An oxygen therapy machine concentrates ambient air to deliver medical-grade oxygen, and choosing the right one depends on your flow rate needs, portability requirements, and budget. Whether you need a stationary home concentrator for continuous overnight use or a portable unit for travel, understanding the technology behind these devices helps you make a better decision. This guide covers how oxygen concentrators work, the different types available, key specs to compare, price ranges, prescription requirements, and insurance coverage.
Key Takeaways
- Oxygen concentrators use pressure swing adsorption (PSA) to extract oxygen from room air, delivering 90% to 95% pure oxygen.
- Stationary concentrators deliver 5 to 10 L/min continuous flow and cost to ,500.
- Portable concentrators weigh 3 to 10 lbs, deliver pulse-dose or up to 3 L/min continuous, and cost to ,000.
- All medical oxygen concentrators require a prescription in the United States.
- Medicare Part B covers oxygen equipment rental for qualifying patients.
How Oxygen Concentrators Work
Oxygen concentrators do not store oxygen. Instead, they extract it from the air you are already breathing. Room air is approximately 78% nitrogen and 21% oxygen. The concentrator removes the nitrogen and delivers concentrated oxygen.
The core technology is called pressure swing adsorption (PSA). Here is how it works:
Step 1: Air intake. A compressor draws ambient air into the machine through an intake filter that removes dust and particles.
Step 2: Compression. The air is compressed and directed into one of two cylinders (called sieve beds) filled with zeolite, a naturally occurring mineral with a crystalline structure full of microscopic pores.
Step 3: Nitrogen adsorption. Under pressure, nitrogen molecules bind to the zeolite surface. Oxygen molecules, being smaller, pass through. The result is a gas that is 90% to 95% pure oxygen.1
Step 4: Purge cycle. While one sieve bed is adsorbing nitrogen, the other releases (purges) its accumulated nitrogen back into the room. The two beds alternate in cycles, providing continuous oxygen output.
This is why concentrators are sometimes called “oxygen generators.” They generate concentrated oxygen from air on demand, as long as they have power.
Types of Oxygen Therapy Machines
Stationary (Home) Concentrators
Stationary concentrators are designed for home use. They plug into a standard wall outlet and deliver continuous-flow oxygen at higher rates than portable units.
Best for: Patients who need oxygen primarily at home, especially those requiring higher flow rates (5 to 10 L/min). Commonly used for COPD, pulmonary fibrosis, and sleep-related oxygen needs.
Typical specs:
- Flow rate: 5 to 10 L/min continuous
- Oxygen purity: 90% to 95%
- Weight: 30 to 55 lbs
- Noise level: 40 to 55 dB (comparable to a refrigerator)
- Power: 300 to 600 watts
- Price: to ,500
Popular models include the Invacare Platinum 10, Philips Respironics EverFlo, and DeVilbiss 525DS.
Portable Oxygen Concentrators (POCs)
Portable concentrators run on rechargeable batteries and are designed for mobility. They are FAA-approved for air travel and allow patients to maintain oxygen therapy outside the home.
Best for: Active patients who need oxygen during daily activities, travel, or errands. Most POCs deliver pulse-dose oxygen (triggered by inhalation) rather than continuous flow.
Typical specs:
- Flow rate: Pulse-dose settings 1 to 6, or up to 3 L/min continuous (select models)
- Oxygen purity: 87% to 95%
- Weight: 3 to 10 lbs
- Battery life: 2 to 8 hours per charge
- Noise level: 37 to 47 dB
- Price: to ,000
Popular models include the Inogen One G5, Caire FreeStyle Comfort, and Philips Respironics SimplyGo Mini.
Transportable Concentrators
These fall between stationary and portable. They weigh 10 to 20 lbs, offer continuous flow up to 5 L/min, and can run on both AC power and battery. They are more capable than portable units but less convenient to carry.
Best for: Patients who need continuous flow but also need to move between rooms or travel by car.
Key Specifications to Compare
When shopping for an oxygen therapy machine, these are the specs that matter most:
| Specification | What It Means | What to Look For |
|---|---|---|
| Flow rate (L/min) | How much oxygen the unit delivers per minute | Match to your prescription (e.g., 2 L/min) |
| Oxygen purity (%) | Concentration of oxygen in output gas | 90% or higher for medical use |
| Continuous vs. pulse dose | Continuous delivers steady flow; pulse dose triggers on inhale | Check your prescription; some patients need continuous |
| Weight | Portability factor | Under 5 lbs for truly portable use |
| Noise level (dB) | How loud the unit operates | Under 45 dB for bedroom use |
| Battery life | Runtime on a single charge (POCs only) | 4+ hours for daily use; 8+ for travel |
Continuous Flow vs. Pulse Dose: Which Do You Need?
Continuous flow delivers a steady stream of oxygen regardless of whether you are inhaling or exhaling. This is required for patients who need oxygen during sleep (most people breathe through their mouth at night, making pulse-dose detection unreliable) or who need higher flow rates.
Pulse dose uses a sensor to detect when you inhale and delivers a burst of oxygen only during inhalation. This conserves oxygen and battery life, making the device smaller and lighter. It works well for active patients during waking hours.
Your prescription will specify which delivery mode you need. If it says “2 L/min continuous,” you need a continuous-flow machine. If it says “pulse dose setting 2,” a pulse-dose POC will work.
Oxygen Therapy Machine Price Ranges
| Machine Type | New Price | Used/Refurbished |
|---|---|---|
| Stationary concentrator (5 L/min) | to ,200 | to |
| Stationary concentrator (10 L/min) | ,200 to ,500 | to ,200 |
| Portable concentrator (pulse dose) | to ,200 | to |
| Portable concentrator (continuous) | ,000 to ,000 | to ,200 |
| Transportable concentrator | ,500 to ,000 | to ,500 |
Buying Used or Refurbished
The used market for oxygen concentrators is active. Refurbished units from reputable medical equipment suppliers can save 40% to 60% off new prices. When buying used, check:
- Hour meter: Sieve beds degrade over time. Units with under 10,000 hours typically still perform well.
- Oxygen purity test: Ask the seller to verify output purity with an oxygen analyzer. It should read 90% or higher.
- Filter condition: Ensure all filters are present and clean or new.
- Warranty: Reputable refurbishers offer 1 to 2 year warranties.
- FDA clearance: Verify the model is FDA-cleared for medical use.
Prescription Requirements
In the United States, all medical oxygen concentrators require a prescription. This applies to both purchasing and renting. The prescription must come from a licensed physician (MD, DO) or, in some states, a nurse practitioner or physician assistant.
To get a prescription, your doctor will typically:
- Perform pulse oximetry (finger clip SpO2 reading)
- Order arterial blood gas (ABG) testing if needed
- Conduct a qualifying test (resting SpO2 below 88%, or below 88% during exercise or sleep)
- Write a Certificate of Medical Necessity (CMN) for insurance purposes
Non-medical “wellness” oxygen concentrators that deliver less than 90% purity are sold without prescription, but these are not appropriate for treating medical conditions.
Medicare and Insurance Coverage
Medicare Part B covers oxygen equipment rental for qualifying patients. Here is how it works:
- Medicare rents the equipment for 36 months, then ownership transfers to the patient
- During the rental period, the supplier is responsible for maintenance and repairs
- Medicare pays 80% of the approved amount; the patient pays the 20% coinsurance
- Qualifying criteria: resting arterial PaO2 at or below 55 mmHg, or SpO2 at or below 88%
Private insurance coverage varies by plan. Most commercial plans cover oxygen therapy equipment with prior authorization and documentation of medical necessity. Call your insurance company before purchasing to understand your coverage.
“Medical-grade oxygen concentrators deliver 90% to 95% pure oxygen using pressure swing adsorption, the same technology used in hospital oxygen systems.”
World Health Organization, Technical Specifications for Oxygen Concentrators
Maintenance and Care
Proper maintenance extends the life of your oxygen concentrator and ensures consistent oxygen delivery:
Weekly:
- Clean or replace the intake filter (wash with mild soap, air dry completely)
- Wipe down the exterior with a damp cloth
- Check tubing for kinks, cracks, or moisture
Monthly:
- Inspect the nasal cannula or mask and replace if discolored or stiff
- Check the humidifier bottle (if used) and replace water
- Ensure the unit is away from walls (needs 12+ inches clearance for ventilation)
Annually:
- Professional service check (especially for stationary units)
- Sieve bed performance test
- Compressor inspection
Replace sieve beds every 15,000 to 20,000 hours of use, or when oxygen purity drops below 90%. For portable units, replace batteries when runtime drops below 50% of original capacity.
Things to Consider Before Buying
Before purchasing an oxygen therapy machine for sale, ask yourself these questions:
- What is my prescribed flow rate? This determines whether you need a stationary or portable unit.
- Do I need continuous flow or pulse dose? Check your prescription carefully.
- How mobile do I need to be? If you mostly use oxygen at home, a stationary unit is more cost-effective. If you need oxygen during errands or travel, invest in a quality POC.
- What is my altitude? Concentrators work harder at higher altitudes because the air is thinner. If you live above 5,000 feet, choose a model rated for high altitude.
- What is my power situation? For emergency backup, consider a unit with battery option or a separate portable unit.
- Will I travel by air? Only FAA-approved POCs are allowed on commercial flights. Check the airline’s approved list.
For more details on oxygen therapy equipment and accessories, see our oxygen therapy equipment guide.
Frequently Asked Questions
Can I buy an oxygen concentrator without a prescription?
Medical-grade concentrators delivering 90%+ oxygen require a prescription in the US. “Wellness” devices delivering lower concentrations can be purchased without one, but they are not suitable for treating medical conditions.
How long do oxygen concentrators last?
Quality stationary concentrators last 5 to 10 years with proper maintenance. Portable units typically last 3 to 5 years. Sieve bed replacement may be needed every 3 to 5 years depending on usage.
Are oxygen concentrators loud?
Modern units are reasonably quiet. Portable concentrators run at 37 to 47 dB (quieter than normal conversation). Stationary units run at 40 to 55 dB (comparable to a refrigerator). If noise is a concern for sleep, look for models specifically rated under 43 dB.
Can I use an oxygen concentrator while sleeping?
Yes, but you need a continuous-flow model. Pulse-dose concentrators may not reliably detect shallow breathing during sleep, especially if you breathe through your mouth. Many patients use a stationary concentrator at night and a portable unit during the day.
The Bottom Line
Choosing the right oxygen therapy machine comes down to matching your medical needs (flow rate, continuous vs. pulse dose) with your lifestyle (home use vs. portable). Stationary concentrators offer reliable, high-flow oxygen for home use at to ,500. Portable concentrators provide freedom of movement at to ,000, with tradeoffs in flow rate and battery life.
Work with your physician to determine your exact oxygen prescription, check your insurance coverage, and consider both new and refurbished options to find the best value.
- Ackley MW. Application of pressure swing adsorption for oxygen concentrators. Flexible oxygen concentrators for medical applications. Scientific Reports. 2021;11:14774. DOI: 10.1038/s41598-021-93796-3
- World Health Organization. Technical specifications for oxygen concentrators. WHO Medical Device Technical Series. Geneva: WHO; 2015. WHO Publication
- Oxygen concentrator. Wikipedia. en.wikipedia.org/wiki/Oxygen_concentrator
Medical Disclaimer
The content on BaricBoost.com is for informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
Author
Seph Fontane Pennock is the founder of BaricBoost.com and Regenerated.com, a clinic directory for regenerative medicine serving 10,000+ providers across the United States. He previously built and sold PositivePsychology.com, which grew to 19 million users and became the largest evidence-based positive psychology resource on the web. Seph brings direct experience as an HBOT patient, having completed protocols at clinics across three continents while navigating mold illness, systemic inflammation, and autoimmune conditions. His treatment journey includes hyperbaric oxygen therapy, peptide protocols, NAD+ therapy, and consultations with specialists from Dubai to Cape Town to Mexico. This combination of entrepreneurial track record and lived patient experience shapes everything published on BaricBoost.com. Every article is grounded in peer-reviewed research, informed by real clinical encounters, and written for patients making high-stakes treatment decisions. Seph's focus is on bringing transparency, scientific rigor, and practical guidance to the hyperbaric oxygen therapy space.
