Paintball's Great Debate: HPA or CO2!
Gas? What Gas?
Paintball markers require gas pressure to operate. Pneumatics & such. And of these gases, there are two used in paintball:
- CO2: carbon dioxide, same stuff we exhale, same stuff trees inhale (is that accurate? i'm no botanist), same stuff dried ice is made of. CO2 tank sizes are expressed in ounces, as the way they are filled is by weighing them (co2 tank refills are mostly liquid co2).
- HPA: or compressed air, the air we breathe, just greatly compressed... considered a gas since air itself is a collection of various gases. HPA stands for high pressure air, as the air is compressed to a very high pressure. Older nickname is nitro but there's no solid evidence as to why; my guess is the name carried over from nitrous-oxide tanks used in some street racers. HPA tank sizes are a bit more complicated, as they are expressed in both physical size (volume measured in ci, or cubic inches) and pressure capacity (psi, or pounds per square inch). Higher numbers of either (or both) will wield more shots per fill, although greater volumes mean larger tanks.
Pros & Cons
Generally, people will say HPA is better than CO2. I'll go over why... and, surprisingly, why not.
- CO2: tanks are cheaper, no question. $10-20, depending on size. You'll get more shots per unit from co2 versus air, as co2 creates quite a lot of pressure as it expands. And co2 refills are available nearly everywhere since it's used for many applications outside of paintball. But co2 tanks have a darkside - co2 tank fills are mostly liquid co2 (brrrrrrr!). The liquid converts to gas, which is all well & good, but sometimes the unconverted liquid sneaks in. Being super cold, the liquid can damage o-rings (think frostbite), cause frosty shots that can spike marker velocity to unsafe levels, and in more complex paintball markers they can damage sensitive parts. In very cold environmental conditions (playing in winter, perhaps), the liquid converts slower, making co2 less efficient.
- HPA: practically any paintball marker can use hpa. It's just air, so none of the downsides associated with co2. Because hpa tanks contain such extreme pressures, which would mean they could feed extreme pressures into the marker, they have regulators installed that do exactly what the name implies - they regulate the air output, providing a more consistent & reliable gas source. Just a couple downers, though: the tanks cost more ($40-50 for the cheapest ones, $150+ for the most expensive ones). Since hpa tanks use amazingly highly pressurized air, the necessary compressors needed to fill them have to be buff, and being buff means being crazy expensive, like thousands of dollars. Because of that high cost, not every place has such a setup. So not everybody has access to hpa refills.
So Which One, Already??
This may be a face-palm moment, but hopefully you'll already know what type of gas you have access to before getting a paintball marker, for the reasons stated above. Although, chances are you've already got a marker and a co2 tank if you're reading this, and simply trying to decide whether to upgrade to hpa or not. If that's the case, then determine whether you have access to hpa refills first, either at your paintball park of choice, a paintball store, scuba shop, or wherever, keeping in mind you can't use a simple home air compressor or even a gas station air compressor (they're not strong enough). If not, stick with co2 and go play some paintball.
If you do have access to hpa refills and want to upgrade to hpa, then determine how much money you can spend on a new tank first. The cheaper hpa tanks are made of aluminum so they're a little heavier, and hold less air (less air = less shots, but hey, cheaper for a reason), while the expensive ones are made of carbon fiber, weighing less, and are available in a variety of sizes to accommodate different player preferences.
There are ways to use co2 safely in any gun, but typically the cost of doing so outweighs the advantages of simply switching to hpa. In another hub, i'll explain How to Make CO2 Work for You!