Excellent question for which I have no answer. I think you'll have to seek an expert like Al Gore on that one.

LOL!

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'98 E300 turbodiesel

Simple, R12.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Molecular Diffusion

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1981 300SD 512k OM603

Quote:

Originally Posted by kingdoc1 While we are on the subject of hydrocarbon and non-hydrocarbon refrigerants, would someone please answer this nagging question:

Alright guys let’s have a quick chemistry lesson to qualm all of these little theories.

Ozone is O3. It is created in the atmosphere when ultraviolet light reacts with oxygen molecules. This electrically charges them into o2

O2 + ( ultraviolet radiation 240 nm) → 2 O.

Oxygen doesn’t like being together with another oxygen atom and needs to be paired with something. This continues to become o3 in this process O + O2 → O3

O3 is also made by ionic breezes. It makes air crispy. This also explains why the air after thunderstorms is also crispy since the charged lightning bolt electrifies oxygen.

Ozone can be destroyed by a number of catalysts. Some of these are the hydroxyl radical (OH·), the nitric oxide radical (NO·) chlorine (Cl·) and bromine (Br·). All of these can come from natural or man made sources.

NOW

R12 is a CFC. CFC stands for Chlorofluorocarbon. A CFC is a relativly stable compound, however like oxygen when a CFC is struck by UV light the compoud breaks down into carbon, flourine, chlorine, and bromine.

POP QUIZ: What two elements of a CFC are also reactive to Ozone?
That’s right! Chlorine and bromine!

Now due to Earth’s atmophere being a constantly moving body of air. Chlorine and bromine eventually make there way up into the ozone layer by means of conduction (hot air rising). Although Chlorine and Bromine are in fact heavier then Oxygen they are spread gratly apart since they are in smaller quantities of oxygen. Think of it as a rock on a blanket spread out and people holding each end. Although the rock is pretty heavy, when every one pushes up on the rock it will give it enough momentum to go up.

The chlorine and bromine atoms then react with the O3 in a handful of reactions. One particular reaction is this:

Cl + O3 → ClO + O2

Oh no! The chlorine isn’t done with its devilish act yet! The ClO molecules continue their reign of terror on the ozone molecules:

ClO + O3 → Cl + 2 O2

Yarg!! It appears that r12 is not a great thing after all. This amongst other things has been steadly increasing those "made up" ozone holes

I hope this explanation helps. This has been researched and peer reviewed multiple times by many PhDs in many universities. Heck scientists have received Nobel prizes for this. There weren’t any politicians with the r134 lobby on this one.


Edit: R12 is also better than r134a.

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-Typos courtesy of my mobile phone.

Thanks Adam,
I was PROUD to make it through organic chemistry with a C Minus...
So I do not understand what you said..but it sounds good...
Thanks for explaining it ....
I do know that if it is inside my old AC system it is better than many other things....

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/showthread.php?t=156207&highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

I got through honors chem with a 76. The concepts aren't too hard. Many websites have a simplified concept of what is going on up there.

The real problem isn't r12 in automotive cooling systems, but aerosoels like deoderants, spray paint, etc. The montreal protocol wanted to limit and provide incentives for the development of better alternatives to CFCs in those areas. We can still buy r12 with a 609 license ;-)

Oh and there was another formula I forgot. I'll add it after work since I'm stuck on a blackberry :-/

__________________
-Typos courtesy of my mobile phone.

The difference between a 76 in honors chemistry...and a 70 in org chemistry for non science majors is a LOT... ( Sociology major here ).... LOL

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/showthread.php?t=156207&highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

My degree is in Electrical Engineering and this is one of those things that reminds me why I didn't study chemistry - BO RING!

Haha I'm going to have to disagree

Blowing stuff up > Electricuting myself

I took chemistry my sophomore year in high school. My college degree is in sound design and production

__________________
-Typos courtesy of my mobile phone.

You've got a point there when it comes to explosions. I have to tell what happened when I was a teenager.

A neighbor that I went to school with in the eighth grade was into chemistry, and I don't mean the pharmaceutical type. Today he is a chemist in one of the plants on the Texas coast.

Anyway when school was out for the summer he started mixing sulphur(as I recall) and sugar and we started feeding it to a huge red ant hill that was way out in the middle of a field. He said this would make a very weak gunpowder. We put a little of this concoction on that ant hill every single day all Summer long and on Labor Day he set a black powder fuse that led to it and we ran like He!!.

We were LUCKY! That thing made a crater you could lose a small car in. We had been running as hard as we could and we were a long distance from it, but we still got showered with dirt.

It scared the heck out of me, but it was definitely a thrill.

A few years later when I tossed a grenade in Army Basic Training, I was impressed, but at the same time a little disappointed by comparison.

For a living though, I'll still take controls over chemicals.

Thank You, that is the best actual explanation anyone has ever presented me with.

I have one question though, the last reaction showed yielded one Cl and two O molecules. Would those two O molecules then tend to unite with another and form more O3 like you explained at the beginning? Since we know among other things the ionization from lightning helps in the production of O3, are you saying that our use of CFC's depletes the O3 faster than it can be naturally created?

Yes

Like I said above, the concentration of chlorine, bromine, and other catalysts in the atmosphere is very light however our use of CFCs was in fact destroying ozone faster then it could be created. The final reaction basically released Chlorine back into its unstable state to start the reaction all over again destroying more O3 in the process.

It's all a vicious cycle and sadly one thing that we have done to ourselves in our ever industrialization of our world.

__________________
-Typos courtesy of my mobile phone.

Yes, it's all us pesky Texans that want our a/c to work in 108 degree heat. We are the destroyers of the world.

Hey, I saw yesterday some crazy temperatures in OREGON.... we can recruit more destroyers of the world from that now affected population...
Greenland is warming up and the native population is not too unhappy about it....they can now grow vegetable gardens...saw it on PBS...

__________________
1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/showthread.php?threadid=10414

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/showthread.php?t=156207&highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html