Compressed Air VS. CO2

A technical Blog By Brian

We have decided to create a blog for all of us here at the store to contribute to. The general idea is that we’ve all been around the industry for a while, and we have a lot of knowledge. Knowledge about product, playing tips, teamwork, technical issues, new products, upgrading your marker, and just about everything else relating to paintball as a sport and as an industry. We’ve also collected a large amount of stories, some comical, some ironic, some just plain weird. So we’re all going to be writing entries to this blog, to help you get a better understanding of the sport of paintball. As well as a bit of an inside look at the inner workings of a busy paintball store.
As I was thinking about what to write my first Blog entry on, I just thought about what questions are asked of me most often. By far the most common question people ask me is about CO2, verses Compressed air, Verses Nitro or Nitrogen. Well here we go.
The first misconception about compressed air and Nitrogen, is that they are two different things. We see those two names as well as N2, Nitro, HPA, High Pressure Air, and others I’m sure I’m leaving out. In the world of science, they are two different things, but in paintball they are all names for the same air source. Regular compressed breathing air (which is what we actually use in paintball) is about 80% nitrogen by nature, and some people think the “nitro” name sounds cooler, so that is the only reason that those names are used.
With that out of the way we can now compare the only two air sources in paintball. CO2 and Compressed air.
CO2 is a liquid. When you pull the trigger, a small amount of the liquid is released into the gun. This liquid then quickly expands to a Gas. This rapid expansion creates pressure, the pressure to fire the ball. This expansion is unregulated, and can be affected by many factors. Such as the temperature outside, the rate at which you fire your gun, and the time between your bursts of fire. Take for instance, you go out and Chronograph your gun (test the speed that the balls are leaving the barrel) You set your gun up in the morning when it is cool and your gun is shooting 280 FPS (Feet per Second). You go out and play for a few hours, the temperature rises, and the tank is up against your body as you march your way through the woods. Now the CO2 is coming out and expanding much faster. So you chronograph again. This time instead of 280 FPS, you’re shooting 320FPS. Well above safe limits. So you dial your gun back down to 280. You decide to break for lunch, and set your gun in the shade. As you eat, the temperature of the tank falls back down, when you chronograph after lunch your gun is now shooting only 260FPS.
Now, there is another factor that also changes the temperature of the tank...You shooting.
With CO2, the faster you shoot, the colder it gets. The colder it gets the slower it expands, the slower it expands, the slower your shots. So as you can see, there are a lot of factors that will affect the amount of air behind your ball when you fire your Marker.
Compressed air, on the other hand, is very different. Instead of a liquid expanding to a gas, this air is already in the gas form. Highly compressed, to 3000 or 4500 PSI (pounds per square inch!), then REGULATED to 800Psi output. It is important to note here that it is only high pressure in the tank itself. It is not pushing through 3000 PSI to your gun. (That would blow something up, I’ve seen it) there is a regulator built on to every compressed air tank out there, so that it outputs to your gun only 800PSI, or less with some tanks.
With a compressed air tank, every time you pull the trigger, you get exactly the same amount of air. No more variance.
If you want an accurate paintball marker, step one should always be a compressed air tank. I often use the analogy of shooting an actual rifle. If there was a different amount of powder behind every bullet, you would never know where that bullet was going to go, it would be totally random. This is like Co2. But it’s not like that. There is a precise amount of powder behind every bullet so that you can count on that shot going right to it’s target. This is like compressed air. Instead of gun powder, we have a compressed gas, and depending on which gas you choose will determine how consistent your shot is going to be.
I read an article a couple years ago, I can’t find it any more, although if I do I will post it or link to it so you can read it yourself. But essentially it was written by a barrel company who accidentally did a great study of co2 vs. Compressed air out in the field. They were testing this new barrel they developed with a very accurate gun, high quality paint and a Co2 tank. The target was 100 feet away. They sighted in the gun then fired ten shots in a row. The first shot was right on target, but the tenth shot was over 4 feet away. This was caused by the sudden pressure drop as well as the condensation caused by the liquid Co2. They did the same test with the same barrel, paint, gun, and target. This time they used Compressed air. The results?... After 10 shots they were all within 10 inches of each other. That’s over 3 feet of difference at just 100 feet of range!
The difference is huge between Co2 and compressed air. But there is a cost difference as well. Co2 tanks start at about $10 at EVpaintball.com, Where as compressed air tanks start as $59.95. The cost of filling the tanks is about the same, although compressed air is just a little cheaper per shot.
I know I’ve been long winded is describing the differences, but there is one more myth I have to clear up. That myth is that only certain guns will take compressed air. This is quite the opposite. Any paintball gun, even the $40 Wal-Mart variety will take compressed air. You don’t need any adaptors, regulators, or special abilities. Just buy the tank, then screw it on, BAM instant upgrade.
So, to conclude my first and very long Blog entry, compressed air is a huge upgrade that I recommend to everybody. I do realize the cost is higher, so not everybody can afford to get one right away. But as soon as you can put $59 towards a tank, I would do it because it will make your gun shoot like a whole new beast.
Thanks for reading, stay tuned for more helpful hints, and useless tidbits.
-Brian
EVpaintball.com