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What is an Oxygen Concentrator and How Does It Work? (Uses and Reasons)

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oxygen concentrator

Thanks to the field of medicine’s great advancements, the oxygen concentrators today are compact, small, quiet and lightweight, but still provide the utmost compliance and high performance. Older oxygen concentrators are bulky and heavy, making it difficult for patients requiring oxygen therapy while traveling or outside their home.

Today, you can choose from at-home stationary concentrators and portable oxygen concentrators (POCs), which can go wherever you go easily.

What is an Oxygen Concentrator?

Oxygen concentrator definition: An oxygen concentrator is a type of medical device used for delivering oxygen to individuals with breathing-related disorders. Individuals whose oxygen concentration in their blood is lower than normal often require an oxygen concentrator to replace that oxygen.

Generally, you can’t buy an oxygen concentrator over the counter. A doctor must prescribe it after they’ve completed a thorough medical evaluation. The doctors will also typically show the patients how to effectively use these concentrators while traveling and in their homes.

Oxygen concentrators filter surrounding air, compressing it to the required density and then delivering purified medical grade oxygen into a pulse-dose delivery system or continuous stream system to the patient.

It’s also equipped with special filters and sieve beds which help remove Nitrogen from the air to ensure delivery of completely purified oxygen to the patient. These devices also come with an electronic user interface so you can adjust the levels of oxygen concentration and delivery settings. You then inhale the oxygen through the nasal cannula or special mask.

You generally measure the oxygen concentrator output in LPM (liters per minute). Your doctor will determine what level of oxygen you need, which may vary at rest, during sleep, and when you exercise.

What are the Uses and Reasons for an Oxygen Concentrator?

There are many reasons for an oxygen concentrator and doctors can recommend oxygen therapy to their patients for various medical conditions. Typically, your lungs absorb the air’s oxygen, transferring it into your bloodstream.

If you’ve had bloodwork or pulse oximetry recently performed to assess your oxygen saturation levels, and you were found to have low levels of blood oxygen, your doctor may recommend short-term or long-term oxygen therapy.

You’re probably wondering what is an oxygen concentrator used for? Acute conditions usually require short-term oxygen therapy. These conditions normally run for a short period of time. They may have a sudden onset of symptoms versus chronic conditions where things occur gradually. However, some respiratory or chronic conditions require long-term oxygen supplementation.

Acute Conditions Requiring an Oxygen Concentrator

A few examples of acute conditions where you would need the use of an oxygen concentrator for short-term oxygen therapy are:

Asthma: This condition is where your airways become inflamed and begin producing a lot of mucus, which makes it harder to breathe. While there are a number of pharmaceuticals that can treat and control asthma, an oxygen concentrator can pump high levels of oxygen into the bloodstream of the patient while they’re having or have already had an asthma attack.

Pneumonia: Pneumonia is an infection where you develop inflammation in either one or both of your lungs’ air sacs and in many cases, fill them up with fluid. Many pneumonia patients have been prescribed oxygen therapy and have seen good clinical outcomes.

Respiratory distress syndrome (RDS): RDS is a breathing disorder mostly affecting newborns, particularly those who are born six or more weeks before their delivery date. Newborns suffering from RDS don’t create enough surfactant (a lung coating liquid), causing their lungs to collapse and making them work harder to breathe. Oxygen therapy using oxygen concentrators help pump oxygen into the babies’ bloodstream and lungs to reduce further complications.

Bronchopulmonary dysplasia (BPD): Newborns suffering from RDS also have a higher risk of developing BPD. This is a severe lung condition requiring long-term breathing support.

In some cases, after surgery, you may need oxygen for a short period of time.

Chronic Diseases that Require Oxygen Therapy

Some chronic conditions requiring long-term oxygen concentrator uses are:

Chronic obstructive pulmonary disease (COPD): COPD affects around 16 million people, but an oxygen concentrator can be an effective treatment. When you have COPD, you have chronic lung damage which makes it difficult for your lungs to absorb enough oxygen. As a result, you can have difficulty breathing, and oxygen therapy through a concentrator can help.

Cystic fibrosis: You inherit this life-threatening condition. It causes digestive system and lung damage. It’s a rare condition that affects the body’s cells responsible for producing mucus, sweat, and digestive juices. The fluids are changed which results in a stickier, thicker solution that plugs the ducts, tubes, and passageways of the individual infected.

Sleep Apnea: Sleep apnea is a sleeping disorder that can be serious and cause the individual’s breathing to sporadically stop and start during their sleep. Usually, treatment for this condition is continuous positive airway pressure (CPAP), weight loss, and physical exercise, though some people with sleep apnea may require oxygen therapy.

How Does an Oxygen Concentrator Work?

Think of an oxygen concentrator as a window air conditioner — it takes air in, changes it, and delivers it in a different form. The oxygen concentrator takes air in and purifies it for use by individuals who require medical oxygen because of low levels of oxygen in their blood.

It works by:

  1. Compressing air as the cooling mechanism keeps the concentrator from becoming overheated
  2. Taking air in from its surroundings
  3. Using an electronic interface to adjust delivery settings
  4. Removing nitrogen from the air through sieve beds and a filter
  5. Delivering purified oxygen through a mask or nasal cannula

Patients who required oxygen therapy in the past mainly relied on pressurized oxygen tanks. Even though these tanks are extremely effective, they’re also fairly inefficient with the suppliers having to visit the patients regularly to replenish their oxygen supply in their tank.


Learn more about the different oxygen concentrators available to you from CPAP.com:

1. Philips Respironics SimplyGo Mini Portable Oxygen Concentrator with Pulse Dose Flow – A travel-friendly oxygen concentrator with accessories and features specifically for the active lifestyle. It provides a pulse dose flow, helping to extend its battery life.

2. Philips Respironics SimplyGo Portable Oxygen Concentrator with Pulse Dose and Continuous Flow – This is a portable concentrator for individuals who wish to bring along their oxygen therapy with them while performing their daily activities. It provides pulse dose and continuous flow modes for extra versatility.

3. Inogen One G4 Portable Oxygen Concentrator with Pulse Dose Flow – The Inogen One G4 makes its own oxygen supply using the air surrounding it. It’s today’s most portable oxygen concentrator and is light and small enough to carry it like a tote bag or purse. It even has a shoulder strap connected to the device directly.

4. Inogen One G3 Portable Oxygen Concentrator with Pulse Dose Flow – A compact oxygen concentrator made for providing pulse dose oxygen on the go or at home. It weighs 4.8 pounds, making it perfect for traveling.

5. Inogen At Home Stationary Oxygen Concentrator with Continuous Flow – An oxygen concentrator providing high continuous oxygen levels for home use. It’s one of the more compact, lighter stationary concentrators around and provides one to five liters per minute continuous flow.

6. ResMed Activox™ Portable Oxygen Concentrator with Pulse Dose Flow – A portable oxygen concentrator that’s versatile and perfect for the active user. It has an internal battery so you can unplug the concentrator and take it wherever you go.

You’ll first want to have your doctor or sleep professional give you a full evaluation to determine if a portable or stationary oxygen concentrator is ideal for your needs.

  • David Repasky

    David Repasky has been using CPAP treatment since 2017 and has first-hand experience with what it's like to live with Sleep Apnea. He brings the patient's perspective to the CPAP.com blog and has received formal training in CPAP machines, masks, and equipment.

Need Help With Sleep Apnea?

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25 Responses

  1. I don’t need oxygen all the time. I’m usually at 90-92.. but then when I use oxygen it only goes up 93-94…my question is, is this normal?

    1. Hi Jacquelynn, it really depends on which concentrator is being used. Some concentrators have a reusable filter that should be cleaned and over time may need to be replaced. Please provide the name of the concentrator in question and I will confirm for you if and when the filter should be changed.

      Please feel free to reach us at: 1-800-356-5221, ask for Carol, or you may e-mail me the information at: cpap@cpap.com, Attn: Carol.

      Enjoy your day!

  2. //what causes your nose to run a lot – I use a concentrator with a water bottle attached and I use a nose

    1. Hi Alice,

      Sorry to hear about the problems with a runny nose. Have you spoken with your doctor? If not, please do since the problem your having could be related to allergies.

      Also, you may consider switching to a cannula, that is shorter, with wider prongs. Not sure if this will help, but it’s worth a try!

      One patient recommends this: Salter Labs ref. 1600-7 with 7ft tubing

      For further questions, or concerns, please feel free to reach us at: 1-800-356-5221, or you may e-mail us at; cpap@cpap.com.

      Have a great weekend!

  3. Which machine would be the best if we got the corona 19 virus,and had a bad time of breathing,raspy cough?Thanks

    1. Hi Ken and Linda,
      I would recommend you speaking with your health care provider, for guidance on which machine may best fit your needs.

      I’m sorry we aren’t able to answer your question, if you think of anything else we may be able to assist you with, please reach us at: 1-800-356-5221, or you may e-mail us at: cpap@cpap.com.

      Best Wishes!

  4. Some of us, but obviously not all of us, are technically inclined and like to know how things work. I am one of them. Like many people, but obviously not all, I would like to know what the output of O2 concentrators is. Is it 30% O2, 50% O2, 90% O2, or what? And EXACTLY how do they work?

    It seems to me that, for those of us who are interested, you could have a page on your web site to explain all those details in a way that makes sense and is not watered down. People who are interested would read it and people who are not interested would not read it. But please consider those of us who are well educated, are interested in the world, and really like to know how thing work whether it is nuclear reactors, anti-lock brakes, or O2 concentrators.

    1. That’s what I came here looking for too. I eventually found the answer on another site. Dry air is about 4/5 nitrogen and 1/5 oxygen, with small amounts of other things (like argon and carbon dioxide). So if you could get rid of the nitrogen what would be left is mostly oxygen.

      It seems they use two tanks filled with zeolite, a very porous aluminosilicate mineral. The particular zeolite used preferentially absorbs (technically aDsorbs) nitrogen. So they pressurize one of the tanks, most of the nitrogen gets trapped by the zeolite, and then a valve opens to release the rest of the air (which as stated above is mostly oxygen) into a different holding tank. Meanwhile, the compressor switches to the second zeolite tank and starts compressing air into it.

      Midway through while the second tank is filling/pressurizing, the pressure in the first tank drops to the point where the nitrogen starts coming back out of the zeolite. The valve to the holding tank is closed, and a separate exhaust valve opens. That releases the now nitrogen-rich contents back into the air, so the first tank is ready for another cycle. The process then switches between which of the two tanks is being pressurized and which is being vented into the holding tank/atmosphere. Search for “pressure swing adsorption” if you want more details than that.

      Apparently this cycle lets them get somewhere in the vicinity of 90% oxygen in the holding tank (with the rest being mostly argon, carbon dioxide, and water vapor, along with some nitrogen that came back out of the zeolite when the pressure dropped).

      The zeolite is reusable indefinitely, though it seems possible that it could lose its effectiveness over time due to getting “clogged up”. Presumably that’s what the filters are for: to keep dust, pollen, and other large stuff that might clog the zeolite pores out of the zeolite tanks.

  5. I agree with Frank Eggers – it would be great to have a tech page that explains exactly how O2 concentrator work & the percentage of O2 delivered !

  6. Are there any machines that I can use with my cpap machine? According to the Inogen website, I cannot use my cpap with their machines.

  7. I have a CPAP machine and a oxygen generator. I have combined both machines through a (y-pipe and mask) so I get c-pap positive air with extra oxygen. It works well. Is there any danger involved? Thanks, Norm

    1. Hi Norm, my apologies, but i’m not familiar with the process for using a y-pipe since we don’t carry this product. I’m therefore, not able to confirm if there is any danger involved. We usually, recommend our customers use an Oxygen Enrichment Adapter to use Oxygen, in conjunction with their CPAP therapy. To view this product please see the link below.


      For further questions, or concerns, please feel free to reach us at: 1-800-356-5221, or you may e-mail us at: cpap@cpap.com.

      Have a great weekend!

  8. You got any dealers or distributors in Kerala.
    If there is no any other distributors in kerals , I am interested to know more about your products and market it in Kerala.

    1. Hi John, my apologies, but we don’t have any dealers in Kerala. We have one location in Texas, but if you are interested in placing an order, we can ship the order to you.

      If you have specific questions regarding any of our products, please feel free to contact us at: 1-800-356-5221, or you may e-mail us at: cpap@cpap.com.

      Have a great day!

    1. Hi Jagdish, my apologies, but we have only one location in Texas (U.S.). You can place an order online, or over the phone and we are happy to ship to you in India.

      Please keep in mind that we are not able to ship any ResMed, or Philips Respironics, manufactured outside of the United States, but all other brands can be shipped.

      Please feel free to reach us at: 1-800-356-5221, or you may e-mail us at: cpap@cpap.com, visit our website to place an order at: cpap.com, or you may use our chat feature for immediate responses to your questions, or concerns.

      We hope to hear from you soon!

  9. Is there a safe way to use a portable oxygen concentrator during covid 19 times? I assume that the unit will not filter coronavirus droplets. A mask would be useless against the virus if you are getting your air through the cannula. What do we do?

    1. Hi Carolyn, since the oxygen concentrator is simply circulating the air from the space you’re in and concentrating it, I cannot assure it’s safe to use your portable concentrator outside your home.

      You may consider exploring the possibility of adding an inline bacteria filter which has the potential to kill some viruses. Otherwise, I would recommend, you speaking with your doctor to receive his/her medical guidance on the safeness for using your portable concentrator away from home.

      For further questions, or concerns, please feel free to reach us at: 1-800-356-5221, or you may email us at: cpap@cpap.com.

      Stay safe!

  10. I recently replaced my wife’s columns in her oxygen home concentrater. I took one of the old tubes apart and found some kind of material in the column.
    What is the material in what is called the sieve beds ? How does this material remove nitrogen?

    Mark Hardison

    1. Hey Mark, this information is better provided by the manufacturer of the unit you own. I’m happy to help point you in the right direction if you would like to provide me with the make and model of your unit.

      We can be reached at: 1-800-356-5221, or via email at: cpap@cpap.com.

      Enjoy your day!

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