Summary of Oxygen Concentrator Liter Flows (2024)

The oxygen provided by home and portable concentrators can be dispensed in one of two ways, commonly referred to as either Continuous Flow or Pulse Flow delivery. Both of these oxygen delivery methods provide medical-grade oxygen directly to the user; however, the dosage is measured differently for each method of oxygen flow. Below we will contrast the two oxygen delivery methods and highlight the devices that feature them, this will help you and your physician determine what type of oxygen delivery is best suited for your lifestyle and oxygen requirements.

Continuous flow oxygenflows without interruption from the cannula and only stops when the concentrator is turned off. These continuous flow concentrators will deliver the same amount of oxygen through the cannula regardless of the patients breathing patterns. This type of oxygen delivery allows the flow rate to be measured at a constant volume of LPM (liters per minute).

Pulse dose oxygen concentrators are engineered to dispense oxygen when the machine senses inhalation. A “pulse” dose of oxygen, referred to as a “bolus”, is triggered and released when a patient inhales through a cannula. Pulse dose oxygen machines have “settings” that indicate how much oxygen is dispensed each minute. The amount (milliliters) of oxygen received by the patient (in a minute) will vary with the manufacturer, the setting, and the patient’s breathing (inhalation) rate. The size of the bolus of oxygen dispensed increases when the settings are increased.

It should be noted that while the manufacturers designed a setting of 2 on a pulse dose machine to approximate 2 LPM on a continuous flow machine, these are NOT the same. We recommend all patients considering a pulse dose machine both discuss the pros and cons with their doctor AND test the unit for efficacy to their specific needs.

Each model of portable oxygen concentrator has a “maximum oxygen output” which defines the maximum amount of oxygen a given machine can deliver (regardless of setting or breath rate). Similar to a car’s horsepower, this is a good measure of a machine’s “capacity” to provide medical-grade oxygen. The maximum oxygen output for each machine is listed in Exhibit 1 below.

Exhibit 1:Portable oxygen concentrators (POC) and their oxygen output in pulse dose settings and ml/min.
Note: The table is for educational purposes only. Oxygen output in pulse dose settings is not directly comparable to continuous liter flow.

Pulse dose delivery was originally designed to allow for smaller machines and longer battery life. As such, many smaller portable models only offer pulse dose settings, while some larger models feature dual-mode and offer both continuous flow and pulse delivery.

Your Oxygen Prescription

If you require oxygen therapy, your doctor will prescribe you a given oxygen flow rate such as 2 liters per minute. An oxygen flow rate of 2 LPM means the patient will have 2 liters of oxygen flowing into their nostrils over a period of 1 minute. Oxygen prescriptions generally run from 1 liter per minute to 10 liters per minute with 70% of those patients being prescribed 2 liters or less.

It is important to consult with your physician regarding your specific oxygen requirements, both at rest and exertion. Determining the correct therapeutic dose for both daytime and nighttime use will allow our Oxygen Specialists to assist you in selecting the right equipment when renting or purchasing your own concentrator. We recommend patients discuss with their doctors their ability to use a pulse dose versus a continuous flow machine and the recommended settings on each machine.

If you are upgrading to a newer model of a concentrator, then please check with your physician whether your oxygen requirements have changed. We highly suggest purchasing an oxygen concentrator that can deliver oxygen higher than prescribed to accommodate the changing needs.

Below is a summary of various home and portable machines that feature one or both of the delivery methods available.

Portable Oxygen Concentrator Pulse Settings

Exhibit 2: Most Popular Portable Oxygen Concentrators in 2020 and their Highest Pulse Dose Setting
Note: Apple is shown in the image to show relative size.

Inogen G4

• Currently the smallest, lightest, and most portable unit available
• Settings: 1 to 3
• Battery Life: Up to 2 hr 40 min (with single battery)
• Weight: 8 lbs (with single battery)
• Dimensions: 2.68 x 7.2 x 5.91 (W x H x D in inches, with single battery)
• Maximum oxygen output: 630 ml/min on pulse dose
• Best for: Active lifestyles and mobility
• Click here for more information on Inogen One G4

ResMed Mobi

• Currently has the best battery life
• Settings: 1 to 4
• Battery life: Up to 6 hr (setting of 2, with internal battery)
• Weight: 5.5 lbs (with battery)
• Dimensions: 9.6 x 7.95 x 4.49 (W x H x D in inches)
• Maximum oxygen output: 680 ml/min
• Best for: Long trips and no hassle of switching batteries
• Click here for more information on ResMed Mobi

Inogen One G3

• Currently the most widely used portable oxygen concentrator
• Settings: 1 to 5
• Battery life: Up to 4 hr 40 min (with single battery)
• Weight: 4.8 lbs (with single battery)
• Dimensions: 3 x 8.25 x 8.75 (W x H x D in inches, with single battery)
• Maximum oxygen output: 1050 ml/min
• Best for: Active lifestyle
• Click here for more information on Inogen One G3

Respironics SimplyGo Mini

• Currently has the best user interface and display
• Settings: 1 to 5
• Battery life: Up to 4 hr 30 min (setting of 2, with standard battery)
• Weight: 5 lbs (with standard battery)
• Dimensions: 3 x 9.4 x 3.6 (W x H x D in inches, with standard battery)
• Maximum oxygen output: 1000 ml/min
• Best for: Daily chores and family visits
• Click here for more information on SimplyGo Mini

Caire Freestyle Comfort

• Currently has the best ergonomics
• Settings: 1 to 5
• Battery life: Up to 4 hr (setting of 2, with single battery)
• Weight: 5 lbs (with single battery)
• Dimensions: 7.3 x 10 x 3.1 (W x H x D in inches, with single battery)
• Maximum oxygen output: 1050 ml/min
• Best for: Carrying on your shoulders
• Click here for more information on Freestyle Comfort

Inogen One G5

• The latest device from Inogen
• Settings: 1 to 6
• Battery life: Up to 6.5 hr (with single battery)
• Weight: 4.8 lbs (with single battery)
• Dimensions: 3.26 x 8.15 x 7.19 (W x H x D in inches, with single battery)
• Maximum oxygen output: 1260 ml/min
• Best for: Active lifestyle and travel
• Click here for more information on Inogen One G5

Respironics SimplyGo

• Most versatile unit available
• Settings: 1 to 6 (Continuous flow also available)
• Battery life: Up to 3 hr (setting of 2, with standard battery)
• Weight: 10 lbs (with battery)
• Dimensions: 11.5 x 10 x 6 (W x H x D in inches)
• Maximum oxygen output: 1440 ml/min (on pulse dose)
• Best for: Single unit solution that is great for all-around daytime and nighttime use
• Click here for more information on SimplyGo

Caire SeQual Eclipse 5

• Most powerful and versatile unit available
• Settings: 1 to 9 (continuous flow also available)
• Battery life: Up to 5 hr 6 min (setting of 2, with standard battery)
• Weight: 18.4 lbs (with battery)
• Dimensions: 12.3 x 19.3 x 7.1 (W x H x D in inches)
• Maximum oxygen output: 2304 ml/min (on pulse dose)
• Best for: Those needing higher flow rates of oxygen or wanting more headroom
• Click here for more information on Eclipse 5

Home (and Portable) Oxygen Concentrator Liter Flows

Exhibit 3: Most Popular Home Oxygen Concentrators in 2020 and their Highest Liter Flow
Note: Apple is shown in the image to show relative size.

Respironics SimplyGo

• Most versatile unit available
• Liter Flow: 0.5 to 2 LPM (pulse dose also available)
• Battery life: Up to 1 hr 36 min (on 1 LPM, with standard battery)
• Weight: 10 lbs (with battery)
• Dimensions: 11.5 x 10 x 6 (W x H x D in inches)
• Maximum oxygen output: 2 LPM (on continuous flow)
• Best for: Single unit solution that is great for all-around daytime and nighttime use
• Click here for more information on SimplyGo

Caire SeQual Eclipse 5

• Most powerful and versatile unit available
• Liter Flow: 0.5 to 3 LPM (pulse dose also available)
• Battery life: Up to 3 hr 40 min (on 1 LPM, with standard battery)
• Weight: 18.4 lbs (with battery)
• Dimensions: 12.3 x 19.3 x 7.1 (W x H x D in inches)
• Maximum oxygen output: 3 LPM (on continuous flow)
• Best for: Those needing higher flow rates of oxygen or wanting more headroom
• Click here for more information on Eclipse 5

Inogen At Home 5L

• Currently the smallest stationary oxygen concentrator
• Liter Flow: 1 to 5 LPM
• Power Consumption: 275 W Maximum
• Weight: 18 lbs
• Dimensions: 13 x 16.5 x 7 (W x H x D in inches)
• Maximum oxygen output: 5 LPM
• Best for: Low power consumption and taking along while traveling
• Click here for more information on Inogen at Home

Respironics EverFlo Q

• Currently has the quietest stationary oxygen concentrator
• Liter Flow: 0.5 to 5 LPM
• Power Consumption: 350 W Maximum
• Weight: 31 lbs
• Dimensions: 15 x 22.8 x 9.5 (W x H x D in inches)
• Maximum oxygen output: 5 LPM
• Best for: Those needing low-maintenance and quiet nights
• Click here for more information on EverFlo Q
• EverFlo Q with Oxygen Percentage Indicator, EverFlo Q OPI, monitors oxygen purity and alerts when purity degrades

Caire Companion 5

• Easy-to-Use
• Liter Flow: 0.5 to 5 LPM
• Power Consumption: 350 W Maximum
• Weight: 36 lbs
• Dimensions: 12.5 x 21.5 x 13.5 (W x H x D in inches)
• Maximum oxygen output: 5 LPM
• Best for: Daily routine at home
• Click here for more information on Companion 5

Invacare Platinum 10

• Currently has the best user-friendly design
• Liter Flow: 2 to 10 LPM
• Power Consumption: 585 W Typical
• Weight: 53 lbs
• Dimensions: 18 x 26 x 14 (W x H x D in inches)
• Maximum oxygen output: 10 LPM
• Best for: 24-hour oxygen needs
• Click here for more information on Platinum 10
• Platinum 10 with SensO2 monitors oxygen purity and alerts when purity degrades

Respironics Millennium M10

• Currently has the best oxygen liter flow range
• Liter Flow: 1 to 10 LPM
• Power Consumption: 600 W Average
• Weight: 53 lbs
• Dimensions: 13.3 x 26.8 x 18.9 (W x H x D in inches)
• Maximum oxygen output: 10 LPM
• Best for: Reliable operation and safety alerts
• Click here for more information on Millennium M10
• Millennium M10 with Oxygen Purity Indicator monitors oxygen purity and alerts when purity degrades

Caire AirSep NewLife Intensity 10

• The best unit to run with a nebulizer or use in conjunction with a hyperbaric chamber
• Liter Flow: 2 to 10 LPM
• Power Consumption: 600 W
• Weight: 58 lbs
• Dimensions: 16.5 x 27.5 x 14.5 (W x H x D in inches)
• Maximum oxygen output: 10 LPM
• Best for: High-pressure application at 20 psi and usage with up to 200 feet long tubing
• Click here for more information on Intensity 10

Discontinued Oxygen Concentrators

Advancement in technology has benefitted us with smaller, lighter, quieter, and more powerful oxygen concentrators, making the old ones obsolete. In this section, we state some of the obsolete oxygen concentrators worth a mention. So, if you have been using these concentrators and want to upgrade to the next gen, then find the comparable oxygen concentrator in the sections above.

Portable Oxygen Concentrators

• Setting Range 1 – 3 – AirSep Focus and AirSep Freestyle
• Setting Range 1 – 4 – Lifechoice Activox by Inova Labs
• Setting Range 1 – 5 – Inogen One G2, AirSep Freestyle 5, and Invacare XPO2
• Setting Range 1 – 6 – Respironics EverGo and iGo by DeVilbiss

Home Oxygen Concentrators

• 2 Liter per Minute – Respironics SimplyFlo
• 5 Liter per Minute – Invacare Perfecto and AirSep Visionaire

Disclaimer: Information on this page is for educational purposes only. For more information, talk to your doctor or primary care provider.

Updated: August 29, 2023
Published: October 2, 2014

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