If a doctor has recently mentioned “supplemental oxygen,” or you’re caring for a parent whose SpO2 keeps dipping below where it should be, you’ve probably typed some version of “oxygen concentrator” into a search bar and landed here. This guide is meant to be the one-stop explainer: what the machine actually does, who genuinely needs one, how to read the LPM and purity numbers on a spec sheet, and what separates a basic home unit from a high-flow device. By the end, you should be able to talk to your pulmonologist or a home healthcare provider with real confidence.
Table of Contents
- What Is an Oxygen Concentrator?
- How an Oxygen Concentrator Works
- Oxygen Concentrator vs Oxygen Cylinder
- Who Actually Needs an Oxygen Concentrator?
- Continuous Flow vs Pulse Dose Delivery
- Understanding LPM Ratings: 5 Liter vs 10 Liter
- Stationary (Home Use) vs Portable Concentrators
- Key Features to Check Before You Buy or Rent
- Brands Available: Philips, Oxymed, Nidek, DeVilbiss
- Buying vs Renting an Oxygen Concentrator
- Frequently Asked Questions
What Is an Oxygen Concentrator?
An oxygen concentrator is a medical device that takes ordinary room air and turns it into a steady stream of concentrated oxygen for someone who needs supplemental breathing support. Unlike a cylinder, which stores a fixed quantity of pre-compressed medical oxygen that eventually runs out and needs a refill, a concentrator manufactures oxygen continuously on the spot, for as long as it has power. That single difference is why concentrators have become the default choice for long-term home oxygen therapy in India and globally.
You’ll find these machines in ICUs, in home care setups for elderly patients, and increasingly as everyday equipment in households managing chronic respiratory conditions. If you’re exploring the category for a family member, our oxygen concentrator collection is a good place to see the range of stationary, portable, and accessory options available.
How an Oxygen Concentrator Works
The science behind an oxygen concentrator is simpler than it sounds. Room air is roughly 78% nitrogen and 21% oxygen, with small amounts of other gases mixed in. A concentrator’s job is to strip out the nitrogen and hand you back air that’s overwhelmingly oxygen.
Here’s the step-by-step process most concentrators use, called pressure swing adsorption:
- Intake: A compressor draws in ambient room air through an inlet filter that catches dust, pollen, and larger particles.
- Compression: The filtered air is compressed and pushed through sieve beds packed with a mineral called zeolite.
- Nitrogen separation: The zeolite adsorbs (traps) nitrogen molecules while letting oxygen molecules pass through, then releases the trapped nitrogen back into the room as the machine cycles.
- Delivery: What’s left is concentrated oxygen, typically in the 90-96% purity range, which is routed through tubing to a nasal cannula or mask worn by the patient.
Most home units use two sieve beds working alternately — one separates oxygen while the other purges nitrogen, which is what produces the soft rhythmic hum near a running concentrator. Because the device is simply reprocessing air already in the room, it never “runs out” the way a cylinder does; it only stops if the power does.
Oxygen Concentrator vs Oxygen Cylinder
People often ask which is “better,” but the answer depends on how long and how often oxygen is needed. Cylinders store a finite volume of compressed medical oxygen and don’t need electricity, which makes them dependable during power cuts or short trips. Concentrators need mains power (or a battery backup) but never need refilling and are far more economical for continuous, day-after-day use.
| Factor | Oxygen Concentrator | Oxygen Cylinder |
|---|---|---|
| Oxygen source | Extracted from room air, on demand | Pre-filled, compressed gas that depletes |
| Refilling | Not required — runs continuously on power | Requires periodic refilling or cylinder swaps |
| Power dependency | Needs electricity (or battery) to run | No electricity needed to deliver oxygen |
| Best suited for | Long-term, daily oxygen therapy at home | Short-term, emergency, or backup use |
| Typical purity | Around 90-96% | Can exceed 99% medical-grade oxygen |
| Fire/pressure risk | Low — no stored high-pressure gas | Higher — gas stored under high pressure |
Many households facing prolonged illness keep both: a concentrator for everyday use and a small backup cylinder for outages. If your family is weighing this decision after a recent hospital discharge, our earlier post on understanding COPD stages and when oxygen therapy is required goes deeper into the clinical side of it.
Who Actually Needs an Oxygen Concentrator?
An oxygen concentrator isn’t something to self-prescribe — it should follow a doctor’s assessment and, ideally, a pulse oximetry or blood gas reading. Conditions where long-term oxygen therapy is commonly recommended include:
- Chronic Obstructive Pulmonary Disease (COPD), particularly in its more advanced stages, when resting blood oxygen saturation stays persistently low despite inhalers and medication.
- Other chronic respiratory conditions such as pulmonary fibrosis, severe asthma complications, or interstitial lung disease.
- Post-COVID or post-pneumonia recovery where lung function takes time to return to baseline.
- Cardiopulmonary conditions like congestive heart failure with associated low oxygen levels.
- Low SpO2 readings confirmed by a physician — generally when resting oxygen saturation falls to 88% or below, or arterial oxygen pressure is persistently low, especially if complicated by pulmonary hypertension or heart strain.
Long-term oxygen therapy is typically defined as using supplemental oxygen for 15 or more hours a day, prescribed only after inhalers, medication, and lifestyle changes aren’t enough to keep oxygen levels where they need to be. The prescription will specify the flow rate (in LPM) and whether continuous or pulse delivery is appropriate — exactly what the next two sections cover.
Continuous Flow vs Pulse Dose Delivery
Once you start comparing concentrators, you’ll see two delivery styles mentioned constantly: continuous flow and pulse dose. They solve the same basic problem — getting oxygen to the patient — in different ways.
Continuous flow delivers a steady stream of oxygen at a fixed rate, measured in liters per minute (LPM), regardless of whether the person is inhaling or exhaling. It’s the standard choice for patients who need oxygen around the clock, including overnight, since it doesn’t rely on detecting a breath — useful for people whose breathing is shallow or irregular during sleep.
Pulse dose (or pulse flow) delivery uses a sensor to detect the start of an inhalation and releases a measured burst of oxygen only at that moment. Because none is wasted during exhalation, pulse dose units are markedly more efficient, which is why most portable oxygen concentrators use this method — smaller sieve beds and compressors mean a lighter, more battery-friendly device.
| Aspect | Continuous Flow | Pulse Dose |
|---|---|---|
| How it delivers oxygen | Constant stream regardless of breathing | Breath-triggered burst on inhalation only |
| Measured in | Liters per minute (LPM) | Milliliters per breath, on a numbered setting |
| Typical use case | Sleep, rest, higher/fixed oxygen needs | Daytime activity, travel, portable use |
| Device size/weight | Larger, typically stationary home units | Lighter — common in portable concentrators |
| Best for | Patients needing round-the-clock therapy | Patients who are mobile and breathe steadily |
Your physician’s prescription will usually tell you which delivery mode you need — don’t guess. If sleep-time oxygen is part of the plan, our stationary home oxygen concentrator range runs continuous flow, which is generally what’s recommended for overnight therapy.
Understanding LPM Ratings: 5 Liter vs 10 Liter
LPM stands for liters per minute — it’s the maximum rate at which a concentrator can output oxygen, and it’s the single most important spec on any device’s label. The right LPM setting for you is whatever your doctor prescribes, but it helps to understand what the common device categories are built for.
| LPM Rating | Typical Use Case | Notes |
|---|---|---|
| 1-3 LPM | Mild to moderate supplemental oxygen needs | Common starting range for early-stage prescriptions |
| 5 LPM | Moderate to standard home oxygen therapy | The most common oxygen concentrator for home use; lighter, quieter, and easier to maintain than high-flow units |
| 8-10 LPM | More severe respiratory conditions needing higher flow | An oxygen concentrator 10 liter unit is built for higher oxygen demand and is often used in clinical or advanced home-care settings |
A 5 LPM device is the workhorse of most Indian households managing COPD or similar chronic conditions — sufficient for the majority of prescriptions, more energy-efficient, and simpler to service. A 10 LPM concentrator becomes necessary when a physician has prescribed a higher flow than a 5 LPM unit can sustain, which happens with more advanced disease or step-down care after hospitalization. High-flow therapy can also dry out airway passages, so it’s often paired with a humidifier bottle. Standard 5 LPM models worth a look include the Oxymed Mini 5 LPM and Nidek Neo 5.
Stationary (Home Use) vs Portable Concentrators
Broadly, concentrators fall into two categories. Stationary units are heavier, plug into a wall outlet, and are built to run for long stretches — the standard oxygen concentrator for home use, parked in a bedroom and typically running on continuous flow. Portable oxygen concentrators are compact, battery-powered, and designed to travel with the patient, usually via pulse dose delivery to stretch battery life.
For round-the-clock therapy at home — say, overnight use for a COPD patient — a stationary unit like the Philips EverFlo 5L is usually the more practical choice. If mobility matters — travel, an active lifestyle, or oxygen needed outside the home — a portable device such as the Philips SimplyGo or DeVilbiss iGo2 is worth considering. We’ve kept the deep comparison of portable models for a dedicated post, but the full lineup is browsable under portable oxygen concentrators.
Key Features to Check Before You Buy or Rent
Not all concentrators are built equally — a few specifications matter more than brand names for day-to-day comfort and safety.
- Oxygen purity: Look for a device that consistently delivers output in the 90-96% purity range across its rated flow — this is the industry-accepted band for medical-grade concentrator output. A unit that can’t hold purity at higher flow settings isn’t doing its job properly.
- Noise level: Quieter machines generally run in the 40-60 decibel range, comparable to a quiet conversation. This matters a lot for a device that may run 15+ hours a day, often in a bedroom.
- Filter maintenance: Most concentrators have a washable external filter plus an internal filter a technician typically replaces every several months, depending on usage and dust levels. Ask about filter accessibility before committing to a unit — our oxygen concentrator accessories section stocks replacement filters and tubing.
- Alarms: A dependable concentrator should alert you audibly or visually to low oxygen purity, power interruption, low flow, or system faults — catching a problem before it becomes a health risk, especially overnight.
- LPM range and flow adjustability: Confirm the unit can be set precisely to your doctor’s prescribed flow rate, with fine adjustment rather than only broad presets.
- Continuous run duration: Home therapy units run continuously for long stretches, so check the model is rated for extended duty cycles, not just intermittent use.
Brands Available: Philips, Oxymed, Nidek, DeVilbiss
We stock oxygen concentrators from established respiratory equipment manufacturers, each with a slightly different strength:
- Philips (Respironics): A globally recognized name, known for the EverFlo stationary line and the SimplyGo portable series — solid, well-documented devices with wide service support.
- Oxymed: A budget-friendly option well suited to standard home oxygen therapy needs.
- Nidek: A Japanese brand with a reputation for reliable, low-maintenance stationary concentrators.
- DeVilbiss: Known particularly for its portable range, including the iGo2.
We’ll cover brand-by-brand specs and model comparisons in more depth in a separate post in this series.
Buying vs Renting an Oxygen Concentrator
Not every situation calls for buying outright. If you’re managing a short-term recovery — post-surgical, post-COVID, or step-down care after a hospital stay — an oxygen concentrator on rent is often the more sensible route, since it avoids committing to equipment you may only need for a matter of weeks or months. Renting also gives you flexibility to switch flow capacity if a doctor revises the prescription mid-recovery.
For ongoing, indefinite therapy tied to advanced COPD or other chronic conditions, owning a unit tends to make more sense long-term. If budget is a factor, it’s worth looking at our certified pre-owned oxygen concentrators, inspected and serviced before resale. For rentals, visit our oxygen concentrator rental page for current availability across Delhi NCR.
Frequently Asked Questions
What does an oxygen concentrator actually do?
It pulls in ordinary room air, filters out nitrogen using a process called pressure swing adsorption, and delivers the remaining concentrated oxygen — typically 90-96% pure — to the patient through a nasal cannula or mask. It runs continuously on electricity and never needs refilling.
How is an oxygen concentrator different from an oxygen cylinder?
A concentrator generates oxygen from the air around it and runs as long as it has power, while a cylinder stores a fixed volume of pre-filled compressed oxygen that eventually depletes. Concentrators suit long-term daily use; cylinders suit short-term or emergency situations since they don’t need electricity.
Who needs an oxygen concentrator?
People with chronic respiratory conditions such as COPD, pulmonary fibrosis, or other conditions causing persistently low blood oxygen (commonly SpO2 at or below 88% at rest) may be prescribed long-term oxygen therapy by a physician. It should always follow a doctor’s evaluation and prescribed flow rate, not be self-administered.
What’s the difference between continuous flow and pulse dose oxygen concentrators?
Continuous flow delivers a steady, uninterrupted stream of oxygen measured in liters per minute, suited to round-the-clock or overnight therapy. Pulse dose delivers oxygen only when it detects an inhalation, making it more efficient and common in lightweight portable concentrators.
Should I choose a 5 LPM or 10 LPM oxygen concentrator?
This depends entirely on your prescribed flow rate. A 5 LPM oxygen concentrator covers the majority of standard home oxygen therapy needs and is lighter and easier to maintain. A 10 liter oxygen concentrator is meant for higher oxygen demand, typically in more advanced respiratory conditions or clinical step-down care, as directed by a physician.
Is it better to buy or rent an oxygen concentrator?
For short-term or recovery-phase oxygen needs, renting is usually more practical and cost-effective since it avoids a large upfront commitment. For ongoing, long-term therapy tied to a chronic condition, buying — new or certified pre-owned — tends to work out better over time.
How noisy is an oxygen concentrator, and can it run overnight in a bedroom?
Good quality home concentrators typically run between roughly 40 and 60 decibels, comparable to a quiet conversation, which makes them suitable for overnight use in a bedroom. Noise level is a useful spec to compare before choosing a unit that will run many hours a day.
How often does an oxygen concentrator’s filter need to be changed?
Most units have a washable external filter that should be rinsed and dried regularly, plus an internal filter that’s typically serviced or replaced by a technician every several months, depending on usage and how dusty the environment is. Regular filter care keeps oxygen purity and airflow consistent.
Choosing the right oxygen concentrator comes down to matching flow rate and delivery mode to your specific prescription, not just picking the most popular model. If you’re still unsure whether you need a 5 LPM or 10 LPM unit, continuous flow or pulse dose, or whether renting makes more sense than buying, our team is happy to walk through it with you — get expert advice before you decide.