Why use another gas?

[HunterT]

I don't know if this is the right fourm to ask this.

I was wondering what the idea is behind using C02 or nitogen or helium gas for air cannons? Does it giver better performance?

[MrCrowley]

People use CO2 because it is readily available, cheap and stored at a high pressure. The negative side to it is that it is heavier than air which will lower performance. Nitrogen is available at even higher pressures than CO2 and is also lighter than air, this will increase performance compared to using CO2 or just compressed air. Helium is even lighter than air, nitrogen or CO2 and can drastically increase performance compared to using just compressed air.

[MRR]

As lighter the gas, that you are using compared to the surrounding gas, as faster it expands. Therefore the projectile is accelerated to a higher velocity.

[D_Hall]

Note, however, that for 99% of the designs out there, you'll never notice the difference in performance between the various gases. Unless you're running a transonic gun, your best bet is to simply use whatever is cheapest/easiest for you to obtain.

[Technician1002]

People use CO2 because it is readily available, cheap and stored at a high pressure. The negative side to it is that it is heavier than air which will lower performance. Nitrogen is available at even higher pressures than CO2 and is also lighter than air, this will increase performance compared to using CO2 or just compressed air. Helium is even lighter than air, nitrogen or CO2 and can drastically increase performance compared to using just compressed air.

Air is almost 80% Nitrogen so using it provides almost identical performance.

When using light gases, a barrel seal is essential. Light gas has much higher blow by in the barrel when the projectile is not a 100% seal. This is why dense gas such as CO2 will outperform Nithogen or air in pellet, BB, and paintball guns.

[HunterT]

SO the lighter the gas and the better the seal, the more velocity?

[MrCrowley]

Air is almost 80% Nitrogen so using it provides almost identical performance.

Yeah I think Nitrogen is only about 3% lighter or so...guess I shouldn't have said it would increase performance, as you said, it probably wouldn't make a noticable difference.

[Technician1002]

SO the lighter the gas and the better the seal, the more velocity?

The effect is less with heavy projectiels and more with very light projectiles, providing the better seal doesn't carry a higher friction penalty.

There is an art to using light gas. Little leaks are much bigger with light gas.

[jackssmirkingrevenge]

People use CO2 because it is readily available, cheap and stored at a high pressure. The negative side to it is that it is heavier than air which will lower performance.

Not to mention that it's KILLING THE PLANET

[Insomniac]

Not to mention that it's KILLING THE PLANET

Quick, everyone stop breathing!

[jackssmirkingrevenge]

Quick, everyone stop breathing!

Even that won't work, because we'll die and give off methane while we decompose, that's another greenhouse gas

[MrCrowley]

Quick, everyone stop breathing!

Even that won't work, because we'll die and give off methane while we decompose, that's another greenhouse gas

Only one solution...

[jackssmirkingrevenge]

I drive a Landrover *ducks expecting a flurry of "don't you mean jeep" comments * so I clearly don't give a rodent's sphincter. 'night night my children's children

[Technician1002]

Not to mention that it's KILLING THE PLANET

Just because you take CO2 from the environment and put it in a bottle, and then release it back to the environment, it doesn't cause death of the planet.

Might as well ban beer, and soda pop, and burning plants. Growing plants take in CO2 and when burned, release CO2. Oh my, what a disaster.

People, we live on a sealed closed cycle planet. We have limited amounts of Carbon, Oxygen, Hydrogen, and other elements. There is a cycle of combining some of them to make compounds, and compounds are taken back apart to get the elements.

CO2 happens to be part of the Fuel and Oxygen cycle.

Burning lots of Fuel does reduce the Oxygen and Carbon while increasing the CO2. Our crime is paving our fertile valleys to build cities and reduce the plants that reverse the process. When food shortages, fuel shortages, and high temperatures take care of the overpopulation, the plant life will take over and the cycle will correct itself. It has happened before. Look to the current abundance of coal for the history record of a prior CO2 spike and rampant plant growth.

I know it's going to be difficult to live during the global famine, but that is part of the cycle.

Some greenhouses are now using added CO2 to improve the crop yeild.

A quick Google search will show this is popular with high cash value plants that might not be legal to grow in your location.

Plants love hot wet places with lots of CO2.

[jackssmirkingrevenge]

Just because you take CO2 from the environment and put it in a bottle, and then release it back to the environment, it doesn't cause death of the planet.

Tech, I was clearly being sarcastic