The 5 Best Oxygen Concentrators 2021 – Reviews Buyer’s Guide

Oxygen concentrators help patients suffering from pulmonary distress to have a better quality of life. If you want to buy a portable oxygen concentrator, but find the product specifications a bit confusing, don’t worry. We are here to help you. You have come to the right place. In the following paragraphs, we’ll show you some of the best mobile oxygen machines you can find.

Our Top Pick

10 Best Oxygen Concentrator Review

SaleBestseller No. 1
Entair OXICON-5000 Ultra Silence Oxygen Concentrator - 5 L (White)
  • With 3 handles and 4 wheels
  • It goes with whichever alarm is required to remind the visual or hearing impaired user of situations that require a quick response to ensure the safety
  • 1.Flow rate0: 5L/min
SaleBestseller No. 2
Owgels 1-5 Liter Portable Oxygen Generator Oxygen Concentrator Machine
  • Owgels Oxygen Concentrator machine converts the surrounding air into pure oxygen that is ready to breathe.
  • This machine can produce oxygen from 1 liter to 5 liters per minute (continuous flow setting).
  • Equipped with a humidifier bottle, oxygen hose, nebulizer and air filter.
  • he O2 (Oxygen) produced is very clean.
SaleBestseller No. 3
XElectron Portable Oxygen Concentrator 1-6 Liter Per Minute 93% Oxygen Purity
  • 【1-6L Oxygen flow adjustable】1L/m: 93% Oxygen Purity; 2L/m: 80%; 3L/m: 70%; 4L/m: 60%; 5L/m: 50%; 6L/m: 45%; HD LED Touch screen easy to read and remote control by far infrared.
  • 【≤48dB Quiet】 The Oxygen machine is very low noise, less than 45dB, night use will not affect sleep, It works with or without water, no need to refill at night.
  • 【Anion Function and Timing Function】 Built-in high frequency negative ion generator, The machine is equipped with a timing function (4 hours).
  • 【AC power 220V】Power supply:220V±10%, 50Hz|Input Power: 130VA (not battery powered), It can work 48 hours nonstop.
  • 【Portable Design】 Outline size: 30.2cm*16.8cm*32.5cm|Weight: 5.6Kg|Easy to move with convenient handle.
SaleBestseller No. 4
Yuwell YU300 Homecare Oxygen Concentrator
  • Provides oxygen at 30 - 90 percent concentration based on flow rate from 1 - 5 LPM
  • Built-in compact humidifier and timer function up to 30 minutes
  • Operating noise is less than 43 DB and net weight is 7.5 Kg
  • Stability: Able to operate for 48 hours without fail while others couldn't last more than 12 hours
  • Ultra Silent, Easy Shuttle, Intelligent Surveillance, High Reverse Display LCD Screen, Detachable Filter and Infrared Remote Control System
SaleBestseller No. 5
OWGELS[German Brand]| 5L Moveable Hospital Use Oxygen concentrator, a safer, less expensive, and more convenient live saver and homecare medical equipment(Every order comes with FREE surgical masks)
  • ● ✅ GERMAN BRAND OXYGEN CONCENTRATOR: With 390VA power consumption, this device is designed for providing a continuous flow of oxygen conveniently both at hospital and at home. It fulfills a patient’s clinical needs to maintain quality-of-life and independence.
  • ● ✅INTENDED MEDICAL USE : Pumps high-level oxygen into the bloodstream of patients who have developed inflammation in airways. Mostly prescribed for Pneumonia, Asthma, RDS, and BPD patients to reduce breathing-related complications.
  • ● ✅HIGHEST OXYGEN PURITY : It separates oxygen from ambient air and removes impurities to produces concentrated oxygen. Just after turning ON for 30 minutes, it can deliver up to 5 LMP (93%±3%) concentrated oxygen to alleviate breathing issues.
  • ● ✅EASIER & SAFER METHOD : There are no confusing electronic controls to operate the unit easily. Equipped with Transom Filter, Intake Filter, Humidifier, Oxygen Tube, Power Cord, Power Switch, Safety Valve, and all other needed parts to ensure the delivery of purified oxygen safely.
  • ● ✅INTELLIGENT TECHNOLOGY : Digital LCD display indicates flow rate, oxygen concentration, and time. Through its intelligent electronic user interface, the levels of oxygen concentration and delivery settings can be adjusted easily as per your convenience.
SaleBestseller No. 6
CARER® 5 Litre Oxygen Concentrator | Model: CR-P5W | Adjustable Oxygen Flow 0.5-5 L/min
  • Italian HEPA Filter - Filter 99.99% of particles above 0.3 microns, which is far better than common international standards PM2.5(that is 2.5 microns). Helpful to avoid bacterial infections
  • Molecular Sieve Imported from USA - World-class sieve helps using air as raw material to separate oxygen and nitrogen by PSA
  • Wireless Remote Control - Control the concentrator with ease using the included remote control
  • Fault Detection Function - If machine encounters an error, it is equipped to automatically detect it and sound an alarm so that safety is never compromised
  • Efficient Oil-Free Compressor - Oil-free compressor adopts pure copper core compressor, which is stable and reliable. Provides surging power for continuous use of the machine and enhances service life
SaleBestseller No. 7
Medical Grade Oxygen Concentrator Machine for Oxygen Supply 0 – 5L/min. Affordable Portable Up to 95% Oxygen Purity for Home use Oxygen Concentration Device Oxygen Supply for COVID-19 Patients
  • This is a compact and light-weight Oxygen Concentrator with 5 Liters/minute capacity. Purity of Oxygen is above 95% even at 5 Liters/minute flow rate.
  • Net Weight: 15.5 Kg, Sieve Beds will have a service life of around 7500 -9000 hours depending on environmental conditions.
  • Power Supply 220V/50Hz | Input Power 400VA Noise level is less than 52dB | Output Pressure 40-70Kpa | Oxygen Output 0-5L/min.
  • It has a built-in LCD display with timer function. This model features a self-diagnosis system and comes with multiple safety alarms. Oxygen failure alarm - continuously monitors quality of oxygen generated. Power failure alarm - audio alarm will alert attendant in case of power failure. High & low pressure alarm. Auto cutoff for over-heating.
  • Easy to clean air inlet filter. The precision compressor is made with German technology and has a service life of over 30,000 hours.
SaleBestseller No. 8
NOYMI | 5L 93% Oxygen Purity Medical Home Use Oxygen Concentrator Machine 5 Liter Oxygen Generator Concentrador
  • Low Noise Create a comfortable environment for you
  • Built-in compact humidifier and timer function
  • Health care oxygen therapy new upgrade
  • High Concentration Oxygen Generator
  • Oxygen Concentrator does not need to be replaced or refilled with anything
SaleBestseller No. 9
MSL Original 5 Litre (Machine Weight-20 kg) oxygen concentrator/oxygen generator 5LPM
  • . As the purity of oxygen dips at high flow rate then you are inhaling just air not pure oxygen). Oxygen concentration should be above 90%. Our concentrator is Genuine 5litre per minute oxygen concentrator and can provide upto 93% pure oxygen at a flow rate of 5 litre per minute. (oxygen concentration 5 litres/min, 93 percent, +/- 3)
  • . Equipped with oxygen purity indicator- Which depicts the exact purity of oxygen flowing in percentage
  • . Digital flow meter showing the quantity of oxygen flowing per minute
  • . Long Life Compressor Designed For 10000 Hours Of Maintenance Free Use
  • . Almost soundless machine. Very simple to use. Equipped with caster wheel for easy movement.
SaleBestseller No. 10
Folee Oxygen Concentrator 5 Litres, ≥ 90% High Purity Oxygen Machine
  • Recommended maximum oxygen flow: 5L/min. Flow scope when the nominal pressure at the outlet is 7kPa: 0.5L/min~ 5L/min.
  • Oxygen concentration when the nominal pressure at the output is zero (achieve the required oxygen concentration level within 30 minutes of the initial startup): the oxygen yield is 0.5L/min to 3L/min, the oxygen concentration is ≥90%.
  • Apply 7kPa back pressure at the recommended maximum flow, the flow reaches accuracy of ± 10% to the indicated flow. Output pressure: 0.02MPa~0.07MPa
  • Maximum nebulization rate: ≥ 0.1mL / min (for model with nebulizer). Power supply voltage: 220V±22V/110V±11V, 50Hz/60Hz ±1Hz. Input power: 450VA
  • The oxygen concentrator with nebulizer is additionally provided with air pipe, nebulization medicine cup, nozzle or face mask.

How does an Oxygen Concentrator works?

An oxygen concentrator is a medical device that produces air rich in oxygen. It takes in ambient air and removed nitrogen from it to produce a stream of air that’s mostly oxygen. Air is made up of 78% nitrogen and 21% oxygen, with trace amounts of argon, carbon dioxide, ozone and other gases. An oxygen concentrator filters air by taking out nitrogen to provide an air supply containing 90-95% oxygen.

Oxygen concentrators are widely used in the healthcare sector. They are required for patients who have difficulty breathing normally, or have low oxygen in their blood. Oxygen concentrators do not use a readymade source of compressed oxygen like an oxygen tank. Rather, they take in air, change its concentration, and give out oxygen-enriched air.

The Science behind Oxygen Concentration

An oxygen concentrator runs on electric power, either through a wall socket or a battery. If it relies on a battery, the battery needs to be plugged in to a wall socket to ensure an undisrupted power supply. Since it is a medical gadget, an oxygen machine needs a prescription, and cannot be bought over the counter.

Now let us understand the science behind oxygen concentration, and what really happens inside a concentrator. As mentioned already, an oxygen concentrator is a device that filters ambient air to generate air with a high concentration of oxygen. This is achieved by drawing in air through a motor, compressing it, and passing it through a molecular sieve bed filter.

An oxygen concentrator typically contains, among other things, a motor/compressor, a heat exchanger, two cylinders containing zeolite sieve beds, a product tank, a pressure regulator and a few valves for regulating airflow. First, the motor/compressor compresses the inflowing air and feeds it to the filter. The filter then removes nitrogen by a process called Pressure Swing Adsorption (PSA).

PSA is a technique used in separation of a gas from a mixture of gases under pressure. The filters use a mineral named zeolite for adsorption of nitrogen. Zeolite has a large surface area, and is made up of millions and millions of porous microscopic cubes. The mineral only eliminated nitrogen, allowing the rest of the atmospheric gases to pass through untouched.

When air passes through the filter beds at high pressure, zeolite adsorbs huge amounts of nitrogen due to its unique chemical nature and enhanced surface area. As a result, the outgoing air has a high concentration of oxygen. There are two stages to oxygen concentration. Air from the compressor first enters cylinder 1. A four-way selenoid valve regulates this part of the airflow.

The pressure inside the 1st cylinder is around 2.5 times that of normal atmospheric pressure. It facilitates rapid adsorption of nitrogen which leaves behind pure oxygen mixed with traces of other gases. This is the first stage of the concentration process and it takes about three seconds.

At the end of this stage, the oxygen-enriched air is channelized into the pressure-equalizing reservoir, also called product tank, and the incoming compressed air is directed towards cylinder 2 instead of 1.

As a result, pressure inside cylinder 1 drops which allows for desorption of nitrogen back into gas. In the second stage, there is another change in valve position, and the nitrogen-filled air from the 1st cylinder is released back into the atmosphere through a vent.

At the same time, oxygen-rich air leaves the reservoir and exits the machine though a flowmeter. The purified air is finally supplied to patients with the help of hoses, nasal masks and cannulas.

The pressure inside the hose is maintained by a pressure-regulating valve. A cooling system is also put in place to prevent the oxygen concentrator from overheating. This, in a nutshell, is how oxygen concentrators work. Oxygen machines can be of two types: fixed and portable.

Fixed oxygen machines need a wall socket, and hence, are not mobile. Portable devices can, however, be carried around, and are surprisingly easy to use. Let us now find out more about portable oxygen concentrators, how they work, and their uses.

Portable Oxygen Concentrators

A portable oxygen concentrator is an affordable source of on-the-go oxygen. It is a convenient alternative to cryogenic oxygen tanks that depend on a limited supply of compressed oxygen. A portable oxygen device typically has two settings: pulse dose and continuous flow. Pulse dose mode is suitable for daytime use. It delivers air through a cannula.

Machines with pulse dose mode are more compact and battery-efficient. Continuous mode is best suited for use during sleep. It supplies air through a tube and ensures a constant flow of air throughout the night. Portable oxygen machines are lightweight and easy to transport. They are permitted on public transport like trains, buses and ships.

Most devices are also approved by the United States Federal Aviation Administration (FAA) and can be carried onboard commercial aircrafts. However, users need to check with the airline they’re flying with if the brand and model of their oxygen concentrator is allowed on their flights.

In aircrafts without a pressurized cabin, a special kind of oxygen concentrator is needed which can deliver enough flowrate even at high altitudes. A portable oxygen concentrator is super flexible and can adapt to different modes of power supply. It can operate on a fixed power supply from a wall socket, be plugged into a car 12V D/C cigarette lighter, or be powered by a lithium ion battery.

Both fixed and portable machines have alarms to alert the user about power failure and sudden rise or fall in pressure. This helps them attend to the issue immediately and fix it at the earliest. In a portable machine, as in a fixed one, the purified air is delivered to the patient through a tube with either a cannula or mask fitted at its end. A cannula is a thin tube with two outlets that fits under the nose.

The patient breathes in the oxygen through the two vents that remain slightly inserted into the nostrils. The tube may be supported by loops around the ears and neck. While breathing through a cannula, a patient also breathes in the surrounding air as the nostrils are not fully covered.

In a mask, the area around the mouth and nose are fully covered and this helps provide a more concentrated supply of medical-grade oxygen. For travel purposes, of course, a cannula is more practical and comfortable to wear. It is easier to use and carry in the subway and streets than a full mask.

Portable oxygen concentrators produce anywhere between 1-5 liters of oxygen every minute. They ensure a continuous supply of oxygen as they use ambient air to produce oxygen-enriched air. They are great for mobile medical facilities like ambulances and mobile hospitals used in disaster relief.

Lightweight and Ergonomic

The primary selling point of the Caire FreeStyle Comfort is its size and weight. While there are many lightweight machines on the market, few are able to pack as much technology into such a small space. In fact, when people first see the device, they often don’t recognize it because the pictures make it look bigger than it really is.

The FreeStyle Comfort weighs in at just 5 pounds, about the weight of a milk jug. Additionally, the weight is distributed nicely making it even easier to carry. Whether you’re taking a quick trip to the grocery store or you’re taking an extended trip, you can have the FreeStyle Comfort at your side the whole time while hardly knowing it’s there. It even has an ergonomic curve to it that will keep it from moving around at your side as you walk.

Long Battery Life

There’s nothing worse than having your portable oxygen concentrator run out of juice while you’re on the go. This can throw a wrench in your plans and even put you in a dangerous situation. Fortunately, the Caire Comfort packs enough battery life to keep you going all day. With the single battery that comes with the device, you can expect to see up to 8 hours of battery life and with the double battery, you’ll have up to 16 hours of freedom! Below is a breakdown of battery life depending on your flow setting.

FreeStyle Comfort Battery Life

Flow SettingSingle BatteryDouble Battery
18 hours16 hours
24 hours8 hours
33 hours6 hours
42.25 hours4.5 hours
52 hours4 hours

High Oxygen Output

While there are many things that go into making a great oxygen concentrator, the most important by far is the amount of oxygen the machine can put out. 

The Caire Comfort offers flow settings 1 through 5 affording you ample options to customize your oxygen therapy according to your doctor’s specifications. If you are exercising or experiencing an exacerbation, the flow setting can be increased using the simple-to-use control panel. What’s more, Caire Inc. products like the FreeStyle Comfort come equipped with smart O2 technology which is a proprietary monitoring and O2 delivery feature that ensures proper oxygen delivery in more situations. Below is a breakdown of how this works.

autoSAT: This is a technology that ensures consistent bolus size by adjusting the motor speed with the patient’s breathing rate.

UltraSense®: The breath detection feature in the Caire FreeStyle Comfort is extremely sensitive and can detect even the most shallow breaths that may go unnoticed by other oxygen concentrators on the market.

autoDOSE: Rather than shutting off if no breath is detected like other devices would, the FreeStyle Comfort delivers auto doses in case the situation is critical.

Advanced Connectivity

While many people these days have a love-hate relationship with their smartphones, it’s hard to deny the benefits of staying connected wherever you are. Each FreeStyle Comfort unit is equipped with CaireVIEW™, a Bluetooth-enabled technology that allows you to track information such as your oxygen usage statistics and other information all from your smartphone, tablet, or computer.

CaireVIEW also offers telehealth technology that allows you to stay connected with your oxygen providers wherever you are in the world. From the smartphone app, you’ll be able to send data that will help your oxygen providers determine whether you are using your device as prescribed. You’ll also find a list of contacts that you can reach out to if you need assistance or troubleshooting.

Caire FreeStyle Comfort Specs

Weight5 Pounds
Dimensions10” H, 7.3” W, 3.1” D
Flow SettingsPulse Settings 1-5
Sound Level43 dBA @ Setting 2
Expected Battery LifeUp to 16 Hours (double battery)


If you are an individual needing a little extra room to breathe, selecting the right oxygen concentrator will greatly improve your quality of life by improving concentration, energy level, and overall mobility!

All five oxygen concentrators described in this review are excellent, but each has qualities that may better meet your unique needs.  

The main variables people consider are accurate oxygen sensing, easy-to-use controls, cost, size/portability, altitude height operation range, low noise level, low power consumption, and need for maintenance. 

In our group of five, all have safe methods to accurately deliver oxygen and easy to use controls. Power use, warranties, and maintenance needs were also closely ranked among our group. 

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