AirSep Portable Oxygen Concentrator Review

AirSep portable oxygen concentrators are discreet, light, and offer more independence than stationary oxygen units.

Jun 09, 2026

Expert Reviewed

Victoria LurieSenior WriterWritten by:
Donya CurrieNCOA Associate Director, CommunicationsEdited by:

Each AirSep portable oxygen concentrator weighs less than 10 pounds and delivers oxygen in a pulse-dose bolus, or a measured puff.
AirSep portable oxygen concentrators start at around $2,695.
You need a prescription to use supplemental oxygen.
AirSep is a division of CAIRE Oxygen.
The AirSep Focus is one of the smallest portable oxygen concentrators on the market.
While small portable oxygen concentrators are more discreet, they can’t deliver pulse-dose oxygen at the rates some people need.

We recommend products and services that offer real value to our readers. It's important to us that our reviews of portable oxygen concentrators are accurate, helpful, and trustworthy. So our team spent more than 1,000 hours researching and comparing options.

To choose what to recommend, we:

Researched 15+ brands and 30 models on our own
Spoke with experts in geriatric care and respiratory medicine
Mystery-shopped manufacturers and retailers to check product claims and see what the buying experience is like
Surveyed 300 oxygen machine users and caregivers to learn what matters most in real life
Reviewed medical and academic research on how well portable oxygen concentrators work and how safe they are
Looked at verified customer reviews on trusted sites like the Better Business Bureau and Trustpilot

Our review process is based on clinical evidence and expert input. So you can feel confident you’re getting reliable, up-to-date guidance. Learn more about our oxygen machine review methodology.

Receiving supplemental oxygen once meant staying at home and relying on a machine the size of a mini fridge. Now, portable oxygen concentrators help people with an oxygen prescription continue their lives. Today’s portable oxygen concentrators may help people who need supplemental oxygen maintain more flexibility.

Doctors prescribe oxygen for a range of conditions. COPD (chronic obstructive pulmonary disease) is often named as the main condition treated with supplemental oxygen. But portable oxygen may also help manage pulmonary fibrosis, sleep apnea, and COVID-related oxygen needs. One older adult we surveyed uses their portable oxygen to treat the effects of wildfire smoke.¹ People of any age can have a condition that requires supplemental oxygen, but research estimates Medicare provides 80% of America’s oxygen prescriptions.²

Portable oxygen concentrators can treat many conditions. But there are a limited number of companies that make the devices. CAIRE Oxygen, which has been in the oxygen business for 38 years, acquired AirSep in 2019. AirSep had early success with its LifeStyle portable oxygen concentrators. This AirSep oxygen concentrators review will explore the cost, noise level, and ease of use of AirSep’s three portable models. We'll also dive into what sets AirSep apart from other supplemental oxygen systems.

Comparing AirSep portable oxygen concentrators

Comparison Features	AirSep Focus Visit Sitefor AirSep Focus	AirSep FreeStyle 3 Visit Sitefor AirSep FreeStyle 3	AirSep FreeStyle 5 Visit Sitefor AirSep FreeStyle 5
Flow type	Pulse dose	Pulse dose	Pulse dose
Flow settings	1	3	5
Max oxygen output	330 ml/min	500 ml/min	1,000 ml/min
Noise level	41 dBA	38-44 dBA (depends on setting)	48 dBA
FAA-approved	Yes	Yes	Yes
Bluetooth capabilities	No	No	No

Understanding AirSep portable oxygen concentrator models

AirSep Focus: Most Lightweight

The AirSep Focus is among the lightest portable oxygen concentrators on the market. It weighs 2 pounds and is shorter than a plastic water bottle. The next lightest we’ve researched is the Inogen Rove 4 at 3 pounds.

AirSep Focus

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One of the smallest available portable oxygen concentrators
Comes with a carry bag and batteries

Lightweight

Weight: 2 lbs (with microbatteries)
Dimensions: 4.8 inches x 2.5 inches x 6.4 inches
Battery life: 3 hours
Battery charging time: 4 hours
Delivery/flow type: Pulse dose
Range of flow settings: 1
Noise level: 41 dBA

The AirSep Focus comes with the following supplies:

Focus concentrator unit
Two rechargeable micro batteries
Universal AC power supply/charger
Carrying bag
Shoulder strap
Nasal cannula
User manual/documentation

You can purchase extra accessories for your Focus. These accessories include a DC car charger and an AirBelt. The AirBelt is a battery belt worn around the waist, like a fanny pack, that provides up to four extra hours of use.

Pros

Discreet
FAA-approved
Three-year warranty

Cons

3-hour battery life
No Bluetooth capability
Lower oxygen output

What’s different about the AirSep Focus

Each of this model's microbatteries works for 1.5 hours, giving you a total of 3 hours of use between charges. This makes the Focus great for quick trips to the store, a long walk, and chores or hobbies around the house. Because it’s FAA-approved, you can also take the Focus on a plane. But the portability comes with a shorter battery life. With only three hours of battery life, you may need to charge it in the car on the way to the airport and use a wall outlet while at your gate and on the plane. You can charge your AirSep Focus while it’s in use.

At 41 dBA (A-weighted decibels), the AirSep Focus is well within what the Hearing Health Foundation considers "average room noise." Other portable oxygen concentrators have a more noticeable hum. With all accessories attached, the AirSep Focus weighs 3.5 pounds. That weight is lighter than most portable oxygen concentrators. Many of our survey respondents reported being "embarrassed" by their portable oxygen.1 A concentrator this size might be discreet enough to address those concerns.

Home oxygen concentrators fall somewhere between carry-on suitcases and mini fridges in size. Portable oxygen concentrators use the same technology and concepts as those devices, but shrink them to take on the go. The primary difference, aside from size, is continuous flow versus pulse dosing. Home oxygen therapy can provide oxygen in a continuous stream through your nasal cannula. Most portable oxygen concentrators rely almost wholly on “pulse dose” delivery instead. Pulse dose oxygen comes in bursts, not a steady stream. Many portable oxygen concentrators on the market have multiple pulse settings, but the AirSep Focus has only one. It’s common for portable oxygen concentrators to have four to six settings.

Simply put: Being small means less oxygen. The AirSep Focus’s max output is 330 mL/min. The next-smallest portable concentrator on the market, the Inogen Rove 4, has an output of 840 mL/min—more than double the AirSep Focus's rate. Many standard-size portable oxygen concentrators generate up to 1,500 mL/min. This means the AirSep Focus delivers oxygen at 22% of the rate of other portable oxygen concentrators—some of which cost about the same. You’ll have to decide whether the AirSep Focus's compact size is worth the lower oxygen output at the same price.

AirSep FreeStyle 3: Best for Summer and Warm Climates

The AirSep FreeStyle 3 can deliver almost 200 mL/min more oxygen than the Focus while still weighing less than 10 pounds. It suits a wider variety of supplemental oxygen users. The FreeStyle 3 is also built to function in temperatures up to 104 degrees. This temperature range is rare among the portable oxygen concentrators we reviewed.

AirSep FreeStyle 3

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Longer battery life than the AirSep Focus
“One-touch” operation

Matte finish can help hide dings and scrapes

Weight: 5 lbs
Dimensions: 6.1 inches x 3.6 inches x 8.6 inches
Battery life: 3.5 hours
Battery charging time: 4–5 hours
Delivery/flow type: Pulse dose
Range of flow settings: 3
Noise level: 38–44 dBA

The FreeStyle 3 comes with the following supplies:

FreeStyle 3 concentrator unit
Nasal cannula
Universal AC power supply/charger
AC power cord
DC car adapter/power cord
Internal rechargeable battery
Adjustable shoulder strap
Carry bag
User manual/documentation

You can purchase extra accessories for your FreeStyle 3, such as the wrist-strap carry bag or the FreeStyle backpack.

Pros

Built to handle high temperatures
Starts up in 2 minutes
Three pulse settings

Cons

Delivers less oxygen than other portable concentrators
Some carry options cost extra
Doesn’t arrive fully charged
No AirBelt compatibility

What’s different about the AirSep FreeStyle 3

While the 3-pound Focus is the size of a canteen, the FreeStyle 3 resembles a hard-sided lunchbox. It also weighs about 3 pounds more than the Focus. But that extra weight is due to a bigger oxygen delivery system. The FreeStyle 3 can deliver up to 500 mL/min due to two more pulse-dose settings than the Focus.

The extra settings on the FreeStyle 3 may be helpful for people who have a higher oxygen prescription. The FreeStyle can meet a higher (or fluctuating) oxygen demand. The Focus, with its single pulse-dose setting, could not. The FreeStyle 3 also includes AirSep’s UltraSense technology, which helps the oxygen match your breathing rate.

The FreeStyle 3 warms up in two minutes after the touch of a single button. If you’re plugged into AC power (like a wall outlet), your FreeStyle 3 will charge whether you’re using the machine or not. This may be useful for anyone flying with their FreeStyle 3. It means you can charge your portable oxygen concentrator on the plane and at your gate.

Another helpful feature of the FreeStyle is the Breath Rate Exceeded alarm. While the FreeStyle has more pulse dose settings than the Focus, they might not be enough if you overexert yourself. If your required oxygen intake exceeds what the machine can produce, an alarm will sound. When the alarm sounds, reduce your physical activity and switch to another oxygen source if available.

I wouldn’t be afraid to fluctuate oxygen. You may have one prescription at rest, one prescription at exertion.”

—Alexis Smith, DO, at Novant Health, pulmonary and critical care medicine

AirSep FreeStyle 5: Highest Output

The FreeStyle 5 is the largest of the three models in this AirSep portable oxygen concentrator review. It also offers the most pulse-dose settings, with five. This means the FreeStyle 5 can deliver up to 1,000 mL/min of oxygen.

AirSep FreeStyle 5

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Includes UltraSense auto-adjusting technology
2.5 hours of battery life

FAA-approved

Weight: 6.7 pounds
Dimensions: 6.6 in x 4.4 in x 10.7 in
Battery life: 2.5 hours
Battery charging time: 4–5 hours
Delivery/flow type: Pulse dose
Range of flow settings: 5
Noise level: 48 dBA

The FreeStyle 5 comes with the following supplies:

FreeStyle 5 concentrator unit
Internal rechargeable battery
Universal AC power supply/charger
AC power cord
DC car adapter/power cord
Carrying case or carry bag
Adjustable shoulder strap
Nasal cannula
User manual/documentation

You can purchase extra accessories for your FreeStyle 5, such as the AirBelt battery or a different carry bag.

Pros

Compatible with AirBelt
High oxygen output
Whisper-quiet

Cons

2.5-hour battery life
Long charging time
Battery is not removable

What’s different about the AirSep FreeStyle 5

The AirSep FreeStyle 5 stands out for its oxygen production. The FreeStyle 5 can deliver up to 1,000 mL/min of oxygen. That’s more than triple the amount of oxygen the AirSep Focus can deliver. The five pulse-dose settings that give the FreeStyle 5 its name enable the delivery of extra oxygen at varying concentrations. That extra power does mean a little more noise, as the FreeStyle 5 runs at 48 dBA while the FreeStyle 3 runs at 38 dBA. But AirSep reports the FreeStyle 5 is “equivalent to the noise level in a library.”

While bigger, the FreeStyle 5 has less battery life (2.5 hours) than the FreeStyle 3 (3.5 hours). Its increased oxygen output drains the battery faster. The FreeStyle 5 is the only machine in this review that features AirSep’s UltraSense technology. UltraSense automatically adjusts the oxygen bolus based on your breathing rate. This way, you won't take in more oxygen than you need.

Like the Focus, the FreeStyle 5 is compatible with the AirBelt, AirSep’s fanny pack-like battery belt. Some portable oxygen concentrators have batteries you can swap out for fully charged ones, similar to an electric mower or drill. But the AirSep FreeStyle 5 battery cannot be removed. Your only option once you run out of charge is to use the machine during its 4–5-hour charging period. This means you’re tethered to the outlet as your FreeStyle 5 charges, unless you’ve paid extra for the AirBelt mobile battery belt. The AirBelt can offer up to four extra hours of charge.

How much do AirSep portable oxygen concentrators cost?

The cost of oxygen concentrators was by far the biggest concern of our survey respondents—and with good reason.¹ Oxygen concentrators are expensive.

AirSep’s online store focuses on business- and building-sized oxygen solutions. It doesn't sell AirSep portable oxygen concentrators directly. Those are only available through third-party sellers, such as the Oxygen Concentrator store. These retailers list the whole AirSep portable oxygen concentrator family with a starting price of $2,695.

That’s about average for a portable oxygen concentrator. CAIRE portable oxygen concentrators fall within the $2,000–$3,000 range. Competitors Inogen and Invacare also fall within this price range. Portable oxygen concentrators that deliver higher oxygen flow rates (1,500–2,500 mL/min) can cost as much as $4,000.

Comparison Features	AirSep Focus Visit Sitefor AirSep Focus	AirSep FreeStyle 3 Visit Sitefor AirSep FreeStyle 3	AirSep FreeStyle 5 Visit Sitefor AirSep FreeStyle 5
Estimated cost	$2,695	$2,695	$2,695
Warranty or protection plan	3 years on machine, 1 year on batteries and accessories	3 years on machine, 1 year on batteries and accessories	3 years on machine, 1 year on batteries and accessories
Free trial	No	No	No

Who should use AirSep

Since they’re so lightweight, AirSep portable oxygen concentrators may be a good fit for people who value discretion. They may also be a good option for those who can’t or don’t want to carry a bulky machine around. Frequent flyers might appreciate that all AirSep’s portable oxygen concentrators are FAA-approved.

Who should not use AirSep

Folks who enjoy being mobile for long stretches of time. The battery life in the AirSep lineup is comparatively short. If you're mobile for more than three hours, you’ll need to charge your device. You can pay extra for the AirBelt or ensure you’re near an outlet that can charge your AirSep as you use it.

People with high oxygen prescriptions. Certain oxygen prescription levels won’t be met by a portable oxygen concentrator. Your prescribed dose may require continuous-flow oxygen or a device that delivers higher pulse doses than the AirSep family can.

“There are some people that need a certain number when they are just sitting down, but as they exert themselves walking or straining or carrying something, they may need a little bit more during a specific activity,” said Alexis Smith, DO, at Novant Health, pulmonary and critical care. “I wouldn’t be afraid to fluctuate oxygen. You may have one prescription at rest, one prescription at exertion.”

To ensure your pulse dose oxygen is working properly, measure your blood oxygen levels with a pulse oximeter. You can read our Oxiline pulse oximeter review to learn more about these devices and how we review them.

AirSep customer reviews

AirSep, a division of CAIRE, is not accredited by the Better Business Bureau (BBB), and neither is CAIRE, so it does not have a customer rating on the site. The BBB has given AirSep an A+ rating. BBB ratings include factors such as how promptly the company responds to complaints.

AirSep is not verified on Trustpilot, but Oxygen Concentrator Store—which sells AirSep to the public—is. Oxygen Concentrator Store has a 4.8 out of 5 Trustpilot rating. Below are some AirSep oxygen concentrator reviews from the Oxygen Concentrator Store.

“Unit lasts me exactly 2 hours and then begins emitting a loud alarm. Definitely not getting 2.5”

—Ann, reviewing the AirSep FreeStyle 5 (OXYGENCONCENTRATORSTORE)

“I'm happy with my Focus because it's small and quiet. I work in a call center, and it doesn't bother anyone at all. I have the freedom of getting my oxygen therapy at work, as well as out and about.”

—Shelly, reviewing the AirSep Focus (OXYGENCONCENTRATORSTORE)

“I take my Focus with me everywhere. Very easy to wear a loose jacket and cover it, but without keeping the oxygen from getting to it. I went skiing while using it!”

—Will, reviewing the AirSep Focus (OXYGENCONCENTRATORSTORE)

Frequently asked questions

Is the AirSep portable oxygen concentrator pulse dose or continuous flow?

AirSep portable oxygen concentrators deliver pulse-dose oxygen. The AirSep FreeStyle 5 has five pulse dose settings. The AirSep Focus has a single setting.

What oxygen settings does the AirSep portable oxygen concentrator offer?

That depends on which machine you have. The AirSep Focus has a single pulse-dose setting. The FreeStyle 3 has three pulse-dose settings, and the FreeStyle 5 has five settings.

How much does the AirSep portable oxygen concentrator weigh?

AirSep’s line of portable oxygen concentrators weighs 2–6.7 pounds. The AirSep Focus is the lightest in the lineup, weighing 2 pounds with its batteries installed.

Is the AirSep portable oxygen concentrator FAA-approved?

Yes. All portable oxygen concentrators in the AirSep lineup are FAA-approved.

Can I use an AirSep portable oxygen concentrator while sleeping?

If you have no other option (like during travel), you can use a portable oxygen concentrator while sleeping. Nighttime oxygen is usually delivered via stationary oxygen concentrators. That’s because you regulate breathing differently while sleeping (at night, your body doesn’t send the same breathing signals as during the day). Your doctor may base your nighttime oxygen prescription on your waking prescription. This may be a higher flow rate than a portable concentrator can deliver.

Questions? Email us at reviewsteam@ncoa.org.

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AirSep Portable Oxygen Concentrator Review

In This Review

Comparing AirSep portable oxygen concentrators

Understanding AirSep portable oxygen concentrator models

AirSep Focus: Most Lightweight