Inogen has been a leader in the portable oxygen concentrator industry, producing one of the first portable oxygen concentrators in 2004. Since the original Inogen One concentrator, Inogen has improved their design twice and now offers both the Inogen One G2 and Inogen One G3. I will review these two POCs together.
The Inogen One G2 and G3 are pulse only portable oxygen concentrators, using a minute volume delivery method. This means that they will provide a fixed amount of oxygen each minute regardless of your breathing rate. If you breathe faster, you get less oxygen per breath; if you breathe slower you get more oxygen per breath. The Inogen One G2 provides up to pulse setting 5, while the Inogen One G3 provides up to pulse setting 4.
Both models come standard with the Inogen One G2 or G3 concentrator in an attractive carry bag, AC and DC adapters for home and car, one (1) rechargeable battery in your choice of size. The Inogen One G2 also comes standard with a wheeled cart.
Inogen is the only company that offers two battery options – a small battery that keeps the weight down (7.5 pounds for the G2 and 5 pounds for the G3), or a large battery that lasts twice as long, but does increase the weight a bit (9 pounds for the G2 and 6.25 pounds for the G3). Most retailers will provide additional batteries at a discounted price when you add them to the purchase of your Inogen One.
Optional accessories include an external battery charger and backpack.
Both models are FAA approved for airline travel.
Inogen One G2 and G3 – What I like:
- Dependable – Inogen is known for quality manufacturing, with fewer service issues than with most other POCs
- Quiet motor – Inogen units have noticeably quieter motors than other POCs
- Two battery size options – you decide which is most important, lighter weight or longer duration
- Pulse flow settings of 1-2-3-4-5 for the G2 and 1-2-3-4 for the G3 (UPDATED 11/1/13: The Inogen One G2 now provides up to setting 6. The amount of oxygen per breath at 20 breaths/minute:
- Setting 1 = 10.5 mL
Setting 2 = 21 mL
Setting 3 = 31.5 mL
Setting 4 = 42 mL
Setting 5 = 52.5 mL (G2 only)
Setting 6 = 63 mL (G2 only)
- Setting 1 = 10.5 mL
- Inogen One G3 is the smallest portable concentrator providing up to pulse setting 4
Inogen One G2 and G3 – What I wish were better:
- Noisy purging sound on the G3 – Only the Inogen One G3 has this issue. The purging sound, which is the noise produced by the unit when it exhausts the non-oxygenated air, is rather loud. The unit purges about once every 15 seconds. Many people are not bothered a bit by the noise; others are quite distracted by it. The G3 is not a unit you would want to take to a quiet place like a fine dining restaurant or the theater. I have heard that Inogen is working on this issue, but do not know when it will be resolved.
A special note about the Inogen One G3 and the Sieve Columns
An unusual feature of the Inogen One G3 is that it has sieve columns that can be replaced by the patient. The sieve is the part of the concentrator where the oxygen is concentrated. In all POCs, the sieve will wear out and need to be replaced. All other POCs, including the Inogen One G2, cover the sieve under the standard warranty for the unit (usually 3 years); therefore, the manufacturer will cover the replacement of the sieve within the warranty period, but charge upwards of $400 for replacement once the unit is out of warranty.
The Inogen One G3 sieve columns have only a one-year warranty, yet are expected to need replacing about every 24-30 months. Since this is out of the warranty period, yet prior to unit’s 3-year warranty, Inogen has designed them to be easily replaceable by the patient. The pair of columns is expected to be around $150 and would be available for purchase as an accessory item.
At first I viewed this as a design flaw. Why would Inogen knowingly produce sieve columns that would not last as long as on other models? However, I now see the advantages. Knowing that the sieve of all POCs will need to be replaced shortly after the unit is out of warranty, the cost of replacing the sieve columns on the G3 is fairly low when you consider the cost to replace a sieve on other models. And since you can replace the sieve columns yourself, you do not have the hassle of having to send your unit off to the manufacturer for service.
All-in-all, apart from a caution with regard to the purging sound of the G3, I would highly recommend both the Inogen One G2 and the Inogen One G3 for oxygen users who are looking for a small, lightweight unit that provides a pulse flow of oxygen.