R12 is dichlorodifluoromethane, and, yes, is smaller than R134a....but...
I’m pretty sure R134a is 1,1,1,2-tetrafluoroethane (you denote it as R134) rather than 1,1,2,2-tetrafluoroethane...OK, OK, picky as they are isomers and R134a probably has some ratio of both...I’m a polymer chemist, so not too familiar with R134a other than I know it’s chemical composition...
And I will agree with you about the ‘teeny molecule that can pass through metals’ comment...that’s not correct...now, heat (heat transfer) can pass through metals readily, perhaps he was referring to the cooling that occurs when R134a goes from the liquid phase to the gaseous phase? But that’s true of all refrigerants as that’s how it works...
Or, perhaps personal experience with refrigerant systems leaking? That always happens as they are not perfectly sealed systems...would be nice, but that’s generally not economically feasible...
Correct,
R134a is 1,1,1,2 tetrafluoro-ethane.
R134 is 1,1,2,2 tetrafluoro-ethane
the letters designate the level of imbalance.
No letter means the molecule is balanced.
a means one level of imbalance.
b means two..
The numbering scheme tells you the molecular structure. It was a formulation developed by DuPont (allegedly). You add 90 to the number, and that gives you the number of Carbons, Hydrogens and Fluorines. The balance being Chlorines.
If there is a number in the thousands place, that is the number of double bonds.
So R134 + 90 = 224. So two Carbons, two Hydrogens and 4 Fluorines. Since the molecule is fully specified, there are no Chlorines.
No, I had my designation correct. Lets see if I can put spacers in so that my molecules don’t collapse this time.
R134
....H. H
F-C-C-F
....F. F
R134a
....F. H
F-C-C-F
....F. H
Depending on what grade of R134a you are buying, there will be some level of R134 in it. But that level is in the 0 to 1,000 ppm range. Not worth writing home about.
Yes, the regulations are making a huge mess out of the Refrigeration industry.
The new (global warming friendly refrigerant) is R1234yf... Here is an interesting article on that by Mercedes Benz. Watch a nice hew car go up in smoke.
Roflol. Glad I wasn’t in it.
quote
“ Cars may explode in crashes if EU forces firms to fit ‘highly flammable’ green coolant, warns Mercedes
Mercedes say the ‘climate-friendly’ chemical is highly flammable
Brussels and the coolant’s producers deny the suggestion
By RAY MASSEY
PUBLISHED: 13:15 EST, 15 February 2013 | UPDATED: 13:31 EST, 16 February 2013
New cars sold in Britain and Europe risk catching fire and exploding in a crash because of EU rules to impose a controversial ‘green’ air-conditioning coolant from the start of this year, German car giant Mercedes-Benz has warned.
The luxury car-maker says the new ‘climate-friendly’ air-con chemical is ‘highly flammable’, poisonous and poses a danger both to occupants and rescue services – and German government officials now agree.
Mercedes-Benz is refusing to put the controversial new gas refrigerant into its latest vehicles, sparking a major confrontation with Brussels and the firms who make it - both of whom deny any safety risks.
Wheels on fire: Mercedes carried out their own tests on the coolants
Wheels on fire: Mercedes carried out their own tests on the coolants
Today, Mercedes-Benz and its parent company Daimler received backing from Germany’s Federal Environment Agency UBA.
It asked the EU to ‘compromise’ by granting them and other car-makers – including Volkswagen and Audi - an extension from the mandatory rules until 2015 if they agree to introduce an alternative green refrigerant based on carbon dioxide, which experts say is safer because it doesn’t burn.
If Daimler is correct, around 2 million new cars sold in the UK each year are potentially at risk. Photographs from the firm’s own simulated crash tests on cars showed that a mix of the refrigerant and air-conditioning compressor oil released under a car’s hood could ignite a heated engine.
This would mainly be a risk if the car crashes, but it is also possible if the coolant leaks for any other reason.
The row centres on the new coolant with the codename ‘R1234yf’ which Daimler argues can start a fire in the car and release toxic hydrogen fluoride gas. It is the replacement for the long-time industry standard, which EU legislators in Brussels have ordered to be phased out from January because of concerns about greenhouse gases.
The new ‘green’ refrigerant is produced by US giant Honeywell and is currently the only one if its kind that meets new EU climate guidelines. The firm denies categorically that there is any safety risk.
Car makers are supposed to phase in the change from the start of this year, but by 2017 every single one of the estimated 14 million a year air-conditioned vehicles that rolls off assembly lines for sale in Europe will be filled with about £43 worth of the new coolant. This will not include the million Mercedes-Benz’s built each year, of which 90,000 are sold in the UK.
Urging the EU to compromise, Jochen Flasbarth, president of Germany’s Federal Environment Agency UBA said: ‘We have been warning about the dangers (of HF0-1234yf) for years. Daimler’s internal tests proved not only that our own fears were justified but also that we may even have underestimated the risks.’
But he added: ‘It’s just not possible to switch to a CO2-based system within six months or even a year, though, so I would propose giving carmakers until the end of 2015 to make the switch.’
Mr Flasbarth noted:’If you switch to CO2 then you reduce your global warming potential by 75 per cent over HFO-1234yf, so I think that justifies permitting a longer transition time for those carmakers that commit to the switch,’
Earlier this month, BMW joined Daimler and Volkswagen’s Audi in resigning from an industry research group looking into the safety of HFO-1234yf, due to concerns over the scientific thoroughness of the investigation.
Mercedes officials said they were horrified by the results of the coolant leak tests
Mercedes-Benz executives said they watched in horror when engineers at a test-track in Sindelfingen in Germany simulated a leak in the air-conditioning line of a Mercedes B-Class tourer using the new coolant.
After releasing a fine mixture of the refrigerant and air-conditioning compressor oil which sprayed across the car’s turbo-charged 1.6 litre engine, they watched it ignite in ‘a ball of fire’ before their eyes.
The substance caught fire as soon as it hit the hot surface, releasing a toxic, corrosive gas as it burned. The car’s windshield turned milky white as lethal hydrogen fluoride began eating its way into the glass, said the firm.
Stefan Geyer, a senior Daimler engineer who ran the tests said: ‘We were frozen in shock, I am not going to deny it.’
A Mercedes-Benz source said: ‘In over half the tests, a significant fire occurred, which could endanger the lives of passengers and rescue teams.
‘It doesn’t explode like in the movies. But there is a boom and a ball of fire.’
‘In over half the tests, a significant fire occurred, which could endanger the lives of passengers and rescue teams. It doesn’t explode like in the movies. But there is a boom and a ball of fire’
Mercedes source
Walter Pütz, director of vehicle certification and regulatory affairs at Mercedes-Benz Cars said: ‘The whole vehicle can catch fire and the burning refrigerant generates acutely poisonous hydrogen fluoride which poses a severe danger to both passengers and rescue workers.’
In sharp contrast, the existing refrigerant ‘was proved to be safe under identical testing conditions, he said.
Daimler said in a statement: ‘Due to the new findings of this study and the high safety demands at Mercedes-Benz, this chemical will not be used in its products.’
German carmaker Volkswagen has also announced it is looking at an alternative carbon-dioxide (CO2) based coolant to the new ‘green’ version.
But MEPs said parent company Daimler were putting cost-cutting ahead of climate change remedies – charges the firm denies.
Liberal MEP Chris Davies told European magazine EurActive that the firm was trying to ‘frustrate’ the directive’s ambitions: ‘Daimler are evil and I think their CEO should be summoned to the European parliament and humiliated.’
He said: ‘Daimler has apparently discovered that HFO-1234yf is flammable. Well so are petrol, oil and diesel. Of course it’s flammable if you shove a flame thrower under it, which is more or less the test that Daimler is said to have carried out.’
Honeywell today countered the safety fears by publishing a report from safety experts SAE International saying that their new air-con fluid ‘posed no greater threat than any other engine compartment fluids.’
It accused Mercedes-Benz of using ‘unrealistic’ and ‘extremely idealised’ testing conditions.
Honeywell vice president Terence Hahn said the report left no doubt that their refrigerant ‘is safe for automotive applications.’
A spokesman for Britain’s Society of Motor Manufacturers and Traders (SMMT) said it was taking seriously Mercedes-Benz’s concerns, adding: ‘At the forefront of all members thoughts is the safety of drivers and passengers in the vehicles they are putting on the market.
‘The additional research is welcome and members will be looking at the outcomes of that research closely.’
Paul Sanders, managing director Fluorines EMEAI, Honeywell said their new air conditioning refrigerant ‘has been proven to be a safe and effective replacement.’
‘It is already in use by the auto industry. It reduces the global warming impact of automotive refrigerants by 99.7 per cent.
‘Its adoption in cars today would have the greenhouse gas equivalent impact of removing more than 4 million cars from European roads.’
He added car-makers had six years to prepare to meet the requirements of the new directive and that ‘the vast majority of automakers have taken the necessary steps to comply’
He said Germany’s Federal Environment Agency (UBA) ‘only spreads misinformation’ and said using carbon-dioxide was ‘inefficient’ and had ‘short-comings’ adding:’It has higher emissions when both the air-conditioning system and efficiency of the engine are accounted for.’
Vauxhall, part of the giant General Motors, said it was pressing ahead with plans to introduce the new coolant in its new cars.
General Motors’ engineering manager for new refrigerants Curt Vincent told trade magazine Automotive News: ‘We did crash tests, computer simulations and thermal analysis and did not observe any safety problems at all.
‘Many have tried to repeat Daimler’s findings, but no one has come forward with anything that would indicate any concern.’