How Does an Oxygen Concentrator Work?

If your doctor has suggested that you or a loved one use an oxygen concentrator for your oxygen therapy treatments, you may be wondering, “What is an oxygen concentrator and how does an oxygen concentrator work?” The basic idea is simple: Oxygen concentrators are able to purify and concentrate the surrounding air to deliver an endless supply of concentrated oxygen to you, as long as the oxygen concentrator has power. Learn more below about the details of how oxygen concentrators pull the oxygen from the air around us, and why using this kind of oxygen generator improves oxygen therapy for you. 

What Is an Oxygen Concentrator?

An oxygen concentrator (sometimes called an O2 concentrator, oxygen machine or O2 concentrator, oxygen machine or oxygen generator) is a medical device used to deliver oxygen to those who require it. People may require an O2 concentrator if they have a condition that causes or results in low levels of oxygen in their blood. An oxygen concentrator must be obtained via prescription, and therefore cannot be purchased over the counter. If you need an oxygen machine but are unable to purchase one, an oxygen concentrator can be rented with your prescription as well. 

So how does an oxygen generator work? Oxygen concentrators are powered by plugging into an electrical outlet or by battery. If the oxygen generator is powered by an electric battery, that battery will need to be charged by plugging into an outlet. Once powered, an oxygen machine concentrates and purifies the surrounding air to provide the oxygen you need. Several parts make up an O2 concentrator, including a compressor, sieve bed filter and circuit boards.

How does an oxygen concentrator work differently from other oxygen delivery systems? An oxygen concentrator has a compressing element, but it should not be confused with compressed oxygen or an oxygen tank. The compressed oxygen inside an oxygen tank is a set amount of oxygen that is dispensed to the user, eventually requiring a refill or replacement when the oxygen inside the tank runs out. People using compressed oxygen tanks must keep several tanks on hand to ensure that they do not run out of oxygen before receiving a refill. An oxygen concentrator, on the other hand, is an oxygen machine that pulls in air from the atmosphere, purifies it, compresses it and then delivers the oxygen-rich air continuously to the user. So, though it may sometimes be called an “oxygen generator,” an oxygen concentrator does not actually generate oxygen; instead, it pulls oxygen from the air around you. 

If you are wondering, “How does an oxygen generator work without requiring refills?” no refills are needed because the oxygen concentrator simply uses the surrounding air to create oxygen-rich air, meaning the oxygen supply will never run out as long as it is powered and has access to an air supply. Instead of refilling compressed air, an oxygen concentrator just needs access to power and open air.

How Does an Oxygen Concentrator Work?

If you are still wondering, “How does an oxygen generator work?” here are some additional details. An oxygen concentrator works much like a window air conditioning unit: it takes in air, modifies it and delivers it in a new form. An oxygen concentrator is engineered to take in the surrounding air, compressing and purifying it by removing other agents that make breathing difficult for the person receiving supplemental oxygen. The O2 concentrator then produces oxygen-rich air that is immediately ready for use by people requiring medical oxygen due to breathing difficulties and low oxygen levels in their blood.

How does an oxygen generator work? 

  1. Pulls in air from its surroundings
  2. Compresses the air, while the cooling mechanism keeps the concentrator from overheating
  3. Removes nitrogen and other impurities from the air via filter and sieve beds
  4. Adjusts delivery settings with an electronic interface
  5. Delivers the purified oxygen to the user via a nasal cannula or mask

How Does a Portable Oxygen Concentrator Work?

How does a portable oxygen concentrator work differently from a stationary oxygen concentrator? Quite simply, portable oxygen concentrators are made to travel with you, so they are lighter than stationary oxygen concentrators and are able to run for a certain amount of time on battery power before requiring that you recharge your oxygen machine. In some cases, stationary oxygen generator units are made to provide continuous flow oxygen, while most portable oxygen concentrator units provide pulse dose oxygen. Otherwise, portable concentrators work the same way as a stationary system. The difference is in how you use them. 

Why Choose an Oxygen Concentrator Over an Oxygen Tank?

An oxygen concentrator offers a variety of benefits when compared with an oxygen tank. First, oxygen tanks of all kinds only contain a finite amount of oxygen, so they must be refilled or replaced regularly by an oxygen provider. This means you have to plan carefully, so you do not run out of oxygen, and so you are able to make time to get your tanks refilled or replaced on time. Oxygen concentrators, on the other hand, can provide an endless supply of oxygen as long as they have power. This means that with an oxygen concentrator, as long as you have access to a power source or a charged battery, you will never run out of oxygen.

Additionally, oxygen tanks are quite heavy and difficult to move around, even from room to room. Even smaller “portable” tanks are heavy and unwieldy. Oxygen concentrators, on the other hand, can be quite small, with many portable oxygen concentrator models weighing less than 5 pounds and some home oxygen concentrators less than 20 pounds. This not only makes going about your daily activities with an oxygen concentrator at home much easier, but it also means you can leave your home with a fully charged portable oxygen concentrator for hours at a time, without worrying about getting tired of carrying it. Simply put, oxygen concentrators make life on oxygen therapy much easier.

Moreover, since leaving the house has become more complicated with the novel coronavirus pandemic, using an oxygen concentrator simplifies the process for you. You will not have to worry about multiple points of contact when refilling or replacing oxygen tanks. With an oxygen concentrator, you can simply turn your unit on, put your cloth face covering on over your nasal cannula and go, without worrying about messing with the flow knob or lugging around a heavy tank. Additionally, cleaning and maintaining an oxygen concentrator is quite easy, which means that disinfecting after going out in public is as easy as it can be. Under normal circumstances, an oxygen concentrator makes your life easier. Under these unprecedented circumstances, using an oxygen concentrator can drastically improve your life. So how does the Inogen One make oxygen, and do you use it?

How to Use a Portable Oxygen Concentrator

So how does a portable oxygen concentrator work for you? If you are wondering how to use a portable oxygen concentrator, it is quite simple. As always, read and follow the manufacturer’s directions carefully, but in many cases, you will follow the same basic procedure. Here is how to use a portable oxygen concentrator.

  1. Make sure you have adequate power for your oxygen machine, either via a fully charged battery or an available AC or DC power source 
  2. Ensure you have a clean nasal cannula, or mask, and tubing properly attached to the nozzle fitting on your oxygen generator
  3. Ensure your particle filter is properly attached to ensure particles are not drawn into the oxygen machine as they could damage it
  4. Make sure you place the oxygen concentrator in a well-ventilated area (or that your carrying bag allows proper ventilation) as the intake and exhaust must have clear access to work properly
  5. Press the power button and allow the oxygen concentrator to warm up properly to ensure it reaches the correct oxygen concentration levels before use. Your model should indicate when the O2 concentrator is ready for use
  6. Set the portable oxygen concentrator to your prescribed flow rate setting
  7. Place the nasal cannula into your nostrils and over your ears, adjusting for proper and comfortable fit, then breathe through your nose to begin getting oxygen from your O2 concentrator.

Inogen One Oxygen Concentrators

Inogen was founded on the conviction that oxygen therapy technology needed to advance in order to help patients continue to live long, active lives. We continue to work on creating innovative oxygen delivery products because we believe oxygen therapy should help improve your life, not make it more difficult. As a result, we worked to create our compact, lightweight oxygen concentrators to help make life easier for oxygen patients. Each oxygen generator we develop helps free oxygen patients from being stuck in one spot and managing heavy, cumbersome tanks, awkward travel and refills or replacements. All of Inogen’s concentrators are  clinically validated to deliver oxygen 24 hours a day, 7 days a week. With Inogen, you can reclaim your freedom, mobility and independence, allowing you to live the way you want while getting the oxygen you need. Oxygen. Anytime. Anywhere. 

So how does the Inogen One make oxygen? If you’ve been using an oxygen tank system or a stationary oxygen concentrator and you want to learn more about how to use a portable oxygen concentrator and how Inogen products work, read on to learn about the Inogen One G5, G4 or G3 Portable Oxygen Concentrators. You can also explore our Inogen One comparison chart to compare the features of each Inogen One model and get a quick idea of which model best meets your needs. If you prefer a stationary concentrator for your home, learn below about our stationary oxygen concentrator, the Inogen At Home.

Inogen One G5 Systems

The Inogen One G5 System is the latest technologically advanced innovation in portable oxygen delivery systems, offering 6 flow settings in one of the quietest, smallest, lightest and most powerful portable oxygen concentrator units available. Capable of delivering oxygen 24 hours a day, 7 days a week using our proprietary Intelligent Delivery Technology®, the G5 offers more flow settings and a significantly longer battery life—up to 13 hours (with a double battery)—than other models. Nonetheless, the Inogen One G5 is small and easy to carry, weighing only 4.7 pounds, allowing you to travel with ease and without needing to recharge as frequently. Including the convenience of the Inogen Connect App with Bluetooth System, the Inogen One G5 helps you monitor your oxygen use and keep track of your equipment’s functionality on any supported device. You can travel and enjoy oxygen anytime, anywhere with the G5 as it meets FAA requirements and is easy to bring with you on any trip. You will receive a 3-year warranty and a custom carry bag for your G5, along with a single battery, DC power cable and AC power supply. Purchase a Freedom Package to enjoy everything listed, as well as a lifetime warranty, additional batteries and the freedom of worry-free use.

Inogen One G4 Systems

 Designed to be remarkably small, the Inogen One G4 portable oxygen concentrator is one of the lightest and quietest units available for oxygen therapy today. Weighing only 2.8 pounds, this portable oxygen concentrator is easy to take with you, wherever you go. It offers 1-3 flow settings, using our proprietary Intelligent Delivery Technology®, ensuring that oxygen therapy is delivered effectively and efficiently in all modes of use, whether users are asleep, at rest or exerting themselves. The Inogen One G4 System also includes a Bluetooth System and with the Inogen Connect App, it helps you monitor your oxygen use and your Inogen One System through any supported device. Additionally, you will receive a carry bag, user manual, AC/DC power supplies and your single rechargeable battery with a life of up to 2.7 hours with the standard battery. Your Inogen One G4 System meets FAA requirements and is covered by a standard 3-year warranty. However, if you choose to purchase one of our three Freedom Packages, you will receive everything listed above, as well as additional batteries and a lifetime warranty, freeing you from worry. 

 Inogen One G3 Systems

The Inogen One G3 portable concentrator allows you to enjoy oxygen anytime, anywhere, even while you travel. This model provides 5 flow settings and infinite oxygen as long as the concentrator has power. It is lightweight, weighing 4.8 pounds, and provides the quiet energy efficiency and easy operation of all Inogen oxygen concentrators. The Inogen One uses our proprietary Intelligent Delivery Technology® to ensure that oxygen therapy is delivered efficiently and effectively in each mode of use, oxygenating patients whether they are exerting themselves, at rest or asleep. The Inogen One G3 System comes with the G3 concentrator, a single rechargeable battery with a life of up to 10 hours, AC/DC power supplies, a user manual and a carry bag. The Inogen One G3 System also meets FAA requirements and is covered by a standard 3-year warranty. To receive a lifetime warranty and additional batteries, purchase one of the three Freedom Packages and free yourself from concern about running out of power or other issues. 

 Inogen At Home

 The Inogen At Home is our stationary oxygen concentrator. One of the most energy-efficient, lightweight stationary oxygen concentrators available, the Inogen At Home weighs 18 pounds—half the weight of many other home oxygen concentrators currently being used. The Inogen At Home is energy-efficient, using just 100-watts of energy on Flow Setting 2 and saving you money on your electricity bill. Even better, although this oxygen concentrator provides you with 5 liters per minute continuous flow oxygen, it is extremely quiet. If you need a stationary oxygen concentrator, try Inogen’s At Home oxygen concentrator for your oxygen therapy.

Frequently Asked Questions

How does the Inogen One make oxygen?

Inogen One portable oxygen concentrators do not actually make oxygen. Rather, they pull oxygen from the air surrounding them and concentrate it. To do this, Inogen One Portable Oxygen Concentrators remove nitrogen and other gases, as well as impurities, found in the air to purify it and compress it into medical-grade oxygen. Once the oxygen is sufficiently purifying and concentrated, the Inogen One produces oxygen-rich air, which is then delivered to the user via nasal cannula.

How does an oxygen concentrator work with the surrounding air?

The way an oxygen concentrator works is surprisingly simple. It uses the surrounding atmosphere to create oxygen-rich air by pulling surrounding air into the oxygen machine, compressing it, purifying it and removing nitrogen and other impurities. The purified, oxygen-rich air is then delivered to the patient. 

How does a portable oxygen concentrator work without running out of oxygen?

While an oxygen concentrator does not truly generate oxygen on its own, the oxygen is pulled from the air around the oxygen generator. Because of this, there is no danger of running out of oxygen, as long as your oxygen machine has power and access to open air. Simply ensure that you always have a clear air supply, a powered battery and access to a power source, and you can enjoy an endless supply of oxygen from your 02 concentrator. 

Can you use a portable oxygen concentrator while you sleep?

Many portable oxygen concentrators are made to be used anytime you need supplemental oxygen. Inogen portable oxygen concentrators incorporate our proprietary Intelligent Delivery Technology® to ensure that oxygen therapy is delivered effectively and efficiently in all modes of use, whether you are exercising, at rest or sleeping. Because your respiratory rates change with your level of activity, each of our Inogen One models responds to your changing physiology by detecting your breathing rate and adjusting the bolus dose. The Inogen One system is clinically proven to effectively deliver the oxygen you need, no matter what time of day it is. 

What is an oxygen concentrator’s maintenance needs?

While an oxygen concentrator does not require refills or tank replacements like other oxygen delivery systems, it is important to make sure you keep up with your O2 concentrator’s maintenance needs to ensure that your oxygen machine is operating correctly. Proper maintenance also ensures that your portable oxygen concentrator lasts so you can use it for as long as possible. Alarms will typically let you know when replacement parts are required, but it is a good idea to know what to look for before you experience any problems with your oxygen generator. Read your model’s manual for more information, but for general maintenance, you should:

  • Wipe down your oxygen generator once a week to keep it clean from dirt, dust, hair or pet fur
  • Check your particle filters weekly and rinse clean when dirty
  • Change your nasal cannula and tubing regularly, as directed by your provider
  • Inspect HEPA filters and columns (sieve beds) to see if they require changing or replacement
  • Heed all alarms 

Where can I get replacement parts for my oxygen concentrator?

Inogen offers replacement parts and accessories conveniently on our website. You can order some of the parts ahead of time to keep them on hand, or choose to order as needed. As always, if you have any questions about installing replacement parts, which parts to purchase or any other questions about how to use a portable oxygen concentrator, we are here to help. Contact us for help and information. 


“Oxygen Delivery Devices: Intelligent Delivery.” Inogen, Inogen Inc., 5 Mar. 2019,

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