Best Continuous/Pulse Flow Portable Oxygen Concentrator Rankings - 2021
Updated: September 15, 2021
There are two types of portable oxygen concentrators--the pulse flow and the combination continuous flow/pulse flow models. The pulse flow machines are lightweight and tote in a shoulder bag or backpack. The cart-type concentrators are heavier and travel in a two-wheel frame behind you. Some of the cart-type, continuous flow portables are small and lightweight enough for optional carrying.
Continuous flow oxygen provides a constant flow of oxygen regardless of whether the oxygen patient is inhaling or exhaling. Pulse flow oxygen offers a puff of oxygen when the patient inhales. Continuous/Pulse Flow Portable Oxygen Concentrators (Combination Portable or Combo Portable or CPOC) allow oxygen patients to select either continuous flow or pulse flow mode depending upon their oxygen needs at any given moment.
Portable Oxygen Concentrators that offer both continuous and pulse flow oxygen are on the rise. Just a few years ago, there were only two concentrators that offered this feature--the SOLO 2 and the Eclipse 3. Invacare discontinued the SOLO2 and Sequal (also known as Caire) replaced the Eclipse 3 with the Eclipse 5. Currently, five portables offering continuous/pulse flow are available on the market. These mobile concentrators are the Respironics Simply Go, SeQual Eclipse 5, Oxlife Independence, GCE Group Zen-O, and the DeVilbiss iGo.
A comparison of the Top Pulse Flow Portable Oxygen Concentrators is available by clicking the link. This review provides rankings and comparison charts of the top models on the market for the Best Portable Oxygen Concentrator 2021.
- Portable Oxygen Concentrator Reviews listed by brand compares the top portable oxygen machines on the market.
- Airline Travel with an FAA Compliant Portable Oxygen Concentrator.
- Choosing the Best Travel Concentrator or portable oxygen machine for airline travel.
- What is a Continuous Flow Portable Oxygen Concentrator?
- What is a Pulse Flow Oxygen Concentrator? Exploring the shoulder and backpack concentrators.
- Home Oxygen Concentrator Review and Comparison examine the top ten 5 liter concentrators.
- Ranking the Top Home Oxygen Concentrators with High Flows of 8 to 10 liter home oxygen.
- Low Flow Oxygen Concentrators Review evaluates the home-based machines that offer 3 liters or less.
Reviewing the Best Continuous Flow Portable Oxygen Concentrators 2021 by Size and Weight
Size is an important consideration when purchasing a portable oxygen concentrator for sale. Large, heavy concentrators are more challenging to transport and use while away from your home. Carrying a heavy machine while trying to breathe is too difficult of a task for many oxygen patients. Weight is a significant selection factor regardless of whether you are carrying the concentrator or pulling it behind you. The more the concentrator, battery, and cart weighs, the more of a burden it is to take with you wherever you go.
The most lightweight portable oxygen concentrator is the Zen-O, weighing only 8.8 pounds. Its lightweight allows it to be portable in both carry or cart modes. In the shoulder bag, this CPOC machine weighs 10.73. This weight includes the concentrator, battery, and carry bag. When mounted on the cart, this combo portable weighs 13.51 pounds, including the concentrator, battery, tote bag, and cart. All of these items come standard with the Zen-O. This portable device is the smallest portable oxygen concentrator of the five compared concentrators at only 674 cubic inches. This size is 3-times smaller than the largest concentrator in this study. Its small size and lightweight design make it easier to carry and negotiate narrow shopping aisles, elevators, and doorways.
The second most lightweight is the Philips Portable Oxygen Concentrator called the Respironics Simply Go. It is also a carry- or cart-portable device. In the shoulder bag, it weighs 11.4 pounds, while in the cart, it weighs 13.51 pounds. The cart for the Philips Respironics Simply Go is an optional add-on purchase.
The chart below displays a comparison of the small portable oxygen concentrators for sale by size as well as their weight. The average size for the concentrators displays as a red horizontal line on the chart while the average weight of the concentrator displays as a red vertical line. The area of the chart marked in light red indicates that any concentrator in this area is less than the average weight and less than the average size. Less weight and less size are more desirable. Only the SimplyGo and the Zen-O make the "Red Zone" for being better than average for size and weight. The Oxlife is slightly above average for the weight of a small oxygen concentrator and the iGo is slightly above average for cubic size. Please note that the cart size is not included in the total cubic size of the concentrators except for the Oxlife.
Portable Oxygen Concentrator Size Comparison
Although the Oxlife Independence has the largest footprint of the machines compared, it is the only portable oxygen unit with the cart built into the concentrator cabinet. That means the cart dimensions are part of the 2102 cubic inch size and the 19.5-pound weight. None of the other competitors include the figures of the cart in their product dimensions.
The design of the Oxlife built-in cart is remarkable. It comes with large, recessed 6-inch wheels to handle bumpy surfaces. A folding handle is sturdy and robust. Compared with the easy-to-break telescoping handles and the small wheels of the competitors, the Oxlife is a much better buy if you prefer towing your mobile oxygen behind you.
The benefit of having a one-piece mobile oxygen concentrator is a significant plus. The Oxlife is small enough to fit under the seat of an airplane. The other competitors require removing the cart from the concentrator to fit under the seat. Some models also require removal from the carry bag to change batteries. On the Oxlife, the battery compartment is easily accessible and unencumbered. Another significant feature for the Oxlife is its magnesium metal case that protects the POC oxygen concentrator motor. All of the other machines have plastic cases. The larger size and extra weight associated with the Oxlife contribute to its enhanced durability, sturdiness, and easier operation.
Concentrator Weight with Battery and Cart
Weight is another significant selection factor regardless of whether you are carrying the portable O2 concentrator or pulling it behind you. Since each of these models are battery-operated oxygen concentrators, the weight of the battery and other accessories like the carry bag or cart are all significant. The more the personal oxygen concentrator, battery, and cart weigh, the more of a burden it is to take with you wherever you go. The most lightweight concentrator in this review is the Zen-O, weighing 13.5 pounds with the carry bag, cart, and battery. The SimplyGo is second at 15.2 pounds while the Oxlife Independence is third at 19.5 pounds.
The following chart compares the separate weights for each portable oxygen unit, battery, and cart. The aggregate weight for the machine, battery, and cart displays in all three increments. The machine's weight displays in blue, the battery weight in purple, and the cart weight in gold. For the Oxlife, the cart weight displays as 0 (the gold area) because this weight (the blue area) includes the cart weight, totaling 16.7 pounds. The red horizontal line indicates the average total weight between all five concentrators, mounted on their cart and with their batteries. The most lightweight portable concentrator at 13.5 pounds on the far left, while the heaviest is the iGo at 25 pounds on the far right.
Travel Oxygen Concentrator Weight Comparison
Ranking by Power Consumption
This ranking measures the amount of electrical power the portable oxygen units use to operate. The lower the consumption, the better. In the chart below, the average electricity consumed displays in watts. The least power consumption is 120 watts used by the SimplyGo. Ranking second is the iGo at 130 watts while the Zen-O ranks third at 133 watts. The average watt usage for the five concentrators displays by a red horizontal line at 135.6 watts. The Zen-O, SimplyGo, and iGo have better than average power consumption.
Power Consumption Comparison
Ranking By Battery Duration Time
This section of the review compares the amount of battery time the oxygen patient can expect between recharging. Oxygen concentrators use more energy to run in continuous mode than they do in pulse mode. That means that these portable oxygen concentrators can run for more extended periods between recharging if they are operating in pulse flow mode.
For this review, the battery duration times when the concentrators are operating at setting 2, displays on the chart below. The top line marked in black indicates the rankings for pulse flow use. The bottom line marked in blue shows the rankings for the continuous flow mode. Ranking number 1 for the longest battery time is the Oxlife, which can be powered from its 24 cell battery for 5.75 hours in pulse mode and 2.5 hours in continuous mode. Ranking second is the Eclipse 5 with 5.2 hours in pulse flow and 2.4 hours in continuous flow. Placing third is the iGo with 4.7 hours in pulse mode and 2 hours in continuous. The concentrators that out-ranked the average include the Oxlife, Eclipse 5, and the iGo in both oxygen delivery modes. The Zen-O and the SimplyGo ranked below average.
Battery Duration Rankings
Ranking by Performance
Among the essential criteria in selecting a portable oxygen concentrator is the performance of the oxygen generator. In the performance review, we compare five critical factors: continuous flow output, pulse flow output, oxygen concentration level, oxygen outlet pressure, and maximum operating altitude. First is the oxygen output of each concentrator machine. Three of the concentrators offer 3 liters of continuous flow oxygen while the other two offer only 2 liters. Patients with a prescription above 2-liters of continuous flow should not purchase the SimplyGo or the Zen-O because they will not provide adequate oxygen flows.
The Eclipse 5 ranks first for pulse flow oxygen per minute volume at 192 mL. That is almost twice the volume of the next closest ranking competitor! The Oxlife ranks second with 96 mL while the Zen-O has the lowest oxygen flow at 22 mL.
The next performance comparative is the amount of oxygen concentration. This comparison displays a range and indicates the amount of oxygen supplied as a percentage of the whole. The SimplyGo can produce the highest concentration level of 97%, but can also dip to the lowest concentration range at 86%. For the second rank, the Zen-O has a range of 87 to 96%. The other concentrators are close behind.
The forth comparison element is oxygen outlet pressure. This performance measurement is essential for those who like to use long oxygen tubing with their concentrator. The higher the outlet pressure, the longer the distance the oxygen compressor can adequately push oxygen to the patient. Ranking first for oxygen outlet pressure is the Zen-O at 25 psi. The iGo is second at 15 psi.
The last comparison is the maximum operating altitude for the oxygen concentrators. This element is vital for oxygen patients who live in mountain ranges or plan to travel to an area with high elevations. Three concentrators vie for the first rank position with 13,123 feet above sea level--the Eclipse 5, Oxlife, and iGo.
The chart below displays the data for each concentrator for all five comparative elements. These oxygen devices display in rank order from top to bottom for best performance. The Eclipse 5 is the top-performing portable concentrator followed by the Oxlife and the iGo. The Zen-O, which is the smallest concentrator in the study, has the lowest performance measurements in the comparison.
Best Performance Rankings
|1||Eclipse 5||3||192||87 to 93%||5||13,123|
|2||Oxlife||3||96||87 to 95.6%||5||13,123|
|4||iGo||3||84||88 to 94%||15||13,123|
|5||SimplyGo||2||72||86 to 97%||5||10,000|
|5||Zen-O||2||22||87 to 96%||20.5||9,000|
Many oxygen patients are more concerned about others hearing their loud oxygen machines than they are about themselves having to listen to it. Most oxygen users prefer to use oxygen as discreetly as possible. Each of the six concentrators in this comparison is in the safe, comfortable zone as identified by the Occupational Safety and Health Administration (OSHA). Noise levels below 50 decibels are safe and healthy sounds. A refrigerator operates at around 30 decibels, while the human conversation is 60 decibels. Each of the five concentrators is below 50 decibels. The loudest oxygen machines are the iGo and the Zen-O at 48 decibels. The Eclipse 5 ranked number 1 for the lowest decibels at 40. The chart below shows the safe zone range along with where each concentrator falls for noise level.
Many oxygen patients using only 2-liters of oxygen or less prefer having a single concentrator for their home use as well as for travel. Two of the portable machines in this review can support a 24/7 schedule while a patient is on vacation. These concentrators are the Eclipse 5 and the Oxlife. Because portable oxygen concentrators cost significantly more than a home oxygen concentrator, Vitality Medical recommends purchasing a low-cost 5-liter machine like the DeVilbiss 5L. Use this less expensive concentrator for home use to save "wear-and-tear" on your portable. You can buy four or more home concentrators for the same price as one good portable. Another low-cost alternative is the Invacare Perfecto 2V. While traveling, a suitable 24/7 portable concentrator is a significant factor since the portable is likely to be the oxygen patient's only source of oxygen day and night while they are away from home.
Some portable oxygen concentrators come with additional features that make them a "cut above" the rest of the competition. Some of the concentrators in this review have noteworthy features that make them stand out. For instance, the SeQual Eclipse 5 and the Oxlife Independence can furnish oxygen while also charging off of your car battery. The other concentrators need more power to operate and charge simultaneously than a car battery can provide. The Oxlife Independence and the SimplyGo provide easy access to the battery compartment for a quick exchange to a freshly charged battery. The other models are more cumbersome to conduct battery exchanges, some requiring removing the concentrator from the cart to charge the battery. As mentioned previously, the Oxlife Independence is the only concentrator manufactured with a metal protective case; the others are all made with plastic. Since portable concentrator prices start at $1600 and go up to nearly $5000, protecting your investment with a durable concentrator that can withstand the demands and rigors of travel is a wise choice.
The Eclipse 5 has the best name recognition of the five concentrators compared in this review. It is also the best-selling concentrator. The Oxlife Independence ranks second in recognition and sales. Ranking third is the Respironics SimplyGo.
Overall Best Portable Oxygen Concentrator with Continuous Flow and Pulse Flow
To determine which concentrator is the best, we examined each comparison category, giving the highest priority to performance, second to weight, third to size, and forth to battery time. Performance is the most crucial factor in our rankings because it addresses what a concentrator does--deliver concentrated oxygen to a patient. Size and weight are significant because of the need for the concentrator to be portable. Long battery life impacts the length of time the O2 machine can be away from external power sources. The other elements are also compared but are secondary to these four.
The SeQual Eclipse 5 has the best performance rankings. It shares the number 1 ranking for continuous flow output, has the number 1 ranking for pulse flow output, and shares the number 1 ranking for max operating altitude. The Eclipse 5 ranks second for battery duration time for both continuous flow and pulse flow modes. This device also ranked first for the lowest noise emission. The 24/7 operational capability of the Eclipse 5 concentrator is another important feature offered by this oxygen generator. Only two of the five concentrators compared have the 24/7 feature. Manufactured in the USA, this O2 generator has a low draw on DC power and can operate in your car while also recharging. The overall best portable oxygen concentrator offering both continuous flow and pulse flow is the Eclipse 5. Below is a summary of the rankings highlights for this portable oxygen concentrator.
Best High-Flow Oxygen Concentrator
- #1 Ranking for Continuous Flow Output (shared ranking)
- #1 Ranking for Pulse Flow Output
- #1 Ranking for Max Operating Altitude
- #2 Ranking for Battery Duration
- #1 Ranking for Low Noise
- Low Power Draw, Charges in Car While Operating
- 24/7 Operation
- Made in the USA
- SeQual Eclipse 5
If size and weight are the chief concern for the oxygen patient, they should seriously consider the Respironics SimplyGo. None of the other models in this review are even close to the small size and low weight of the SimplyGo. Currently, it is the only portable oxygen concentrator that you can carry in a backpack or shoulder bag that offers both continuous flow and pulse flow oxygen. However, if you plan to purchase the optional cart for the SimplyGo and prefer to pull the concentrator behind you, the size and weight advantage will disappear. The SimplyGo also ranked number 2 for lowest power consumption at 120 watts (tied with the Oxlife).
The Oxlife Independence is also worthy of praise for its durability and its outstanding record for low repairs and warranty claims. Made with a metal cabinet, it is the most reliable and durable portable concentrator. It is the only portable with a five-year warranty, at least two-years more than any of its competitors. Newer Oxlife concentrators will come with a plastic case to accommodate its new feature--DNA Technology. This feature communicates with the manufacturer to ensure the machine is functioning correctly and to diagnose issues. No other manufacturer incorporates so many durability and reliability features into its oxygen products.
The Oxlife ranked #1 for battery duration, #1 for shortest battery recharge time, #2 for pulse oxygen flow, and tied for #1 continuous oxygen flow. The Oxlife Independence takes 1.5 hours to recharge 1-battery and 2.5 hours for 2-batteries. The built-in cart feature and flip-up handle is also an important feature for those who travel by airline and frequently visit foreign countries.
Vitality Medical also carries Oxygen Accessories for low prices!
Below is a detailed comparison chart displaying each of the comparative factors and the data for each portable oxygen concentrator.
Portable Oxygen Concentrator Comparison Chart (compare side-by-side)
|Continuous/Pulse Flow Concentrators||Zen-O||Respironics
|Manufacturer||GCE Group||Respironics||SeQual||O2 Concepts||DeVilbiss|
|Continuous Oxygen Flow
|Pulse Oxygen Flow
(ave minute volume mL at highest setting)
|Oxygen Concentration||87 to 96%||86 to 97%||87 to 93%||87 to 95.6%||88 to 94%|
|Oxygen Outlet Pressure
(feet above sea level)
(includes carry bag)
|Portable Weight w/o Accessories
|Power Requirements||100 to 240 VAC
19 VDC, 7.9 A
50-60 Hz 2.0 A
19 VDC, 7.9 A
| 100-240 VAC
50-60 Hz, 2.0 Amps
15 VDC, 10 Amps
Europe, UK, China, Australia
|Pulse - 25, 70 charging Continuous - 133, 140 charging||120 not charging
|145||120 not charging
|Battery||12 Cell Lithium Ion||Lithium Ion||12 Cell Lithium Ion||12 Cell Lithium Ion||Lithium Ion|
|Pulse Battery Service Hours
(at setting 2)
|Continuous Battery Service Hours
(at setting 2)
|Battery Recharge Time
|3 to 4.5||3||5||1.5||4.5|
|Preventive Maintenance Check
(after # hours)
|Made In The USA||Yes||Yes||China||Yes||Yes|
(after # hours)
|Warranty||3 Yrs/15,000 Hrs||2 Yrs||3 Yrs||5 Yrs||3 Yrs|
Notes: Each of the concentrators compared comply with FAA airline travel requirements.
Burt Cancaster, Author