O2 Bottle vs Portable Battery Pwr'd O2 Concentrator

[gmcjetpilot]

So these things are popping up on TV. I have heard others use these medical devices, they are fairly light, compact and run on 12 volts DC internal or external power.
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Anyone use these. What does the FAA say about using these to meet FAR 91.211 Supplemental oxygen. They are FAA approved for passengers on airlines. The most compact sized portable units produce 630 to 1250 ml/min O2. Some produce 3L or more. I assume current draw and size of unit is proportional to O2 output.

They extract the ambient O2 available and concentrate it. They weigh 3 to 6 lbs, depending on output desired. The size is well under that of a small O2 bottle. I called one company and they say they can make their spec output up to 10,000 feet. They run time on battery alone was 5 hours, but at higher output (as you might need at higher altitudes) is 2 hours. With 12 volt cable it can run indefinitely.

 

[msires]

Most if them have an altitude limit, have to check the specs to see if they would work. The FAR just says supplemental oxygen is required, doesn't say how it has to be made available.

 

[climberrn]

Have Aerox cylinder installed, but my wife used an Inogen G5 on a XC trip this summer. We brought both so we could fly high coast to coast without needing refill round trip.

The Inogen was keeping her SPO2 up at 16.5K. They have a service life, and don't last forever. Ours showed an error a few times indicating need for service, and overheated a couple of times. She had to hold it in front of the air vent to cool it off. As for the DC adapter, we did not bring the AC charger and that caused issues. The Inogen battery is 18V, and the charger only provides battery voltage ~14.5V. The battery charge went down slowly while plugged into 12V, its more of a range extender. I don't like the additional cords in the cockpit to deal with.

On a later trip, we bought a new battery and the AC charger, and kept it plugged in while the plane was running. Brought it to the hotel and charged it overnight. That worked much better. In my plane I much prefer a bottle for simplicity and reliability (we have a fill system in the hangar). If we had to pay $50-100 for a fill I might lean toward the Inogen.

The 5 hour run time you mentioned is probably with the larger battery, on setting 1. The standard battery on level 3 is closer to an hour on ours.

 

[rv8ch]

My experience with the Inogen One G5 is very limited - only about 10-20 flights, normally below 10k for about 2-2.5 hours, but some flights up to 14.5 for periods of about an hour. I try to use O2 any time I know I'll be over 7k, or might be. I just leave it in the aircraft all the time.

Mine seems to stay at 100% charge with the 12v car charger. I think it is a DC-DC step-up converter. I have not not noticed an increase in temperature, but at the altitudes where I fly with the unit on, the temp is pretty low. I also run it on 3 or 4 (out of 6). I got some Y splitters recently so if I get someone in the back on one of my longer flights, I'll see what kind of performance we get with two people.

About the weight, I can't imagine that the G5 weighs less than a bottle system - the G5 is pretty small but massive. I have not weighed it, and the website says 4.7 lbs, but it feels heavier. Perhaps I'm just a weakling.

Inogen have a new one "Rove 6" but I can't see what's different about it from the G5.

I'm really happy with the G5, but I have zero experience with bottle systems, so I can't compare and contrast them.

 

[Jetmart]

The Inogen unit is used a fair bit in GA. High use and with very good comments on the BeechTalk forum. If your seriously considering using I would join the Beechtalk forum and read the following.

https://www.beechtalk.com/forums/viewtopic.php?f=7&t=220575&view=unread#unread

https://www.beechtalk.com/forums/viewtopic.php?f=35&t=223751

https://www.beechtalk.com/forums/viewtopic.php?f=34&t=224689&view=unread#unread

Consumer Aviation article:

https://www.dropbox.com/s/2u2r2itl8wje3jf/AviationConsumer_O2_Concentrators.pdf?dl=0

 

[bobnoffs]

not sure but i think the concentrators actually remove nitrogen and what is left is mostly o2.

 

[BobTurner]

not sure but i think the concentrators actually remove nitrogen and what is left is mostly o2.

This is correct. The air is run over a bunch of columns made of a specific chemical composition, that preferentially absorbs nitrogen, leaving oxygen behind for the user. I guess there must be a small pump to push the O2 to the user. Periodically the columns need to be re-charged, e.g., they are heated to drive the N2 out, then they start over. This is where most of the heat cones from, and what the electricity is used for.

 

[KRviator]

Kitplanes did a writeup on them a decade ago and seemed favourable. Down here in the nanny-state, we can't buy one new without a prescription it seems, but there's always dozens for sale privately. I'm seriously thinking about getting one for going into the flight levels.

 

[BH1166]

Im a retired Respiratory Therapist. You can only use a concentrator in the presence O2. Less up at altitude means less it can concentrate and deliver. If necessary for flight, Id go with a bottle. If at 10,500 likely keep your O2 saturation in 90’s with healthy lungs. Pretty sure it’ll do ok for healthy lungs a bit higher but can’t say. YMMV. Oh, an on demand/pulse delivery is best in all cases, all systems with healthy lungs or not, IMO

 

[gmcjetpilot]

Thanks for replies... Imogen said their units provide the required O2 spec they are made to 10,000ft. What specs are those? One would have to use it, measure your blood O2 Sat at altitude (carefully), see if it works. They have different settings, which uses more electrical power. Of course individuals are different....

Prescription. Yep that is true required. Many companies will get you a prescription. You could also buy used and doubt they ask for prescription. This is not a big road block. Some of this has to do with insurance, but I recall to buy medical O2 bottles requires a prescription.

Even if not legally required Supplemental O2 is nice to have on a long cross country even below 12,000 feet.

As far as 18V power.... you can get a bucking or boost converter and turn 14 volts to 18 volts. You could get an inverter and use the wall power supply. One unit I saw had two external battery packs... From post above and 3 hours of battery power. So two battery packs 6 hours, say a day flying and charge at night. As said using the 12V power cable will not charge but only extend the battery life in a car or plane.

Speaking of DC to AC inverters, they AC powered units, which are a tad bit larger and a pound or two heavier. They are also less expensive. Again an inverter might be reasonable. When compairing to an O2 bottle and regulator, they seem to be in the same ball park.

 

[Kyle Boatright]

I actually had an agreement to buy a used G5 a couple of weeks ago that I backed out of. If I didn't plan on going over ~15K' and my primary use was in a 2 seater, the G5 with a splitter would be a reasonable bet. Even if it only allowed me and a passenger to go to (and stay at) 13-14K' with good saturations.

But my sense is I'd need two G5's for the -10, so might as well use a bottle and the cheap refills at the local welding supply store.

 

[BillL]

PSA Technology

The units are PSA - pressure swing technology where two parallel columns are pressurized and purged. The heat of adsorption facilitates the repeated regeneration. There is no reason the process won't work at altitude, the air compression pump just has to be sized for the expected altitude range.

Bob's were right . . . purge nitrogen and get oxygen. Same media, just capture the blowdown (adsorbed element) and pass the main flow. I got 10 lb media for $80 including outrageous shipping. 2 lb would be generous for a pair of pilots.

I went down the rabbit hole on this tech last week and amazon delivered a pile of parts to make a -100F dew point dryer today.

The cost of the molecular sieve for oxygen is not that expensive but the compressor may be the most difficult specs to meet - would need 100 psi up FL180. This probably means series compressors . . . not a big deal per se, but management of the absolute pressures across the media beds would be the trick. No real technical hurtles to make a portable 12 VDC unit to do all this. Any "builder" can do it. Just to a little research.

https://www.youtube.com/watch?v=AE5QOq-HN3U start at 2:05

I will continue to use a compressed oxygen bottle. Very reliable.