OB Approved CO2 vs. Air Compressors

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HeliSniper

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There is also the factor the CO2 will introduce moisture in to the tires which can cause rotting(from the condensate, you have seen the frosting right?). In Aviation & now some tire shops use Nitrogen. If I remember right it is less expensive then CO2, it is dry & the molecules are larger, thus taking longer to seep out then compressed air.
Air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases.
Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere.

So if regular old Air is 78.09% nitrogen and 20.95% oxygen, the balance being trace gases, we are only talking about roughly 21% of your tire fill for something that cost what?? and not everyone has compressed nitrogen. So you would have to carry a bottle of compressed gas (high pressure) unlike the 850psi constant of CO2.

In regards to the moisture, CO2 being a harvested gas does not inherently have moisture in it. Even though CO2 is water soluble, in the form we would get it, welding supply or Fire Extinguisher refill location, the liquid has been processed and is dry. That being said, the temperature of the gas as it vaporizes and the moisture in the air can and will cause condensation (more the closer you are to sea level and relative humidity in the air). Also, I have had air in my tires my whole life with about 1% water vapor in it and I tend to ware the tires out before any rust or other oxidation can form on the inside to cause any damage.

Bottom line, with Consumer Reports saying that the tire filled with Nitrogen and the tire filled with Air lost 2.2psi and 3.2psi respectively over the course of a year, I will opt to stay with CO2 and/or Air.
 

Nickzero

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I am no friggen scientist however I can tell you that a Co2 tank is going to suite you better than a battery driven air compressor. For 1. The tank will hold more than enough Co2 for you and your friends out on your multi day excursion. 2. It's cheap as hell to refill + many places to refill out there in society. 3. Its friggen portable (which means you can drag it 20 rigs back to supply aid to another rig). You are not limited by just your hose length from a compressor. 4. A Co2 tank really cant ever break or let you down compared to a battery driven compressor with little moving parts and seals. 5. The tank wont put a draw on your trucks battery the compressor will. 6. Depending on the type of tank / reg you have you can even quickly power pneumatic air tools. 7. Tanks look cooler and is much quieter compared to a compressor especially when camping around 50 sleeping over landers.

So thats 7 reasons to get a Co2 tanker!
Yes, I love my Power Tank!
12727 Out!
 

titicaca

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What are the downsides of CO2 with respect to moisture/corrosion:
- Tires - Will they wear out before rot happens? What if you have a summer and winter sets, would that extended lifespan expose any issues?
- Rims - This is more of a long term concern.
- TPMS sensors - how long will they last?

What are the downsides of CO2 with respect temperature affecting pressure fluctuations? One scenario being when winter brings cold temps, you will see a much bigger pressure drop on CO2 filled tires. Second scenario might be if you air up in cold mountains and drive down to a warm valley and end up overinflated. I guess you just have keep an eye on it to manage it.
 
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9Mike2

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What are the downsides of CO2 with respect to moisture/corrosion:
- Tires - Will they wear out before rot happens? What if you have a summer and winter sets, would that extended lifespan expose any issues?
- Rims - This is more of a long term concern.
- TPMS sensors - how long will they last?

What are the downsides of CO2 with respect temperature affecting pressure fluctuations? One scenario being when winter brings cold temps, you will see a much bigger pressure drop on CO2 filled tires. Second scenario might be if you air up in cold mountains and drive down to a warm valley and end up overinflated. I guess you just have keep an eye on it to manage it.
Most of what you wrote is not true with CO2, The gas is dried during the liquid faze of making it, the regular air can have most moisture in it because it is just compressed, that's why most good Garages have water traps on their air compressors, and with the use of Co2 now for five years We have had no problems with any of our TPM senors ,And as far as the inflation goes that can happen to any gas at different alt's.....
 
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titicaca

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Most of what you wrote is not true with CO2, The gas is dried during the liquid faze of making it, the regular air can have most moisture in it because it is just compressed, that's why most good Garages have water traps on their air compressors, and with the use of Co2 now for five years We have had no problems with any of our TPM senors ,And as far as the inflation goes that can happen to any gas at different alt's.....
Fair enough. I was just reading Power Tank's Q&A to dispel the myths I mentioned. Power Tank has a vested interest in this matter but the explanation is credible.

https://powertank.com/apps/help-center#!how-can-there-be-no-moisture-in-the-co2-in-my-tires-if-co2-is-a-liquid-gas-1
How can there be no moisture in the CO2 in my tires if CO2 is a liquid gas?
CO2 has the unique characteristic of being able to be stored in a dense, amorphous, liquid state under pressure (~800 psi). When CO2 is at atmospheric pressure it goes from a solid (dry ice, -100F) straight to a gas (smoke on top of the Halloween punch bowl) and skips the liquid state. Don't get CO2 confused with a more familiar chemical called H2O which goes from a solid (-32F) to a liquid and then to a gas. Does H2O condense into moisture with temperature changes? Yes. Does CO2? No. Does CO2 cause H2O to condense more with temperature changes and cause equal clump? No and no.


https://powertank.com/pages/nitrogen-truths-and-myths
THE IDEAL GAS LAW FORMULA might help explain why different gases expand at virtually the same rate as their temperature increases.

A gas may be completely described by its makeup, pressure, temperature, and volume. Where P is the pressure, V is the volume, n is the number of mols of gas, T is the absolute temperature, and R is the Universal Gas Constant,

Ideal Gas Law: PV = nRT

This formula is the "Ideal Gas Law Formula." Although there is no such thing as an ideal gas the formula is pretty accurate for N2, CO2, and oxygen as we assume that the gas molecules are point masses and the collisions of the molecules are totally elastic. (A completely elastic collision means that the energy of the molecules before a collision equals the energy of the molecules after a collision, or, to put it another way, there is no attraction among the molecules.) The formula becomes less accurate as the gas becomes very compressed and as the temperature decreases but here "very compressed" pressures are well above even the highest tire pressures and "decreased temperatures" are extremely cold, too cold for tires. There are some correction factors for both of these factors for each gas to convert it to a Real Gas Law Formula, but the Ideal Gas Law is a good estimation of the way N2, CO2 and "air" should react through temperature changes. What does all this mean? It simply means that "air", nitrogen vapor, and CO2 vapor should all react pretty much the same within normal tire pressures (0-120 PSI) and temperatures.
 

HeliSniper

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Fair enough. I was just reading Power Tank's Q&A to dispel the myths I mentioned. Power Tank has a vested interest in this matter but the explanation is credible.

https://powertank.com/apps/help-center#!how-can-there-be-no-moisture-in-the-co2-in-my-tires-if-co2-is-a-liquid-gas-1
How can there be no moisture in the CO2 in my tires if CO2 is a liquid gas?
CO2 has the unique characteristic of being able to be stored in a dense, amorphous, liquid state under pressure (~800 psi). When CO2 is at atmospheric pressure it goes from a solid (dry ice, -100F) straight to a gas (smoke on top of the Halloween punch bowl) and skips the liquid state. Don't get CO2 confused with a more familiar chemical called H2O which goes from a solid (-32F) to a liquid and then to a gas. Does H2O condense into moisture with temperature changes? Yes. Does CO2? No. Does CO2 cause H2O to condense more with temperature changes and cause equal clump? No and no.


https://powertank.com/pages/nitrogen-truths-and-myths
THE IDEAL GAS LAW FORMULA might help explain why different gases expand at virtually the same rate as their temperature increases.

A gas may be completely described by its makeup, pressure, temperature, and volume. Where P is the pressure, V is the volume, n is the number of mols of gas, T is the absolute temperature, and R is the Universal Gas Constant,

Ideal Gas Law: PV = nRT

This formula is the "Ideal Gas Law Formula." Although there is no such thing as an ideal gas the formula is pretty accurate for N2, CO2, and oxygen as we assume that the gas molecules are point masses and the collisions of the molecules are totally elastic. (A completely elastic collision means that the energy of the molecules before a collision equals the energy of the molecules after a collision, or, to put it another way, there is no attraction among the molecules.) The formula becomes less accurate as the gas becomes very compressed and as the temperature decreases but here "very compressed" pressures are well above even the highest tire pressures and "decreased temperatures" are extremely cold, too cold for tires. There are some correction factors for both of these factors for each gas to convert it to a Real Gas Law Formula, but the Ideal Gas Law is a good estimation of the way N2, CO2 and "air" should react through temperature changes. What does all this mean? It simply means that "air", nitrogen vapor, and CO2 vapor should all react pretty much the same within normal tire pressures (0-120 PSI) and temperatures.
As a SCUBA diver that likes to push boundaries while diving deep I can assure you that there are some pretty accurate GAS formulas, else I would be fish food many times over.
But it is like you say in your summation, all act close to the same at the pressures we are talking about in the realm of automotive tires.

CO2 as a liquid and referring to Nitrogen as a "Dry Gas" are totally different concepts. CO2 is stored as a liquid at around 850psi, whereas it is still a water soluble gas that can mix with H2O vapor if not but through a drying process during harvesting. Nitrogen is a "Dry Gas" that will not accumulate not transfer H2O vapor.

But here's the thing, and it is a very big thing; people take truths from one situation and apply them to all situations, or at least other situations. Like someone trying to compare the physics and physiology of pressurized gas at 530 feet while diving on the Edmund Fitzgerald as compared to airing up your tires on the side of the trail from 15psi to 35psi and wondering if it will cause condensation in their tire, thereby stating that CO2 is a water soluble gas. Yes what their saying is technically correct but so many amplitudes away that it would not matter in the least.

Wow, I need to shut-up, bottom line for me is the same as yours, ....all react pretty much the same within normal tire pressures. I would also add that CO2 is a perfectly acceptable gas for airing up your tires.
 
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