HPA vs CO2 – Real Differences and Usage 2022

Last Updated on May 5, 2022 by Jezus Fischer

Majority of the paintball guns are compatible with both HPA and CO2 which becomes tricky for an absolute beginner to decide which propellant to choose. Well, both serve the same purpose of launching the paintball. However, there are few differences between CO2 and compressed air and that’s the reason they are the players’ choices for propellant.

Veteran players prefer playing using HPA tank as they fire with better accuracy and consistency. Whereas, CO2 is used by beginners players because it is cheap and easy to fill.

hpa vs co2

To learn more about the HPA vs. CO2 difference, stick till the end. I will help you to decide which propellant to use in your next game.

Difference Between CO2 and HPA

FactorsCompressed AirCO2
ConstituentsOxygen, nitrogen, and carbon dioxideOnly carbon dioxide
State in tankGasLiquid
SizeBulky in sizeSmall & Compact
PerformanceConsistent and accurateBecomes inconsistent in cold weather
Durability of MarkerSmooth on markersDamages the internal parts of electro pneumatic marker
RefillCan be refilled at the pro shop only and on the paintball fieldCan be refilled at the pro shop, welding shop, or fire brigade station
IssuesNo issue of white cloudsProduces dry ice
Regulator GuagesThey do have to regulate the pressure of HPA according to the marker’s working pressureNo. they don’t have it.
Best for Electro pneumatic markersPump style and lower-end mechanical markers

CO2 Carbon Dioxide

Let’s recall the lower grade Chemistry lecture, carbon dioxide is the scientific name of CO2. It is a gas that is available in our atmosphere in a gaseous state. But it changes its state to liquid when it is compressed to store in a tank. So the CO2 in the tank is in the liquid state. When liquid CO2 converts into gas it expands, which creates some pressure and it’s because of this pressure that the gun fires. The pressure that it generates is 850 psi, but due to certain factors, this pressure may fluctuate which affects the performance of your marker.

The first paintball gun that is Nelspot 007 was operated using a CO2 tank. In the initial days of paintball, people prefer to use CO2 because it is denser than other air. That’s why it uses 850psi rated tank.

Working of CO2:

The co2 tank that you have inserted in your gun has liquid co2 which is compressed by exerting the pressure of 850psi that converts it into gas, as the co2 expands, and it escapes out of the chamber. So when the player pulls the trigger of the marker, he actually activates the valve which in turn activates the CO2 tank. This will expel the gas to shot the paintball from the gun. In short, every time you pull the trigger you are changing CO2 from liquid to gas.

CO2 needs certain conditions in order to convert from a liquid state into gas. The first and the foremost thing is the temperature of CO2 in the tank, it should be 75F. Lower than this will result in a decrease in pressure. But let me share with you an interesting fact about CO2 when it expands it cools down. So for every 1F drop in pressure, the temperature of the tank decreased by 11PSI. 

Types of CO2 Tanks:

CO2 is available in two types of tanks for paintballers, which are:

  • Non-refillable: also known as disposable cartridges that are available in 12-gram cartridges. Usually, disposable cartridges are used in paintball pistols and pump markers.
  • Refillable: These CO2 tanks are made up of aluminum. They are available in various sizes ranging from 9 oz to 24 oz. But the 20-ounce size is the most common size of CO2 tanks. These tanks can be easily refilled as per their weight.

CO2 is Best for:

CO2 is compatible with many paintball markers, but it is preferable to use with mechanical markers which do not have a complicated internal mechanism. CO2 is not preferable to use with an electro-pneumatic marker as it destroys the solenoid. Actually, the rapid expansion and frequent increase or decrease in PSI simply destroy your electro-pneumatic marker. CO2 is best for beginner players who use lower-end markers.

Advantages of CO2:

Here are the few pros of CO2 that you won’t find in HPA:

  • CO2 tanks are affordable and easily available at low prices. You can have a full day supply of CO2 while remaining on your budget.
  • CO2 tanks are easy to refill and amazingly it is relatively inexpensive to fill.
  • It can be refilled from the pro shop if not available then welding shops could be the next option.
  • CO2 tanks are compact and light in weight.

Drawbacks of CO2:

With some benefits, few drawbacks make people to use HPA over CO2. Here they are;

  • CO2 when expands causes chilling of the gun and tank. The more it expands the colder the tank would be.
  • When it gets chill it results in a drop in pressure that affects the overall performance of guns like range and accuracy.
  • Liquid CO2 may leak in the gun that produces dry ice in form of white clouds from the barrel while shooting.
  • Leaked liquid co2 damages the o-rings of the marker.
  • It damages the electronic parts of an electro-pneumatic gun.
  • You can’t determine the amount of CO2 in the tank that is left during the game.

HPA (High Pressure Air)

Due to the limitations of Cos cartridges, players started looking for other options for propellant. Then somewhere in 1990 HPA was introduced as gas for propelling paintball into the barrel.

High-pressure air or HPA is the compressed air that is around us. Initially, nitrogen was compressed and force inside the container to be used as a propellant but now it is comprised of all the gases that are there in our atmospheres like nitrogen, oxygen, and carbon dioxide. The gases are compressed to force into the container by applying high pressure. That’s whys it is termed high pressure.

HPA is pressurized into the tank with a pressure rating of 4000-4500psi. Usually, with the help of the tank’s regulator, this pressure is regulated to the marker’s working pressure that would be 850psi or less than that.

The best thing about HPA is, no matter how much you compressed or apply pressure on it, it remains in a gaseous state. Therefore it ultimately resolves all drawbacks related to the liquid state of CO2 or phase change.

Working of HPA:

The working of HPA is pretty similar to CO2; just skip the step of phase conversion. The rest is same as CO2. When you pull the trigger, gas releases with the marker’s specific pressure and expels the paintball out of the barrel.

Types of HPA Tanks:

You will find two types of HPA tanks;

  • Aluminum Tank: They are small in size as they are made up of aluminum. But mind you they are pretty heavier than fiber-wrapped tanks. Aluminum tanks are available till 3000 psi not more than that. They are affordable.
  • Fiber-wrapped Tank: These tanks are wrapped with a fiberglass coating. The pressure that the gas can withstand in fiber wrapped tank is 3000psi or 4500psi. They are pretty expensive but they are light in weight.

As far as the HPA tank sizes are concerned, Aluminum tank and fiber wrapped tanks are available in many sizes with only two pressure rating that is 3000psi and 4500psi.

HPA is Best For:

Compressed air (HPA) is not affected by temperature changes, like co2. Therefore it is an ideal choice of propellant in cold weather. Also, it is best to be used with an electro-pneumatic marker because of its fast shooting rate. It is best for speedball players who use electro-pneumatic markers.

Advantage of HPA:

Following are the advantages of compressed air that make it superior to CO2.

  • HPA tanks give consistent firings no matter you are shooting the 100th time. Neither cold weather nor rapid-firing affects the performance of the tank.
  • No fear of leaking inside the marker.
  • Doesn’t damages the seal and electronic part of the marker.
  • Using a pressure gauge, you can determine the amount of gas in the tank.
  • HPA gas can be filled during the game by the paintball field staff.

Drawbacks of Compressed Air:

With the biggest advantage of consistent firing at the same pressure, the drawbacks of compressed air become negligible. Here they are;

  • HPA tanks are pretty costly. But it’s a one-time expense.
  • They are very bulky and heavy in size.
  • If you don’t have access to a local pro shop then filling it would be the biggest hurdle.

CO2 VS. Compressed Air (Which one is BEST)

Till here, differences between co2 and compressed air are pretty much clear.

If you have just entered into the world of paintball and are unsure about your stay in paintball the using playing with CO2 is a great idea. Naïve players don’t even get the difference between CO2 and HPA. Once you get pro, you can switch to other types of propellant. But buying an expensive and long-lasting HPA tank for playing on holidays is just a foolish decision.

HPA is best. And is the best investment if you are an intense paintballer. Not only for you, but it’s good for your gun also. It is gentle on your gun and its interior. And the biggest of all is, firing rate and cold weather doesn’t impact the accuracy and consistency of the gun.


For paintball, Compressed air and CO2 are used as propellants. But nowadays people prefer to play with HPA tanks because of the accuracy it offers. That’s why CO2 has become outdated, and now the majority of the paintball fields allows only HPA gas tank. So if you are a newbie, shift yourself to HPA as soon as possible, it has lots of benefits.