I would guess the most often asked question with new players is what is the difference between using Compressed Air and CO2 (Carbon Dioxide). Both propellant systems will shoot a paintball out of your marker, but CO2 is not compatible with all markers.
CO2 (Carbon Dioxide) was the first gas used in paintball and set the standard many years ago. For paintball we have two options when using CO2. First is the 12 Gram Cartridges (commonly used in paintball pistols and pump markers like the Phantom) and second are refillable CO2 tanks that screw into an Air Source Adapter on your marker. Both are filled with liquid CO2 which will expand to create pressure used for the marker to shoot paintballs. The pressure can fluctuate due to elevation, temperature and other outside variables.
Using CO2 can have advantages in that you can get more shots per tank and there are usually more places local to the user to fill them up. You can find many gas and welding supply companies as well as fire extinguisher shops that will have the means to fill the tanks. The number one reason for the prevalent use of CO2 is the low cost associated with the tanks.
There are drawbacks to using CO2 also. Because CO2 is in a liquid form it cools as it expands. Not a big deal if you do not shoot much but it is very noticeable if you shoot a lot of paint. The pressure can and will fluctuate high and low with the result of your markers performance and accuracy will suffer. As the tank chills it begins to draw liquid CO2 into the marker resulting in pressure spikes that can boost velocities to an unsafe level. If you see snow or ice coming out of your barrel when shooting you can bet that liquid CO2 has made its way into your marker. In cold weather the pressure can get too low to cycle your paintball marker or make it not cycle properly. CO2 can be hard on the seals in your marker and damage solenoids of many electro pneumatic markers on the market today.
Compressed Air (Also know as HPA, Nitro or Nitrogen) is simply put, air compressed as it enters your tank. Rather than filling the tank with liquid Carbon Dioxide they are instead pressurized up to the tanks rating of 3000psi or 4500psi. The pressure is then regulated through the tanks output regulator down to 850psi (High Output) or 450psi (Low Output). The best thing about Compressed Air is that it is much more stable than CO2 is. You do not get changes in pressure due to shooting fast or playing in cold weather. No thick clouds of “smoke†exiting your barrel when you fire. All in all it is just a cleaner propellant to use with today’s electro pneumatic markers.
Compressed Air does have some drawbacks. In some areas getting the tanks refilled can be a problem as regular shop compressors do not have the output pressure to refill them. The tanks are a bit larger than than a standard CO2 tank. The cost of a Compressed Air tank is much higher than CO2 tanks by far.
Compressed Air tanks are the better investment in the long run. They have better all weather performance than CO2 and you can transfer it from one marker to another without the fear of damaging the internals of your markers. I personally prefer Compressed Air over CO2 but you will have to weigh the good vs. bad options for your budget.
As always, buy the best you can afford and get out there and play.
By Paul Forcier
Just a small thing to add, HPA tanks can also be had with adjustible regulators (although not so common these days) this will let you pick the opperating pressure your marker needs between 100 and 1500psi depending on the reg. Usualy adjustible regulators will provide better consistancy as well. HPA is not compatible with all markers (although just about any newer one will be fine) some low end blowback markers will not cycle properly with it the Tippmann RT system also SOMETIMES doesn’t like it, I’ve had to do extensive work on some A5 and X7 markers to get them to play nice with HPA and my 98 just won’t work no matter what I try. That said if you do decide to use CO2 an anti-syphen tube is an excelent preformance and safty upgrade provided you don’t use a remote (it will however make the tank only usuable with one ASA without haveing to be resetup) This small and usualy cheep item will keep liquid CO2 out of your marker in all but the worst situations. If you don’t put in an anti-syphen please for the love of god don’t walk around with your CO2 tank on the marker and the barrel pointed down, this poors liquid into the marker and as a ref I have taken a shot in the neck that took several minuts to stop bleeding from a gun that shot 460fps when it had been pointed down for a while and 260fps after the first shot had cleared all the liquid from the valve… not cool… please, please, please keep this in mind it’s somthing that no one tells new players any more.