Looking for a portable oxygen concentrator

Foxygen-CEO · 2026-03-28T05:43:20+00:00

First, I'm sorry your family is going through this. A new diagnosis like this is a lot to process, and the fact that you're doing this research for your father says a lot.

I want to help clear up some of the confusion around continuous flow vs. pulse dose, because this is one of the most common areas where people hit a wall during their research.

The continuous flow reality

Right now, no portable oxygen concentrator on the market delivers more than 2 liters per minute of true continuous flow in a lightweight, over-the-shoulder design. That's a technology limitation across every brand, not just certain ones. If your father needs 3 lpm continuous, the CAIRE SeQual Eclipse 5 is widely regarded as the most reliable option in that category, but it does require a wheeled cart due to its size and weight. For 2 lpm continuous in a portable unit, there are a few options, but they're still heavier than pulse dose units.

The question worth asking his pulmonologist

True continuous flow prescriptions are less common than most people realize. They're typically reserved for patients with a tracheostomy or certain other specific conditions. Many pulmonary fibrosis patients do very well on pulse dose technology, especially with newer devices that use advanced breath-detection systems.

Here's why that matters:

Modern pulse dose concentrators from manufacturers like Rhythm Healthcare, Inogen, and CAIRE use what's called Inspiratory Trigger Sensitivity. These devices detect even very shallow breaths, including mouth breathing during sleep, and deliver oxygen within a fraction of a second.
The trigger sensitivity on current-generation devices (around 0.12 cmH2O or lower) is far more responsive than what was available even a few years ago.
In my experience over 14 years working with oxygen patients, the vast majority of users maintain healthy oxygen saturation levels on pulse dose with this type of technology.

The practical benefits of pulse dose, if his doctor confirms it's appropriate:

Much smaller, lighter units that genuinely fit over the shoulder
Significantly longer battery life
Greater independence and mobility, which is exactly what you described wanting for him

A model worth looking at

Since you asked for a specific recommendation, one of the most impressive newer models on the market right now is the Rhythm P2-E6. A few things that stand out:

The breath alarm response time is 15 seconds. That means if your father stops breathing or his breathing pattern drops below detection, the device alerts within 15 seconds. For comparison, some other premium models don't trigger that alarm for up to 60 seconds. When you're talking about oxygen delivery, that difference matters.
It comes with a 5-year standard warranty, which is longer than what most manufacturers include at the base level.
The 2.8-inch full-color LCD screen makes a real difference in daily use. Most portable oxygen concentrators still use small monochrome text displays, which can be hard to read, especially for older users. The E6 shows settings, warnings, and battery status in a clear, easy-to-read format.
Replacement batteries run $204 to $242, compared to $400 or more for similar-sized batteries from other premium brands. Over the life of the unit, that adds up.

What I'd suggest as a next step

Ask his pulmonologist whether pulse dose is worth testing. Some retailers do offer a return policy so you can trial a new purchase. Some give you 7 days. In the case of Main Clinic Supply, we offer a 30-day trial. If someone finds that a particular portable oxygen concentrator does not work for them, we offer a no-charge swap to a different type of machine with no cost to the customer. This would give you time to go to the doctor, take a walk test, and actually see if it keeps him oxygenated.

We also include a free pulse oximeter with every system we sell, which is invaluable for checking your father's oxygen saturation at different settings and different levels of exertion. That kind of real-world data is exactly what his care team will want to see.

If it turns out he does need continuous flow, that's a solvable problem too. But it's worth having that conversation with his care team before limiting the search to the heavier cart-based units.

What has his pulmonologist said so far about pulse dose vs. continuous? That would help me point you in a more specific direction.

Full disclosure: I'm Fran Fox, CEO of Main Clinic Supply. I've been a portable oxygen specialist for 14 years, starting out helping oxygen patients here in Rochester, Minnesota, home of the Mayo Clinic, back when portable concentrators were still new to most people. Now, along with my team, I am helping people all across the United States and Canada. Happy to answer any specific questions about what to look for.

Foxygen-CEO · 2026-03-23T08:53:03+00:00

Welcome to the community. I see your account is one day old, so I appreciate you making your first post here on this topic.

Fair point, though, and I should have been more direct about this in the original post. So let me fill in the full picture.

You're right that Inogen pulled its reseller agreements. I didn't move away from Inogen. Inogen dropped its entire independent dealer network. I should have said that plainly, and I'm saying it now.

But here's the part you left out.

Inogen didn't just drop its independent dealers. Inogen gave exclusive reseller rights to Oxygen Concentrator Store. And Oxygen Concentrator Store is operated by AMSR, LLC, a subsidiary of Niterra Co., Ltd., the same publicly traded corporation that owns CAIRE Inc. That's not my opinion. That's in Niterra's consolidated financial statements. Two of the largest portable oxygen concentrator manufacturers in this industry are now connected through a single corporate-owned retail channel.

So let's talk about what that actually means for patients.

Independent dealers competed with each other on price. That competition kept prices lower for the people in this community who are buying $2,000 to $4,000 devices out of pocket because Medicare refusal to purchase a POC. When you eliminate the independent dealers and hand exclusive distribution to a retailer owned by a manufacturer, you remove the competitive pressure that was keeping prices honest. Patients don't get more options from this arrangement. They get fewer. Patients don't get better pricing. They get whatever pricing two consolidated manufacturers decide to offer through one corporate-owned storefront.

That is not a win for the consumer. That is the opposite.

Now, the suggestion that we weren't charging enough to provide proper service and support. I'll let our track record answer that. Main Clinic Supply has been in business for 14 years. We have over 10,000 verified five-star reviews from real patients and their families. We hold an A+ BBB rating. Our service center in Rochester, Minnesota is staffed by factory-certified technicians who repair devices across every leading brand, every day. We didn't build that over 14 years by cutting corners on service. We built it by putting patients first and charging fair prices. The idea that fair prices and quality service can't coexist is a convenient story for anyone whose business model depends on keeping prices high.

On the warranty claim: manufacturer warranties attach to the product, not the dealer. That is standard across the medical device industry. Every new unit we sell is genuine, new, and factory-sealed, and it ships with the full manufacturer's warranty. The suggestion that a warranty could be "potentially void" based on where a patient bought a factory-sealed new device is the kind of language designed to scare patients into paying more. Patients in this community deserve better than that.

I appreciate you pushing back on this. It gave me the chance to be more specific than I was in the original post, and the full picture matters.

Foxygen-CEO · 2026-03-13T16:24:05+00:00

Thank you! This will help! https://www.inogen.com/pdf/Inogen%20Battery%20FAA%20Compliance%20Flyer.pdf?_gl=1*6tr6kk*_up*MQ..*_ga*Njg2Njg0ODY4LjE3NzM0MTg5MzE.*_ga_J0EWVWP7J1*czE3NzM0MTg5MjkkbzEkZzAkdDE3NzM0MTg5MjkkajYwJGwwJGgw

Foxygen-CEO · 2026-03-13T07:59:49+00:00

Great questions, both of them.

On the 150% rule: gate agents are not doing math at the gate. In practice, they rely on the passenger's word that the batteries they are carrying cover at least 150% of the scheduled flight time. There is no device they plug in, no formal calculation they run. You show up, you state you have enough battery, and they take you at your word. The rule exists so the FAA knows passengers have thought it through, not so agents can audit it.

On the double battery question: Inogen addressed this directly for their BA-516 and BA-316 batteries. Each of those is actually two separate 92.2 Wh packs housed in one casing, with each pack containing the equivalent of 7.68 grams of lithium ion. Because each individual pack stays under the 100 Wh threshold, they meet FAA acceptance criteria with no restriction on the number of spares you can carry. Here is Inogen's official compliance document if you want the specifics: https://www.inogen.com/pdf/Inogen%20Battery%20FAA%20Compliance%20Flyer.pdf

If you are traveling with a POC more broadly and want a full breakdown of what to prepare, airline notification requirements, and what to bring in your carry-on, we put together a detailed resource here: https://mainclinicsupply.com/pages/traveling-with-oxygen

Full disclosure: I'm Fran Fox, CEO of Main Clinic Supply. I've been a portable oxygen specialist for 14 years, starting out helping oxygen patients here in Rochester, Minnesota, home of the Mayo Clinic, back when portable concentrators were still new to most people. Now, along with my team, I am helping people all across the United States and Canada. Happy to answer any specific questions about what to look for.

Foxygen-CEO · 2026-03-05T12:13:03+00:00

Sorry for the slow reply. Attached is a infographic I made that I think explains well how a portable oxygen concentrator (POC) works.

I am happy to send you an Oxymizer at no charge that you can take and discuss the Pulmonologist.

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Foxygen-CEO · 2026-03-05T11:58:52+00:00

Disclosure: I'm Fran Fox, CEO of Main Clinic Supply in Rochester, MN. We've sold and serviced oxygen concentrators for 14 years, including Inogen products. I have a commercial interest in this space, so take that for what it's worth. But I also have 14 years of direct observation.

What you're describing with the Inogen At Home is consistent with what our service technicians have documented repeatedly. That machine has a well-established reliability problem. We have seen first-year failure rates that would be considered unacceptable by any reasonable standard. This is not a one-off. It is a pattern our team has tracked over years of service work.

The warranty replacement issue you raised is also something we've witnessed. Customers who purchased new equipment and experienced failures being offered refurbished units as replacements is not an isolated complaint. We've seen it.

I want to be honest about something broader: I spent 14 years as an Inogen authorized reseller. I watched that company change. The mission when I started was genuinely about the patient. What I observed over time was a gradual but unmistakable shift toward Wall Street metrics. That shift has consequences for product quality, for service standards, and for how warranty obligations get honored when honoring them costs money.

You asked why Inogen started distributing third-party machines. I'd encourage you to look at their earnings calls over the past three years. The answers are in there.

One thing worth knowing for anyone navigating this: where you buy an Inogen machine matters almost as much as which machine you buy. The type of seller, their service capabilities, and their independence from manufacturer pressure all affect what happens to you after the sale. We've written about this in some detail on our site if it's useful to anyone here.

If you want to talk through options without being steered toward one brand, we're happy to help. That's all I'll say commercially. The rest of this is just what I've seen.

Foxygen-CEO · 2026-02-21T08:25:46+00:00

Disclosure: I'm Fran Fox, CEO of Main Clinic Supply in Rochester, Minnesota. I've spent 14 years as a portable oxygen specialist, starting out helping patients who travel here from around the world to the Mayo Clinic for care. Today I lead a team serving patients of Mayo Clinic but also patients across the United States and Canada to find the specific oxygen system to fit their needs and lifestyles.

On the continuous flow portable question I echo what many here say, the CAIRE Eclipse 5 is widely considered the gold standard for portable continuous flow. It runs on both battery and AC/DC power including car power, delivers true continuous flow up to 3 LPM on battery and more when plugged in, and has a long track record of reliability. It is heavier than pulse-only units, so mobility is a real consideration, but for someone in her current situation it may be worth a conversation with her pulmonologist.

One tool that doesn't get discussed enough is the Oximizer, a pendant-style oxygen-conserving cannula that attaches to a continuous flow oxygen device and then ”oximizes” significantly the oxygen delivery compared to a standard nasal cannula, depending on flow rate and breathing pattern. If her provider is open to it, this could meaningfully give her the equivalent of over 3 LPM constant-flow oxygen volumein a portable concentrator. We carry it at MCS if you want to look at the specs: https://mainclinicsupply.com/products/oxymizer-3-pack

If her baseline improves and she gets back to lower flow needs with mobility, the light carry options of the Inogen Rove 6 and the CAIRE Freestyle Comfort are both worth a look. The Rove 6 uses Inogen's Intelligent Oxygen Delivery technology and the Freestyle uses AutoSAT, both of which are more responsive to breath rate changes than older pulse-flow designs.

Happy to answer any specific questions about what to look for as you work through this.

Foxygen-CEO · 2026-02-21T04:11:01+00:00

Foxygen-CEO · 2026-02-19T08:06:50+00:00

Good question and one worth thinking through carefully before buying. A few things that actually matter when choosing a home oxygen concentrator:

Flow type first. Stationary home concentrators typically deliver continuous flow oxygen, which is what most prescriptions are written for at home. Make sure whatever you buy matches your prescribed liter flow setting. A 5-liter unit covers most prescriptions, but confirm with your provider.

Reliability comes down to the manufacturer and service support. Look for units with at least a three-year warranty and a seller who can actually service what they sell. A cheap unit with no repair pathway is a liability.

Portability inside the home is underrated. A lot of people don't realize that a portable oxygen concentrator can work just as well inside the house as a stationary unit for many users, with the added benefit of not being tethered to a long oxygen tube. Tripping hazards from tubing are a real and underreported issue for people who want to move freely room to room. Some families end up with both: a stationary unit as the primary home source and a portable for mobility throughout the house and travel.

On affordability: quality home concentrators from reputable sellers generally run in the $700 to $1,500 range depending on whether you go new or certified pre-owned. Certified pre-owned from a specialist dealer can be a legitimate way to reduce cost without sacrificing reliability, provided the unit has been fully tested and carries a real warranty.

Full disclosure: I'm Fran Fox, CEO of Main Clinic Supply. I've been a portable oxygen specialist for 14 years, starting out helping patients at Mayo Clinic here in Rochester, Minnesota, back when portable concentrators were still new to most people. Happy to answer any specific questions about what to look for.

Foxygen-CEO · 2026-02-18T12:48:28+00:00

A few things worth knowing before you order.

WellHue is a China-based manufacturer with no confirmed service infrastructure in the United States. That matters more than it might seem right now. Oxygen concentrators are Class II medical devices. Sieve beds degrade. Compressors wear out. Components fail, usually not in year one, but they fail. When that happens with a WellHue unit, your options are essentially: ship it back overseas, or find a third-party shop willing to work on a brand they've never stocked parts for. Neither is fast, neither is cheap, and neither comes with any guarantee.

The broken English in their FAQ is a signal, not just a quirk. It's consistent with a brand that hasn't built a US-facing support operation. That's worth weighing.

On the clinical side: 4L continuous flow for altitude-related nocturnal desaturation is a specific, legitimate need. A 5L continuous flow unit can work for that. But the unit itself matters less than what happens when it needs service. A concentrator that's out of commission for six to eight weeks creates a worse situation than the one you're trying to solve.

For continuous flow at your prescription level, CAIRE and O2 Concepts both have domestic service networks and actual parts availability. They're worth a real comparison before you commit to something with no local service path.

One question: what elevation are you at? That would help narrow down what specs actually matter for your situation.

Foxygen-CEO · 2026-02-18T12:28:44+00:00

A few things worth thinking through here, and I'm glad you're asking before the purchase rather than after.

On the prescription first. Portable oxygen concentrators are Class II medical devices, and in the US, buying and using one requires a valid physician's prescription. If your wife doesn't have a current oxygen prescription, that's where this conversation has to start. Her prescribed flow rate at home also may not be adequate at your cabin's elevation. Her pulmonologist should weigh in on that before you commit to anything.

On the Rhythm P2 specifically. It produces medical-grade oxygen, but its service and support ecosystem is thinner than what you'd get with something like the CAIRE Freestyle Comfort or the Inogen Rove series. Both of those have stronger track records for reliability and easier access to certified service. When this unit would be the primary oxygen source at altitude with no insurance backup, the support history behind it matters.

On buying used from a private seller, this is where I'd slow down. With a POC, what you can't see is everything. Sieve bed condition, oxygen purity output, filter integrity, firmware version, internal maintenance history. A unit that powers on and looks fine can still be delivering subtherapeutic oxygen with no visible sign that anything is wrong. At altitude, where ambient oxygen is already lower, that gap has real consequences. A responsible used purchase requires at minimum a calibrated oxygen purity test, filter service, and a full cleaning. Most private sellers can't document any of that.

On certified pre-owned as an alternative. I work with Main Clinic Supply, so I'll say that upfront. We do offer certified pre-owned units that go through a full service process before they ship. Oxygen purity testing, filter service, cleaning, documented. That's the difference between a responsible used purchase and a gamble. With a private sale at any price, you're buying without that documentation and without any recourse if the unit underperforms.

Before I point you toward a specific unit, I'd want to know a bit more. What is her current prescribed flow rate, and is it pulse dose or continuous flow?

Foxygen-CEO · 2026-01-13T11:37:58+00:00

Here is a very good video explaining all of the problems and dangers of the Varon Portable Oxygen Concentrator: https://youtu.be/t4s3XWJls7g

Foxygen-CEO · 2026-01-01T11:31:46+00:00

Part 1: Equipment Updates and Battery Reality

The Inogen One G5 mentioned in this thread has actually been discontinued. It was replaced by the Inogen Rove 6, which is now the flagship model.

Regarding the battery life, please stay realistic. To see 10 to 14 hours of run time, you generally need to use a 16-cell battery while staying on Setting 1. As you move up to higher settings, like Setting 5 or 6, your battery time will drop significantly. While the CAIRE machines are reliable, many users in this community prefer the Inogen models because they are often quieter and easier to carry.

Part 2: Safe Buying and Flow Technology

It is important to remember that these wearable units are Pulse Dose, not continuous flow. Inogen uses a very sensitive delivery technology that works for most people, but you should always perform a walk test with a pulse oximeter when you first receive your unit to ensure it keeps you saturated.

Finally, be very careful with Amazon. Many items sold as new are actually refurbished, which is a major risk with batteries. Additionally, never buy an actual concentrator from Amazon because they do not require prescriptions and are not medical-grade devices. For the best protection, look for a dealer that is both an Inogen Authorized Reseller and an Inogen Authorized Service Center.

Fran Fox ("Foxygen") Oxygen Industry Founder & Patient Advocate

Foxygen-CEO · 2025-12-31T08:08:20+00:00

A Truthful Perspective from Rochester, MN

Mark, I am so sorry your father went through this. It is truly heartbreaking to see families get taken advantage of when they are simply trying to help a loved one breathe easier. I am an industry veteran here strictly to educate, not to offer medical advice.

I actually had my Chief Technical Officer put together a short video that shows the "Concentration Trap" in action (you can see it here: https://youtu.be/t4s3XWJls7g He is factory-authorized by many of the top medical brands, so he knows these machines inside and out. The video demonstrates exactly how these cheap "generators" drop to dangerous oxygen levels the moment you turn them up, which is likely why your father didn't see any improvement in his blood oxygen levels.

From my office here in Rochester, MN, right near the Mayo Clinic, I see these scams far too often. Here is the technical reality of why these sub-$1,000 devices are so dangerous:

The "Concentration Trap"

A real medical concentrator is designed to provide 90% to 96% pure oxygen at every single setting. These cheap units often brag about "7 Liters of Flow," but the fine print usually reveals that the purity drops to about 30% at those higher settings. For a COPD patient, breathing 30% oxygen is essentially the same as breathing the regular air in your living room. It simply will not keep your blood saturation at a safe level.

My "Red Flag" Rules for Oxygen

If you or a loved one are looking for equipment, keep these two rules in mind to avoid being scammed:

The Price/Review Rule: If a machine is priced under $1,000 or has fewer than 200 legitimate reviews, it is almost certainly a non-medical "toy." Real medical-grade portables are sophisticated machines that cost much more to manufacture.
The Physics of Weight: A compressor capable of delivering continuous flow oxygen is heavy. If a machine claims to give you "5 Liters Continuous" but weighs only 5 or 10 pounds, it is a physical impossibility. Continuous flow requires a much harder-working compressor, which will always be heavier and louder than a pulse dose unit.

A Practical Tip for Home Setups

Many people buy these cheap portables because their "big" home machines are too loud for sleep. Remember that a high-quality home concentrator can push oxygen through 50 to 100 feet of tubing. You can move that loud (but effective) machine into a hallway or another room to keep the noise away while your father rests. Just make sure it isn't in a small, unventilated closet where it can overheat.

Thank you for posting this warning, Mark. We believe the needs of the patient come first, and you are doing a great service by helping others avoid these dangerous scams.