How Does an Oxygen Concentrator Work? [Detailed Guide]

How Does an Oxygen Concentrator Work? [Detailed Guide]

One of the most commonly utilized medical devices today is the oxygen concentrator. It is often used to aid people with trouble breathing due to several health conditions, including lung cancer, flu, asthma, and COVID-19.

If you have these problems, your doctor can prescribe one for you, and this post will show you how an oxygen concentrator works.

In this article you'll learn:

  • How an oxygen concentrator works
  • Tips for using an oxygen concentrator
  • The 5 steps of the oxygen concentration process
  • Who should use an oxygen concentrator and when
  • The different types of oxygen concentrators
  • How oxygen concentrators differ from oxygen cylinders and LMO
  • Things to consider before buying an oxygen concentrator
  • If portable oxygen concentrators good for day and night

How Does An Oxygen Concentrator Work?

In the simplest terms, oxygen concentrators work by concentrating and filtering oxygen molecules through a device. They take the ambient air to process so that patients can have up to 90% to 95% pure oxygen. Then, the compressed air is dispersed through an oxygen mask or a nasal cannula.

There are also available portable oxygen concentrators that you can use at home or even when traveling. However, without a proper prescription from a doctor, doing so can do you more harm than any good. If you want to know more about this device, keep on reading.

What Is An Oxygen Concentrator?

An oxygen concentrator works to support and provide patients with breathing problems with supplemental oxygen. The device itself consists of the following items:

  • Compressor
  • Product tank
  • Pressure valve
  • Sieve bed filter
  • Nasal cannula (oxygen mask)

Like oxygen tanks, the processed air is supplied through a nasal tube inserted on the nose. It can continuously provide oxygen for 24 hours without refilling, unlike oxygen cylinders. One oxygen concentrator can provide 5 to 10 liters per minute of purified oxygen. 

What differentiates concentrators from oxer oxygen supplying containers is their use of electrical pumps to separate the oxygen and nitrogen from the air. Aside from aiding breathing issues, this device is also particularly helpful in oxygen therapy

If you think you need this device to help with your existing problems, do not purchase it online without a proper prescription. There is no FDA approval yet for oxygen concentrators to be distributed without a doctor’s consent.

Tips for Using Oxygen Concentrators

In addition to that, you should remember the following when working with an oxygen concentrator:

  • Place the device in an open space to avoid overheating
  • Avoid blocking the vents of the concentrator to utilize the device’s full use
  • Do not use the device near a smoking area or an open fire
  • Regularly check the concentrator for issues and problems

Keep in mind that you should not make any changes to the level of oxygen yourself and call your health provider for immediate assistance. 

How Exactly Does Oxygen Concentrator Work?

How Does an Oxygen Concentrator Work? finger pressing O2 concentrator

Oxygen concentrators process the air of their surroundings, then filter out the Nitrogen to supply up to 95% medical oxygen. It has two sieve beds made of Zeolite, a crystalline material responsible for filtering out Nitrogen. 

The air that we naturally breathe is composed of different glasses, and oxygen is only one of them. It is estimated that there is at least 21% of oxygen in the ambient air, 78% of that is Nitrogen, and the remaining 1% is other gasses.

The primary job of an oxygen concentrator is to separate these gasses and use the principle of Pressure Swing Absorption (PSA) to deliver quality oxygen.

5 Steps Of The Oxygen Concentration Process

For you to understand how this machine works, you have to take a deeper look into its functions. Overall, there are a total of five steps of the concentration process, and it is as follows:

1. Taking air from the area

First, the ambient air, or the air within an area, that passes through the device’s filters, is attracted by the compressor. 

2. Compresses the oxygen

The air is then compressed in one of the two molecular sieve beds while all of the Nitrogen is absorbed. Sieve beds can absorb large amounts of Nitrogen and are to be changed only by professionals when they become overly saturated or damaged.

The concentration comes up with up to 95% of oxygen through the process. It will then be ready to supply the patient using an oxygen mask or nasal cannula. 

3. Separates nitrogen from oxygen

As the first sieve gets saturated, the switch valve will then put the action to the second sieve bed to continue the process. The Nitrogen on the saturated molecular sieve bed will then be vented out of the machine, while the remaining is to be removed through back-flushing from the other sieve bed.

4. Adjusts the flow of oxygen as it is being delivered

After this, the switch valve will switch to the first sieve bed once again when the second sieve bed nears its saturation. It is all a repeating process, and the purpose of this is to ensure a continuous flow of oxygen inside. This is called Pressure Swing Absorption (PSA).

5. Delivers oxygen to the patient

Once the oxygen is ready to be let out, the flowmeter controls the flow. The set liter per minute depends on what the patient needs. For example, patients with asthma require more than 6 liters per minute, while COVID patients need an oxygen flow of at least 5 liters per minute. 

Oxygen Concentrator Parts

Much like any other machine, an oxygen concentrator is composed of different parts. To further understand how this device works, here are its components alongside their roles:

  • Filters – This filters out impurities and pollution present in the air.
  • Air compressor – This pushes the air to the device and transports it to the sieve beds.
  • Switch valve – This is used to switch the compressor output of the sieve beds
  • Oxygen outlet – This can be in the form of a mask or a nasal tube. It is used to transport the product directly to the patient.
  • Two molecular sieve beds – Traps Nitrogen and releases it back to the room; made of Zeolite.
  • Flowmeter – Used to set the flow of liters per minute (LPM)

Who Should Use An Oxygen Concentrator And When?

Generally, everyone can use oxygen concentrators. It is primarily safe for children to seniors, but only if they are experiencing oxygen saturation levels of 90% to 94%. Doctors recommend that only mild to moderately ill patients be prescribed this under professional guidance.

On the other hand, those with as low as 85% saturation may use this device in emergencies. However, they must go to the nearest hospital as soon as possible to be assessed, get admitted, then switch to cylinders with higher oxygen flow. Oxygen concentrators are not advisable to use among ICU patients. 

What Are The Different Types Of Oxygen Concentrators?

When it comes to oxygen therapy, there are two types of concentrators that you should consider: Continuous flow (CF) and Pulse Dose (PD). 

Continuous flow

This type of oxygen concentrator provides the same flow every minute, given the device is well-tended and the patient is breathing oxygen as they should. In continuous flow portable oxygen concentrators, the flow of Oxygen is constant no matter the user’s breathing pattern. The downside of this is the amount of oxygen that is being wasted.

Pulse dose

On the other hand, this type of concentrator is smart and can detect the pattern in which a patient breathes and releases oxygen following that. The flow of oxygen varies per minute on this one and is entirely customized by the person’s inhaling rate.

Between the two, pulse dose is the better option. Its mechanisms are more prone to conserve oxygen and relate to the user’s breathing patterns and other factors. It can also deliver the right amount of oxygen needed for various daily activities. 

How Are Oxygen Concentrators Different From Oxygen Cylinders And LMO?

Oxygen concentrators are only one of the devices that can provide pure oxygen to those in need. However, cylinders and liquid medical oxygen are difficult to transport and store, making concentrators a great alternative.

Comparatively, concentrators are more expensive than the rest, but that is primarily influenced by their one-time payment, portability, and low operational cost in the long run. Cylinders require constant refilling, while concentrators can provide oxygen for 24 hours through the electricity supply and the ambient air surrounding the machine. 

However, there is a drawback with this device as well. They are not entirely beneficial for patients with critical conditions as they require around 40 to 45 liters of oxygen per minute, while concentrators can also provide about 5 to 10 liters per minute. 

Read more: Comparison of Oxygen Concentrator Vs Oxygen Tank

3 Things To Consider Before Buying An Oxygen Concentrator

Let’s suppose you fully understand how does oxygen concentrator work and decide you need one right now. Aside from choosing an affordable oxygen concentrator that fits your budget and medical needs, these are the factors that you should consider first before making a deal:

1. Oxygen concentration

Before buying a concentrator, the most crucial factor you must consider is its oxygen concentration. There is a specific percentage of purified oxygen a patient needs to function. The concentration of oxygen may be influenced by the machine’s design and filtration system.

Low-quality molecular sieve systems will also be less effective and not provide the necessary amounts of oxygen the user needs. Be sure that the concentration level is within 87% to 99% to be deemed effective.

Read more: How much Oxygen does a portable oxygen concentrator produce?

2. Flow rate

Another thing to consider is the flow rate. If the patient requires higher oxygen flow rates, then choosing the one that can provide higher concentrations is the better choice. However, if the user doesn’t necessarily need high oxygen concentrations, then portable concentrators are fine.


It is also necessary to consider how mobile you want your concentrator to be. This device is available in various sizes.

While higher-powered models can provide higher flow rates, they might not be the best to bring everywhere you go. They are primarily for home use, where there is no need for constant moving.

If you prefer portable devices, there is a wide selection available as well. They tend to weigh around 10lbs, which are easier to bring anywhere. However, they might not be able to support patients who need higher flow rates.

We made a comprehensive guide on how to choose a portable oxygen concentrator. Be sure to check it out.

Are Portable Oxygen Concentrators Good for Day and Night?

Most home use oxygen concentrators can run for as long as 24 hours, but that doesn’t necessarily mean you need that. It is okay to use oxygen concentrators while sleeping for people with breathing problems who constantly suffer from a lack of oxygen at night.

Using a concentrator during the day is okay because you can regulate the flow rate. During the night, it is generally safe, but giving yourself too much oxygen can be harmful. It would be the safest to consult a doctor regarding this matter since everyone’s cases are different.

Where to buy affordable, top-quality oxygen concentrators?

There is power in knowing how does an oxygen concentrator work, especially if you are suffering from breathing issues. You can do many things to ease this problem, but be sure to consult your doctors before making any significant decisions regarding your health.

If you’re looking for a stationary or portable oxygen concentrator for sale, don’t hesitate to browse our collection, or call us at (800) 314-8225.

How Does an Oxygen Concentrator Work Sprylyfe infographic

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