CO2, COMPRESSED AIR, N2, HPA, HPS
If you are new to paintball, these words may seem confusing. In reality, the differences are fairly simple. For paintball purposes, CO2 (carbon dioxide) is the most common type of paintball propellant. The other terms: nitrogen, N2, HPA, HPS and compressed air are all the same thing and are used as paintball propellant also. The terms can be confusing but once you learn the difference, you may find an answer to a problem you've been having.
CARBON DIOXIDE
The Carbon Dioxide inside your tank, is a liquid at the bottom and a gas at the top. You know that when your CO2 tank is filled, they weigh it, right? Well, at room temperature, CO2 in the tank is naturally stored at 800 PSI and what they weigh is the LIQUID. The CO2 GAS has no negligible weight. So you've got liquid and gas in the tank and the gas is what you need to work the marker. NOTE: some markers operate fine on liquid CO2 but they are set up to do so. Under most applications, liquid is NOT good. CO2 at room temperature always wants to get to about 800psi. If there is enough liquid to convert to gas, CO2 will maintain a fairly constant pressure.
Here is the problem. To convert liquid CO2 to gas, the CO2 needs HEAT.... Like water changes to steam when you boil a pot on the stove. The heat makes it evaporate. Well, you pull the trigger, the gas in the tank cruises through the marker and makes the paintball launch out of the barrel. As soon as some gas leaves the tank, the CO2 uses some heat to exchange the liquid to more gas at 800psi. Now one shot is no big deal. But when you rapid fire, it takes a lot of heat to keep enough gas at 800psi and, if you run out of gas or pressure, your marker will act stupid. If you rapid fire 20 or so paintballs out of your marker, you will probably see and feel frost on your marker and tank. This is the result of the conversion (use of heat) of the liquid CO2 to gas.
OK, you get into a good gunfight. You have good cover, plenty of paint, and the other guy is in the open. Suddenly your marker looses velocity and after you wipe the paint off your goggles, you see LIQUID dripping out of your barrel... AAAAAARRRRRRGGGGGGHHHHHHHHH ! ! ! ! ! ! ! ! ! ! NOW WHAT!? Well, if it is available, running WARM water over the TANK just before the game may help. **NO: HOT WATER, OPEN FLAME, OR BLOW DRYER. EXTREME HEAT MAY DAMAGE YOUR TANK AND IT COULD EXPLODE WITHOUT WARNING. THIS INCLUDES STORING YOUR TANK IN A VEHICLE.
Another possible solution is to add an EXPANSION CHAMBER to your marker. This is probably the best solution and it doubles as a foregrip. An expansion chamber is as its name implies, it is room for the liquid CO2 to get heat and expand to a gas. An expansion chamber and new lines are easy enough to install, but most pro shops will install one for free if you buy from them. Expansion chambers come in a huge variety of styles and methods of converting liquid CO2 to gas. Do the research.
Adding an ANTI-SIPHON tube to your tank may also help, but a qualified airsmith needs to install it and then the tank will only work on your gun. An anti-siphon tube is a bent tube installed inside your tank. When you are lying down on the field with a back bottle configuration, liquid CO2 is at the tank valve. You can see it is easy to get liquid CO2 into your marker that way so, the anti-siphon tube is bent up to keep the inlet out of the liquid and into the gas.
The last method may be the least expensive (other that warm water). Adding a REMOTE LINE is a simple operation. One end of the line screws into the marker where the bottle used to. The other end of the line is where you connect your bottle. Now if liquid gets into the line, it has lots of space to expand before it gets to the marker. The remote line also gets the tank off the marker and somewhere less conspicuous...like in a harness or backpack.
If you experience problems with CO2, these ideas may help, and people are always coming up with new ways to resolve the problems inherent with CO2 like using a high-pressure system. Keep in mind: CO2 is easy to find and relatively cheap. CO2 systems are dependable, and the tanks and accessories are inexpensive.
COMPRESSED AIR
You've read this far?might as well finish. Nitrogen, HPA, and Compressed Air are all basically the same thing. Nitrogen accounts for 80% of the air we breathe. Compressed Air (what divers fill their scuba tanks with) and N2 are both very stable and remain in a gaseous state under pressure. With CO2, the pressure does not fluctuate much until you rapid fire or run low on liquid CO2. The liquid CO2 controls the pressure. With a High Pressure System you must have a REGULATOR to control the pressure. As you use the marker over time the pressure drops until there is not enough pressure to operate the marker.
High-pressure systems are sometimes tricky because of the regulator. Once you have the regulator set properly, the system will be very dependable. Fluctuations in velocity and freeze up during rapid fire will not happen. Also the life of internal seals and components will be longer because Compressed Air is cleaner.
High Pressure Systems can be expensive. Tanks come in all sorts of capacities and two pressures: 3000 and 4500 psi. You also need a good regulator to control the pressure going to the marker. Beyond the parts for the marker, you will need a scuba tank and a fill station to refill the tank on your marker. You don't need remotes or expansion chambers because there is no conversion from liquid to gas. If you have a dive shop near you, and you buy a large 4500psi tank for your marker, HPA may be the answer.