Took me a while to figure that one out, and how to say that. Then I'll put the ball valve in on the coolant and test it and see what we have. Heres R12 vs. R134a pressure chart. 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!) Consider using the newer valve, even with 134a stamped on the valve. Besides, R134a refrigerant was manufactured after R12 was banned to help reduce the harshness of the old chemical (R12) on the ozone layer. Hmmmm. The old compressor used R12 and the new unit will be R134a. Still, I have some simple green, so may as well give it a go. I think so. That's a lot isn't it? 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. We've updated our forums!Click here to visit the new forum, Year: 1991Make: Jaguar Model: XJ6Engine Size: 4.0. This works when the R12 charge specification is listed in pounds. The primary function of the design engineer is to make things difficult for the fabricator and impossible for the serviceman. 05-25-2017 02:14 AM. 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. It is a haloalkane and hydrofluorocarbon (HFC) refrigerant that has thermodynamic properties, potential global warming for one hundred years, and insignificant ozone depletion. Please enter a password for your user account. Lasers don't do well on vent temps, a stick thermometer is better in that application. 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. You may need to adjust the valve in a bit to get desired superheat. 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. Flushed, vacuumed etc. The value of carbon dioxide is 1. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . . I have some experience with auto a/c but not too much. R134a. difference between r12 and r134a expansion valve. Right now you know you have a bit too much, but with a CR4P compressor this is an insurance policy. This is because R134a. Usually, mechanics charge around $200 for conversion. Ensure you contact a professional mechanic to do the work for you so you dont end up incurring more costs for yourself. 4) Inconsistent Airflow. This drop can affect energy consumption since the plant will operate for a longer period or a larger plant will have to be installed. To prevent refrigerant loss you should consider replacing your old hose lines with barrier type hose. difference between r12 and r134a expansion valve . Very nice! Swapping the components isnt a herculean task, but recharging the AC is a challenge. R12 was once used in many air conditioning units as a refrigerant or cooling agent. R134a refrigerant fittings are different size. A thermostatic expansion valve (TXV) (see Figure 1) is a refrigeration and air conditioning throttling device that controls the amount of refrigerant liquid injected into a system's evaporatorbased on the evaporator outlet temperature and pressurecalled the superheat. We say generally because the vehicle manufacturer may have a formula already worked out for the R134a conversion process. Its among the greenhouse gases and will keep adding the current problem of heat not leaving the earths atmosphere. 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. A York oil capacity is listed as "6.5 to 9.6 ounces". We mention using ester type refrigerant oil. I don't think it has any air dams or seals, I'll check to make sure. Typically 5 to 6 ounces of a/c oil is adequate but this may vary depending upon the car. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. Is there a graph? 5. 5) A/C System Failure. Its highest value is 1. PaulJerky King -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a. Stability: RR12 doesnt disintegrate even under extreme operating conditions. An extra half ounce? How about evacing 1 pound of refrig from the system, and then putting 1 lb of pure R12 back in? The crossover point is approximately at 64F. 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. As an example, let's say the R12 charge specification is listed at 2 lbs. Remember, being aluminum, they lower the temps better, and do not pass off as much heat to the radiator, which then makes it's job easier and lowers underhood temps (besides lowering vent temps inside the car). 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. A/C Expansion Valve Replacement Cost. In cases such as this, the required capacity value of the expansion valve with R134a is reduced by 30% (correction factor 1.42). The system will be checked for gross leaks while under vacuum. On the other hand, R12 has a global warming potential of 10,910. This means that it has a high potential of causing depletion to the ozone layer. Yep, definately not a meat locker. Is that why expansion valves are specific to R12 or R134A? The oil is spread all over your system when it is at rest. If you you dont have the free time to play then you are better off to pay a technician. We sometimes use a relay switched from the compressor clutch to run fans. What is usually sniffed are all the connections in the system: hoses and compressor, condenser, drier, expansion valve and evaporator fittings. The only difference I can imagine would be the recharge connection. Condensers designed to release greater amounts of heat help to expel the greater amount of heat which R134a removes from the cars interior. Debug the condensor (I am a computer nerd after all!)3. I put in a new (not reman) compressor (R4 I believe it is) in my merc 240D, new drier, new expansion valve, new o-rings, nylog. If the system was upgraded by a professional it should have an upgrade sticker. Since the hose is the stock hose, you cannot tell what refrigerant is inside. As R134A refrigerant has different operating characteristics and pressures this valve is not necesssry. Also, R134a cylinders are light-blue in color. Formula: (R12 Charge Specification x 0.9) - 0.25 lbs. Generally this works well for the whole system. and recharged with mineral oil and 2.2 lbs R12. 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. I had a 1991 BMW switched to 134a by just changing the low pressure charging valve, flushing and refilling with 134 (maybe with 10% . With tube & fin condensors in MVAC applications there is never "too much" airflow. Plus, not releasing the chemical into the air is morally justifiable. A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . 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. The system has been previously converted to R-134a. I'm having the same concern. VerticalScope Inc. All Rights Reserved. The common problem when converting from R12 to R134a is lack of knowledge or equipment. R 134A is designed for the high demands of an automobile AC and cannot be used on refrigerators due to pressure differences. 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. If the water valve is not closing all the way you will have re-heating of the cabin air.The cabin blower was not exactly a powerhouse - it was rated at 200w. In most cases, the systems used have varied components, designs, and service ports. 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. Fitting a PF condensor is not rocket science, but it requires some planning. 2001-2023 Griffiths Technical Inc. All Rights Reserved. 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. So I probably put the highest suggested amount in to be safe. Rules governing changing from the former to the latter differ between countries. We consider the the various types alternative refrigerants that are illegal or not approved to be in two sectors: non-flammables and flammables. 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. 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 sticker typically has a place to note the amount of refrigerant used, the type of oil and amount of oil, the technicians sign off or name and the date of the conversion. However, theyre still used in older plants, systems, and the automotive industry. Therefore, the higher the factor of the chemical (compound), the greater its effect on global warming. The safe high side pressures are determined with a PT (pressures and temperatures) chart. Generally, the new amount is 75-85% of the quantity advised by the manufacturer. Then at least I'd know really where I am on it. It won't be optimal, though. 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 . Inhalation of vapor: Inhaling a large amount of R134a vapor can lead to drowsiness, temporary nervous system depression, and lethargy. 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. Attach the R134a charge port adaptors, there are two types.. one of which you need to remove the old R12 valve cores. 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. Energy usage: R134a is less efficient in cooling compared to 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." If you have a perfectly operating system using R12 you do not have to drop what you are doing and convert to R134a. . 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. The flammables have hydrocarbons. Yes, I don't trust the heater valve either. Minor adjustments to the expansion valve and other controls may be necessary for some plans. You will be fine with a 134a-compatible TXV running R12. This refers to BTU's (heat) moved per pound of refrigerant moved. 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. R134a is NOT less efficient than R12 Actually R134a is more efficient. We chose to use 5-6 ounces of oil to be on the safe side: 3-4 ounces for the compressor, 1 oz of oil for the drier and another ounce of oil for system losses. To ensure the right charge, you must fill the new system with between 75 and 85% of the factory-set capacity for optimal cooling. |. Components Coils, Heaters, Motors, etc. A capacity curve is shown in figure 2 for relative capacity of R134a vs. R12 for evaporating temperatures from 0F to 50F. R12 is highly destructive to the earths ozone layer. 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. Get to the point where I can walk without crutches2. This may be the source of your oil confusion. 4 Stars & Up & Up; 3 Stars & Up & Up; 2 Stars & Up . The pressure at low temperatures is nearly the same between 12 and 134a. You should keep in mind that recharging your air conditioner improperly could result in more serious damage. Make sure visiually that no large gaps exist that would allow the air to bypass the condensor on the way to the radiator.B. Quick View. R12 is heavier than R134a and has smaller molecules. Participate in over 40 different forums and search/browse from nearly 3 million posts. 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. B. 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. Use a drop light in the engine bay, and check the air path from the front of the car at night. look at the difference! 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. He used thermostatic expansion valve and Capillary tube for analysis with R12. R134a has a smaller molecule than R12 so R134a will leak out sooner than R12. Thread starter goldNSX; Start date 1 August 2009; Tagged . R1234yf. A final difference is that most (though not all) R-1234yf cars will have a Suction Line Heat Exchanger. This kit comes complete with Expansion valve, o-ring kit, and 1ft. Trinary Pressure Switch $ 39.99. Its chemical symbol is CCl2F2. When the sensor detects the refrigerant leak the sniffers lights glow and the sniffer makes a noise. At 40, it is 35psi, which is a difference of 8.9psi. Most importantly, the oil used in the plant must always be compatible with the refrigerant used. 3 ounces? Table 1 summarizes the technical characteristics of three potential R134a alternatives. The general practice of charging the system with 15% less refrigerant adds to the thermal deficiency of R134a. Flush with a garden hose - do not use a high pressure washer - you can bend the fins flat & damage the condensor.B. Bad Car A/C Expansion Valve Symptoms. 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 money you will save by will pay for the R12. In addition, R134a refrigerants are not only used in auto air conditioners, they can be used in freezers, aerosol cans, and refrigerators. 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. Theres no problem with using R134a in a home air conditioning system because it is a hydrofluorocarbon that doesnt cause environmental harm. R12 is used in several applications like low temperature, medium temperature, and high-temperature applications. How is 1234yf different from . Also, it can be used with all types of compressors. R12 systems used mineral oil, but unfortunately mineral oil doesn't dissolve in R134a. leading to corrosion of expansion valves, capillary tube plugging, and compressor bearing . The higher the ambient temperature the higher the high side pressure. Thomas Jefferson, Thanks,OK, I'm starting to feel a little better about it. El juny de 2017, el mateix grup va decidir crear un web deDoctor Who amb el mateix objectiu. Replace the drier with a drier that has a desiccant that is R134a compatible, use new R134a o-rings. But as there's not a big difference, people say you can suffice with either. _____ 2012 E350 2006 Callaway SC560 . After the system has been tested out it should be checked for leaks. The evap is hard to get at. Statisicaly your friend was lucky. Its chemical symbol is CH2FCF3. Its cylinders are colored white. R134a vs R12 refrigerant? 5. 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. Stay home and grill your own steaks and stir your own martini. The whole trick is to sit there in those steam boxes and not perspire, it's vulgar to perspire when driving on public roads.If you want esteem, drive an MB, if you want comfort with 60*F interiors in a 125*F environment, get a Caddy. 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. Do a pre-inspection and then Evacuate (vacuum down) the system, the longer the evacuation the better but there is a point of diminishing return, 2-3 hours is generally very good. The bad thing is I don't know what to do about it. 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. The difference between the two is about 10,000 btu/h. 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. 1) Look Here at the available sizes of PF condensors.2) Go look at your vehicle's condensor & mounting. Though you can purchase 12 or 16 ounce cans of R134a from local retailers it is very difficult to measure out the correct amount into your system. A. Pressure/temperature table for R12, R134a, and R513A is shown in Figure 1. . R12, on the other hand, is called chlorofluorocarbon (CFC). With the oil leaking out and being told all sorts of things about how these compressors don't have a sump etc, I wanted to be on the safe side. R134a and R12 are among the most popular types of refrigerants. Don't like the sound of custom parallel condensor. If you have a York, and it is equipped with service valves, you can check & adjust the oil level without discharging the system. As per their results . (The .133 is the 300D Turbo).So, what does your compressor look like?B. 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. Als nostres webs oferimOne Piece,Doctor Who,Torchwood, El Detectiu ConaniSlam Dunkdoblats en catal. The OEM spec is 2300 rpm @ 12.6v (engine stopped fully charged battery). The cost of recharging the air conditioner is between $150 to $500. (On firewall where A/C lines go into cab.) 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. 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. In a car ac, using this type of freon 20 years ago was difficult. Some compressor manufacturers or OEMs suggest PAG type oil for R134a. To bless the system the technician should attach a R134a sticker somewhere in the engine compartment to note the car is using R134a. Using R134a requires that Polyolester (POE) lubricant must be used in the compressor. -------------------------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. 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. Replacement expansion valve for R134a or R12 A/C refrigerants, with O-ring connections. All fans must work at 100% of the OEM rating. Recomanem consultar les pgines web de Xarxa Catal per veure tota la nostra oferta. american sniper longest shot; how to adjust sunsetter awning arms; pastor jeremy roberts texas. My turn to LOL - greasiesel! It cycles on off in med (or low for that matter)Gotta tell ya. . El maig de 2016, un grup damics van crear un lloc web deOne Piece amb lobjectiu doferir la srie doblada en catal de forma gratuta i crear una comunitat que inclogus informaci, notcies i ms. They might say for instance, add 3-4 oz of oil to the compressor, 1 oz of oil for when you replace a drier, 2 oz oil for the evaporator and so on. Is there more info needed?THanks -------------------------1983 Mercedes 240D on R12 and WVO!1192 Mercedes 300D 2.5 R134a1993 Toyota Pickup converted to R134a, Paul:I had to dig a bit deeper - MB made several running changes in the 1983 123'sThere are actually 4 different circuit diagrams for the A/C system that year - just for your 123.123 I found the R4 reference, and it should have 170 Ml of oil in the system.Your aux fan should run at the ambients you listed. Paul:It is never a waste of my time to chat with someone that understands the problem, and wants to fix it. 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 original expansion valves work very well with R134a. In the automotive world, the replacement for R12 was R134a. Pray I can let some oil out of the compressor without losing my precious R12.

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