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1234YF FREON

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bantar Community Regular

bantar

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We're still waiting.  We only turned away 6 jobs last year.   When it makes sense, I'm ready to buy the machine.   It might be this year, and if not, definitely next year.

Do you have a nitrogen setup (gas and nitrogen leak detector) to pressure test the AC systems now?   For us, we could afford to recharge a system if it left with an undetected pressure leak (aka return for a dye check).   With the cost of 1224yf, we will need a different model of operation.   We need to find the pressure leaks via nitrogen and bill for the refrigerant each time it is installed.   We don't charge by the oz today.   AC jobs with 1234yf are going to double or more on cost. 

I'm interested to hear how others are dealing with 1234yf pressure leak detections.   I'm expecting to buy both the machine and nitrogen setup at the same time.

bantar Community Regular

bantar

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There should be nothing illegal with the use of nitrogen.  (Non-auto) HVAC professionals flood their systems with nitrogen when the braze the lines.  They too utilize multiple methods of leak testing. 

I've been looking at the testing aspect.   What is clear is that pressure leaks are costly.   I've found a few primary solutions:

1) Nitrogen Testing with an ultrasonic leak detector

2) Nitrogen Testing with a Leak Down Test gauge set:

  • NOTE:  Dry Nitrogen is recommended
  • Digital Leakdown Test with Software pressure compensation due to temperature changes.  Very accurate.  https://smile.amazon.com/Fieldpiece-SM380V-3-Port-Refrigerant-Manifold/dp/B07QJ7P63Z
  • See button Test Tightness - Timed leakdown test with digital readout.  Can detect very small leaks.
  • NOTE:  Same test can be done with a regular manifold test for large and maybe medium leaks, but there's no way to find very small leaks, as you don't have the detailed resolution in your gauge set.
  • Nice thing about this test is that is independent of your RRR machine.  Testing is 30-60 minutes or overnight.

3) Hydrogen Tracer Gas Leak Detection - 5% Hydrogen / 95% Nitrogen testing (Mixed gas)

  • This test model relies on being able to more easily detect escaping hydrogen.
  • Called Tracer Gas or sometimes Forming Gas
  • Much data here:  https://schoonoverinc.com/hydrogen-leak-detection/
  • Testers seem to be expensive.
  • This method seems to be popular in Europe.

4) Combo Leak Detection:   Nitrogen followed by Tracer Gas

  • Looks like Robinair has a solution:   Leak down test with Nitrogen, followed by Sniffer testing with Tracer gas.
  • ACS Nitrogen Kit EN 86447 - can't find it, so what's in it?
  • Tracer Gas Leak Detector:   https://www.amazon.com/Robinair-Tracer-Leak-Detector-Service/dp/B07V5WS9R9   about $700
  • However, watching this video: 
  • They use Nitrogen to determine if a leak exists, then tracer gas to locate the source.  I'm going to guess that the tracer gas is more expensive than Nitrogen.
  • The disadvantage to this system is that your RRR machine is now tied up for much longer.  Already 1234yf is way slower than 134a.   Add in this new step and it could tie up the machine for half a day or more.
  • I'm unable to locate this test setup here in the US, but have not called Robinair either.  

5) 1234yf Gas Leak Detection

Nitrogen Setup:

  • For nitrogen testing, you need a cylinder, a pressure regulator and gauges.  
  • You can buy a ready made kit such as:   https://www.amazon.com/CPS-Products-CPSNITROKITG-Nitrogen-Regulator/dp/B009M9WKO4
  • Nitrogen cylinder pressures are about 2000 PSI, so it can definitely pressurize the Auto AC system.   A high quality gauge set and regulator are necessary to not blow holes in the AC system.
  • On R123a cars, nitrogen pressure testing is done at 175-200 PSI.  Exceeding 200 PSI, you can create new problems that didn't exist before.
  • On R1234yf - 200 PSI should still be ok.
  • We keep talking about Dry Nitrogen, however, our RRR evac process should boil out any moisture introduced by using regular nitrogen.  It appears that not introducing moisture is a better first step.   I don't think it matters, but if the costs are similar, Dry sure seems a better first step.

Please be aware, I convey all of this information without any credibility myself.  I much prefer to seek out experts and repeat what they are doing.  Finding a true expert is difficult, but internet data is plentiful.  I'm sharing what I've found with the hope that it helps others recognize the need for a solution and find a way to remain profitable with the very expensive 1234yf gas.

 

  • Like 1
  • 2 weeks later...
bantar Community Regular

bantar

Posted
Posted

Well, I've done a bit more digging.  I had my tool guy reach out to RobinAir to check on those items in the video above.  They only have one machine in the US that supports this connection and it's not a popular item.  Further, the H2N2 Forming gas is also readily available in Europe, in disposable cans, but less so here.   You can purchase it in a 300 CCF cylinder from AirGas as a special order.  This size would be an Inheritable supply.

However, I overlooked a 6th method for leak detection:

6) Shop Air and Soapy Water

  • 150 PSI of shop air and soapy water looking for bubbles
  • However, you are introducing moisture into the system. Is this a best practice?   Is this a bad practice?  
  • It's a free test.  Instructions here:

Stepping back from tooling, the question is what problem needs to be solved?

  • Some leaks are bi-directional and can be found with either a vacuum test or a pressure test
  • Some leaks will pass the vacuum test, but will fail under pressure
  • We want to find both leaks.  Ideally, we should run both types of leak tests in an AC Service.
  • The low cost of R134a, the availability of dye and the vacuum leak test of the RRR machine allows for a reduction in overall testing.
    • In other words, we can skip the pressure test.  How many leaks will only be caught with this test method?   This reduces the cycle time and labor involved to the customer, keeping the service prices reasonable and allows the shop to remain profitable.
    • R134a, $3/lb with dye finds pressure leaks affordably. Customer drives away and returns for a complimentary leak check.   Our material cost is about $5 and the labor cost is near $0 as the car leaks and dye shows where it is. 
  • The higher cost of R1234yf begs the question, do we add in the pressure testing step to every service?
    • This costs the shop extra labor that will need to be billed to the customer.  Service pricing increases.
    • R1234yf pricing is about $60/lb.  So, our material cost is about $100.   Is this an acceptable shop cost for leak detection? 
      • Should this cost be passed on to the customer? 
      • Technically, it is only a burden to them if we didn't find the leak with the RRR machine.
    • The RRR machine only does a partial R1234yf charge and stops for you to execute a Manual Leak Test using a handheld scanner
      • Since this step exists, one can ask if it is an acceptable leak test?  
      • The ability to find a leak is dependent on the quality of the tester and the skills of the technician in operating the unit and the leak size.
      • At this point, you don't know if you have a leak, so you are scanning for a potential leak.  
      • How much time do you invest in searching for a non-existent leak?   No leak is good.  Would an impatient technician pencil-whip this test?
      • Who loses money if it's not found with this type of testing?
    • Let's say we detect a leak, how do we find it?
      • We need to inject a detectable agent.  At this time, it seems a partial charge of R1234yf is a viable solution.
      • RRR machine comes into play again
      • Back and forth equipment setups increases the overall time and labor costs for this job

Again, I'm approaching this from a HOW TO PROVIDE THIS SERVICE PROFITABLY perspective.    These are my thoughts as of today...

  • Equipment exists that will definitively tell you if you have a leak.
    • This lowers my risk of both costs or hits to goodwill
  • R1234yf service cost is going to be higher everywhere.
    • Machines are more expensive due to the purity testing function
    • Cycle times are longer for the same job (machines are slower)
    • Refrigerant is currently more expensive.
    • Will the customer notice adding in an expense for leak testing?   They'll already be in sticker shock.
  • Makes sense to burden in a material and labor charge for pressure leak testing now
    • It provides a more consistent pricing to the customer vs letting them pay for lost refrigerant
    • Probably .5 - 1.0 hours
    • Fieldpiece Digital Manifold with a Nitrogen setup will give a definitive leak result. 
      • I like this because you can read the answer.
      • I like it because it frees up the RRR machine for overlapping jobs (only an optimist would go here)
    • Plan to use my IR Leak Detector, but have to inject R1234YF into the system
  • If a leak is found, then additional labor to find the leak, fix it and another leak test to confirm
  • I do not intend to equip for handling contaminanted (refrigerant) vehicles and recycling thereof. 

I'm thinking out loud.   It would be good to hear from someone that practical experience.   I've talked to a few folks that are just using the RRR machine with a No-Warranty clause on the refrigerant.    I'm not expecting that this level of leak testing will be the most popular practice in the US.   It's all fine and dandy until it's not and somebody will be eating lost refrigerant cost.

  • Like 2

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