So what is the difference between Co2 and Air? 

This is probably one of our most frequently asked questions and one of the most important things to consider when buying a paintball marker/paintball gun. All paintball guns run off either Co2 or Air (compressed air) and some markers will work just fine on either whilst others will only work on air.

Co2 and Air are both compressed gases and are held in paintball “tanks” which screw onto the back of the paintball marker. When the tank is screwed into the marker a small pin on the top of the tank is pushed in and this allows the gas (co2 or air) to escape from the tank and into the gun. The gas (co2 or air) in the tank is held at high pressure (from 3000psi to 4500psi) and this is released into the gun which allows the bolt mechanism to fire and paintballs to be shot!

There are a few differences between co2 and air and the most important is that air should never be put in a co2 tank and co2 should never be put in an air tank. The gases operate at different pressures and require different storage “tanks” in order to be used safely.

Choosing between compressed air and Co2

Co2 - the details

Co2 is a compressed gas and is available in either liquid or vapour form. For use in paintball it is always the liquid form that is required. The liquid is stored in the paintball tank and the gas from this liquid is released into the marker to fire the balls. The gas that is released is freezing cold and ‘not dry’ so co2 isn’t recommended for use in any markers which have electronic components. The co2 can also be damaging to internal o-rings as it is so cold it can freeze the o-rings and cause them to perish faster. Co2 is normally used on more beginner markers because they aren’t generally electronic and the o-rings are more hard wearing against the freezing cold Co2. Co2 bottles come in a variety of sizes and normally have a “pin valve” fitted to top of the bottle. The pin on the top of the valve pushes in as the tank is screwed onto the marker and every time you pull the trigger on your marker a burst of gas is released which allows the bolt to move. Each burst of gas is random and that is why sometimes Co2 is thought of as being less consistent as a power source as you cannot regulate how much pressure is put into each shot.

Air - the details

Air on the other hand is held in a tank which always has a regulator on the top instead of just a pin valve. The regulator allows the same amount of air to be released into the paintball marker every time you fire a shot. The air is generally regulated to a lower pressure than that at which it is stored in the tank and this is essential as you don’t want 4500psi of air going into your paintball marker - this would burst all the seals. The pressure coming out of a regulator is generally around 800psi although this can be changed on some regulators so it is lower or higher. Some markers like the air coming through them to be a higher pressure whereas others like it to be a lower pressure.

Compressed air is considered more consistent as a result of being regulated and also because it is not frozen down like Co2. When the air bottle is filled, as per the general laws of physics, the air rushing into the bottle is actually warm and your bottle can feel warm to the touch. It’s really careful to fill an air bottle very slowly and it should only ever be filled by someone who has been trained to fill it. Air is a dry gas and as such it is the preference for people with electronic paintball markers as it doesn’t get any hint of liquid near the marker’s solenoid/electronics and it isn’t so harmful on the internal seals.

Other things to consider...

There are other things to consider when looking at air and Co2, including where you get your tank filled, how to look after the o-rings, why you should never put oil on your air system (as it can cause a fire inside the tank) and what it means when a “burst disk” goes pop. If you’re unsure at all about anything to do with air or Co2 or still don’t know which gas you should be buying then please contact the store directly.