They're coming for your Air Conditioners!

[03Lightningrocks]

Here ya go wild bill... I'm no chemist but .... I can google foo with the best of them

Freon is actually a brand name for a class of compounds known that contain fluorine, and are gases at room temperature. If the compound also contains the halogens chlorine or bromine, these compounds are known ozone depleters (CFCs, HCFCs, and so on). The fluorine presents no challenge, but the other halogens do. == Free radical chain reactions == For instance, Freon R-12 is CCl2F2. These compounds were commonly used until it was discovered that they can catalytically destroy ozone. Bromine from Halons has a very similar effect. Here is what happens when these man-made molecules are released into the atmosphere: # They mix in the troposphere # They mix into the stratosphere # When exposed to UV light, the C-Cl bond is broken and the free radical Cl. is formed # Cl. reacts with ozone (O3) to form O2 and ClO, another radical. # ClO reacts with O to form O2 and Cl. # Go back to step 4. and the process repeats itself until the Cl is rained out as HCl. It could repeat ozone destruction 10,000 times plus or minus, depending only on other compounds to tie it back up, and UV not to release it again. The net chemical reaction is this: O3 + O --> 2O2 CFC's remain in the atmosphere for something like 50 years, continually destroying ozone. Since they were banned by the Montreal Protocol, they have largely been replaced by similar molecules, but these new ones are less stable. These new molecules are destroyed before they are able to reach the stratosphere, where the protective layer of ozone is found, and do not destroy ozone. Many developing nations continue to use the old dangerous CFC's however. The R12 Freon (for one example of hundreds) refrigerant was phased out due to being a Ozone (O3) destroying / interactive chemical. It was replaced with R134. Since the phasing out of R12, measurements of the Antarctic Ozone layer show that the Ozone is recovering and is therefore cited as a positive change resulting from environmental policy

Read more: http://wiki.answers.com/Q/How_does_Freo ... z1ykFQgXWQ" onclick="window.open(this.href);return false;

[WildBill]

Here ya go wild bill... I'm no chemist but .... I can google foo with the best of them

My post about sea salt was "tongue and cheek".

[sjfcontrol]

So, is it actually the consensus here that freon is the causative factor in the ozone layer hole? And how's that hole doing, anyway? I always figured it was like man-made global warming, eating bran, Cellphones causing gas stations explosions, and lead bullets causing health issues for animals (animals not shot by them). Just pseudo-science.

Seems to me the ozone hole is over the Antarctic. The Antarctic is dark 6 months or so a year. So there is no exposure to UV light, which is what generates O3 from O2.

Back in the 70s, we used a big tub of freon (don't remember number) to clean printed-circuit boards after they had been thru wave soldering. worked well.

(didn't see 03s post on the new page before posting, but am still interested in the general question of science v pseudo-sci)

[WildBill]

So, is it actually the consensus here that freon is the causative factor in the ozone layer hole? And how's that hole doing, anyway? I always figured it was like man-made global warming, eating bran, Cellphones causing gas stations explosions, and lead bullets causing health issues for animals (animals not shot by them). Just pseudo-science.

Seems to me the ozone hole is over the Antarctic. The Antarctic is dark 6 months or so a year. So there is no exposure to UV light, which is what generates O3 from O2.

Back in the 70s, we used a big tub of freon (don't remember number) to clean printed-circuit boards after they had been thru wave soldering. worked well.

Freon works very well. It is one of the best degreasers ever developed. I haven't investigated all of the science about the depletion of the ozone layer, but with the pseudo-scientific reports about global warming it causes me to be skeptical.

A question I have wondered about. Freon is many time more dense than air. How does it get all the way up to the ozone layer?

[sjfcontrol]

WB- we were cleaning flux, and other contaminants that were in the molten solder. Not what I'd consider to be grease-based, but I could be wrong.

[WildBill]

WB- we were cleaning flux, and other contaminants that were in the molten solder. Not what I'd consider to be grease-based, but I could be wrong.

Freon is an excellent solvent for flux as well as many other organic compounds. In addition to removing flux from circuit boards, I have used it to remove grease and oil from machined parts and mechanical assemblies.

[Jumping Frog]

WB- we were cleaning flux, and other contaminants that were in the molten solder. Not what I'd consider to be grease-based, but I could be wrong.

Freon is an excellent solvent for flux as well as many other organic compounds. In addition to removing flux from circuit boards, I have used it to remove grease and oil from machined parts and mechanical assemblies.

I used to wash my hands in it.

[sjfcontrol]

WB- we were cleaning flux, and other contaminants that were in the molten solder. Not what I'd consider to be grease-based, but I could be wrong.

Freon is an excellent solvent for flux as well as many other organic compounds. In addition to removing flux from circuit boards, I have used it to remove grease and oil from machined parts and mechanical assemblies.

I used to wash my hands in it.

We're you trying to avoid leaving fingerprints?

[03Lightningrocks]

Here ya go wild bill... I'm no chemist but .... I can google foo with the best of them

My post about sea salt was "tongue and cheek".

Mine about George Bush was not. Everything is George Bush jr.'s fault. Just ask Obama.

[03Lightningrocks]

I, for one, don't believe in man made global warming. I believe the earth has been warming and cooling in cycles since before man walked the surface. But, to be honest, my feelings about it are similar to a kid hoping there is a santa clause. I do everything I can, including a sun dance, to get the temperatures to rise as high as possible, just short of bursting into flames.

[sjfcontrol]

I, for one, don't believe in man made global warming. I believe the earth has been warming and cooling in cycles since before man walked the surface. But, to be honest, my feelings about it are similar to a kid hoping there is a santa clause. I do everything I can, including a sun dance, to get the temperatures to rise as high as possible, just short of bursting into flames.

Musta had a good year last summer -- almost got your wish.

[03Lightningrocks]

[flb_78]

We could go back to using propane and butane as a refrigerant.

I recharged the A/C in my old Buick with propane and it worked GREAT!!

[RPBrown]

Back in the mid-70's, I was a lab technician for Copeland Corp, an air-conditioning compressor manufacturer. I remember we had these big sinks filled with F11 that we routinely used to clean and degrease parts. Boy, times have changed . . .

Yep, we used to wash the grease off of our hands with R11.

[WildBill]

Back in the mid-70's, I was a lab technician for Copeland Corp, an air-conditioning compressor manufacturer. I remember we had these big sinks filled with F11 that we routinely used to clean and degrease parts. Boy, times have changed . . .

Yep, we used to wash the grease off of our hands with R11.

Perchloroethylene [Perc] is a great "hand cleaner" too.