in med (or low for that matter)Gotta tell ya. 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. Mine was 61, so the system is not working as it is supposed to. Disconnect the two hose lines to the compressor, protect the ends from getting dirty. Trinary Pressure Switch quantity. What is a T/C?4. Most of all the differences gravitate to longevity, functionality, and safety. And I lied about the compressor switches on this car - there are 2 switches on the drier - a temp and a pressure switch. Yes it will work with either Refrigerant! In a car ac, using this type of freon 20 years ago was difficult. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. As noted, measure up front as best as you can to get as close to the aftermarket dim. 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. Its chemical symbol is CH2FCF3. The primary function of the design engineer is to make things difficult for the fabricator and impossible for the serviceman. Then again, there are two different expansion valves. The approval is very legal one, governed by the U.S. EPA. Above this temperature, the saturation pressure of R134a is higher than that of R12; below, it is lower. #13. As for R134a and R1234yf, theres no room for conversion. R12 Expansion Valve = 201 830 06 84 R134A Expansion Valve = 201 830 04 84 Is there a difference after all? Low refrigerating effect per pound: In comparison to other refrigerants, the refrigerating effect of R12 per pound is low. You may need to adjust the valve in a bit to get desired superheat. The difference really shows up on the high side. difference between r12 and r134a expansion valve. Are r12 and r134 fittings different? and feeds it through an expansion valve. Some compressor manufacturers or OEMs suggest PAG type oil for R134a. In more serious, it could result in cardiac irregularities or death. When the sensor detects the refrigerant leak the sniffers lights glow and the sniffer makes a noise. It is common for eurocar threads to go multiple pages, and as Nick points out - sometimes cool is all you will ever get. The original CFC expansion valve used for R12 needs to be replaced with an HFC one for 134a to feed the evaporator correctly. Have a look in the FAQ Section, and look for "Fan clutches & testing them". 4 Stars & Up & Up; 3 Stars & Up & Up; 2 Stars & Up . 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 old compressor used R12 and the new unit will be R134a. R12 contains a chemical called chlorine that destroys the ozone layer, thereby causing potential environmental risk. difference between r12 and r134a expansion valvewarning signs for a deteriorating patient with covid 19 infection 2022.07.03 18:36 18:36 "Jerky Locker" LMAO I am using that one in the future!Florida = BUGS! Inasmuch as R134a has a global warming potential thats over 1000 times more threatening than carbon dioxide, its better than R12. 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. Just had knee surgery yesterday, so I"M not exactly hopping around too well. 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. Fitting a PF condensor is not rocket science, but it requires some planning. At this point it is time to make an appointment with the a/c shop. The expansion valve(Tx) is in the car at the inlet line to the evaporator with compressors you best get advice from an ac specialist shop as the differences could be the gas that it pumps some systems use R12 and others use R134a or later gas yes R1234yf Freon gas can be replaced by R134a; the newer systems were designed with this in mind so no, there will be no damage to the compressor but some time in . There is a lot of differences between the R12 and the R134a fittings, you can't mistake them. R134a refrigerant fittings are different size. The exact amount will vary with each car. 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. If you have a perfectly operating system using R12 you do not have to drop what you are doing and convert to R134a. difference between r12 and r134a expansion valve. bokoen1 hoi4 the great purge / meryl and maks dancing with the stars / difference between r12 and r134a expansion valve. 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). A discussion of the relationship between valve capacities and superheat set-tings can be found in Bulletin 10-9. It is perhaps possible to locate a unit with a company that purchases close out or distressed merchandise. 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. Please enter a password for your user account. I don't want to be chasing ghosts. 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. . 3) A/C Compressor Always On. 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. I'm curiousSo there is work to do, ie performance should be able to be improved. Is there a difference between a R134a expansion valve and an R12 TXV? maintain the A/C of older cars. In practice this means that the car can overheat and the aux fan will stay off! The money you will save by will pay for the R12. Nick, I hear you - there maybe nothing to do here. R134a compressors are substituted as new to retrofit the R12 system compressor part numbers with different height sealing washers. The current expansion valve is FF - 1/4 - C. Is it neccesary to replace this valve? The only difference I can imagine would be the recharge connection. Stopleak is also risky. El juny de 2017, el mateix grup va decidir crear un web deDoctor Who amb el mateix objectiu. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. 10,000BTU conduction heating? A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . compressor, condenser, evaporator and expansion valve are specifically designed for use with R134a. Anyone know what happens when an R12 expansion valve is used in a system charged with R134A? Condensers designed to release greater amounts of heat help to expel the greater amount of heat which R134a removes from the cars interior. The crossover point is approximately at 64F. 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. I cleaned the evap as best I could, if that is what you are getting at. Are you sure you have an R4? 5. I recommend replacing the expansion valve when you do the swap. If you have 10 ounces of oil in the system, that is contributing to the poor performance as well. All pre-97 XJs use systems with the same basic operating principle, although the parts do change a bit. 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. Mark Baker R-401b is the mixture by weight of 61% R22, 11% R-152a and 28% of R-124. R12, on the other hand, has an ozone depletion potential of 1, implying that it can damage the ozone layer. By: james smith underoath; Comments: 0 . Als nostres webs oferimOne Piece,Doctor Who,Torchwood, El Detectiu ConaniSlam Dunkdoblats en catal. What is a good differential? Put a relay on the compressor clutch to the aux fan (I like that idea - makes a lot of sense)How does that sound? A comparison between R12 vs. R134a temperature will show that R12 has a higher temperature than R134a. The catalytic converter is an essential component of your car's emission system that helps save the environment from harmful emissions. Different correction factors are applied to other refrigerants. It won't be optimal, though. Unfortunately, the oil only mixes with the refrigerant as a liquid. 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. R12 was once used in many air conditioning units as a refrigerant or cooling agent. . . R134a systems operate at higher discharge-side pressures than R12, which can cause compressor seals to leak. 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. 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. However, it was found to be a very bad gas for the environment. 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. The chemical composition of R12 and R134a differ. Since the hose is the stock hose, you cannot tell what refrigerant is inside. 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. It won't be optimal, though. 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. 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. There are three different refrigerants officially sanctioned by the EPA for automotive usage: r-12, r-. With R-12, 30 is 28.4psi and 40 is 36.9psi, for a difference of 8.5psi. You should keep in mind that recharging your air conditioner improperly could result in more serious damage. By after changing just about everything, he got what was termed, satisfactory cooling. After the optimum refrigerant charge is determined the car should be test driven to check for performance of the system. Its among the greenhouse gases and will keep adding the current problem of heat not leaving the earths atmosphere. 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. I've got a ball valve I'm going to put in the coolant line before the coolant goes through the firewall to the core. You will be fine with a 134a-compatible TXV running R12. This is due to many facts: R134a refrigerant is about 10% less efficient in moving heat than R12! absorb by the evaporator to insure all liquid refrigerant entering the evaporator. I put one in my old daily driver '79 Chevy tank (r-12), and it really made a difference. This works when the R12 charge specification is listed in pounds. Before R12 was replaced with R134a in 1995, it was mostly used in trucks and cars. Look at where the lines will end up. The aux fan seems to be working fine - it switches on occassionally. Besides R134a there are some other refrigerants that are approved to replace R12 and there is a long list of refrigerants that are not approved. GWP is a measurement of Greenhouse Gases and their effect on Global Warming. I'll put the relay on for that. ~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446. This refers to BTU's (heat) moved per pound of refrigerant moved. Some 1993 and older R12 systems aren't as 'compatible' as you'd think to switch over. However, if it is taken close to a fire flame or any electrical heating element, it disintegrates into toxic products. You can also check the Aux fan in your case. Pray I can let some oil out of the compressor without losing my precious R12. Biggest you can fit in there is best. is good, then I should be looking elsewhere? 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. Further production of R12 was banned in some developed countries by the Montreal Protocol because of its harsh effect on the ozone layer. 4.R404A R134a increased mass transfer resistance to reduce the transmission chamber heat coefficient, while R507 heat transfer coefficient is higher than R404A. Carefully study the chart and compare the following: To a large extent, the choice is up to you. What is usually sniffed are all the connections in the system: hoses and compressor, condenser, drier, expansion valve and evaporator fittings. Automotive Replacement Expansion Valves & Parts; Industrial & Scientific; Customer Reviews. 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. The MB chart shows 360 psi with R12 in some conditions. 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.