# Question about oxygen machines **URL:** \ **Category:** Factual Questions\ **Created:** [December 28, 2012, 1:58pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381 "2012-12-28T13:58:09Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![brujaja](https://avatars.discourse-cdn.com/v4/letter/b/4af34b/32.png) [@brujaja](https://boards.straightdope.com/u/brujaja)\ **Post date:** [December 28, 2012, 1:58pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/1 "2012-12-28T13:58:09Z")
There is an apparatus one can obtain if one’s doctor recommends oxygen supplementation for you. --Of course, you can simply get the tanks too; but they get expensive, so the machine is for when you’re home and you don’t need your oxygen supply to be portable. As I understand it, the machine sucks in a quantity of the ambient air, and I believe what it does is compress the air to remove what isn’t oxygen, then delivers the oxygen to the patient. I may have some of these details wrong. My main question is, what happens to the moisture present in the air the machine intakes? Is it disbursed along with the other non-oxygen components? Or does it collect somewhere? Thanks! ---
**Author:** ![BubbaDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bubbadog/32/333_2.png) [@BubbaDog](https://boards.straightdope.com/u/BubbaDog)\ **Post date:** [December 28, 2012, 2:31pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/2 "2012-12-28T14:31:21Z")
I actually had one of those. I turned it on for about 30 seconds and then realized that having extra oxygen while I sleep wasn’t going to help me much if I had to sleep next to a machine that sounded like a running lawn mower. I signed the forms that said I was returning it against medical advice and got the damn thing out of my house. Sorry I’m no help. I posted this with the hope that whoever answered your question would possibly address the noise issue that these little machines from hell provide. ---
**Author:** ![ed\_anger](https://avatars.discourse-cdn.com/v4/letter/e/bbce88/32.png) [@ed\_anger](https://boards.straightdope.com/u/ed_anger)\ **Post date:** [December 28, 2012, 2:35pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/3 "2012-12-28T14:35:20Z")
> [@BubbaDog](#): > > I actually had one of those. I turned it on for about 30 seconds and then realized that having extra oxygen while I sleep wasn’t going to help me much if I had to sleep next to a machine that sounded like a running lawn mower. my mother-in-law has one of these machines with a 30+ foot oxygen cable so she can walk around the house while still getting oxygen, you can put it in another room if the noise bothers you that much. there is also different models, some may have less noise. as to the OP, i don’t think the air gets significantly compressed enough for there to be excess moisture. the machines i’ve seen never have condensation on them. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [December 28, 2012, 2:44pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/4 "2012-12-28T14:44:09Z")
[Oxygen Concentrator at Wikipedia.](http://en.wikipedia.org/wiki/Oxygen_concentrator#How_oxygen_concentrators_work). > [@](#): > > An oxygen concentrator has two cylinders filled with zeolite pellets. Air is compressed to a few times normal atmospheric pressure (typically 20 psi/138 kPa gauge, or 2.36 atmospheres absolute) and passed through the zeolite bed. The bed adsorbs the nitrogen, leaving nearly-pure oxygen (plus small amounts of argon, CO[sup]2[/sup], water vapor and other minor atmospheric components) in the output. So it just removes Nitrogen. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [December 28, 2012, 2:46pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/5 "2012-12-28T14:46:01Z")
My wife uses one, it’s not real loud. The air is compressed and run through a bed of [zeolite](http://en.wikipedia.org/wiki/Zeolite) pellets which absorb the nitrogen. The remaining oxygen is run through a water-filled bottle on the way to the user. ---
**Author:** ![brujaja](https://avatars.discourse-cdn.com/v4/letter/b/4af34b/32.png) [@brujaja](https://boards.straightdope.com/u/brujaja)\ **Post date:** [December 28, 2012, 3:59pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/6 "2012-12-28T15:59:22Z")
A water-filled bottle? Hmmm. That’s kinda what I was wondering about. What happens to any airborne vectors that get sucked into the machine? Snagged in the zeolite? Is it impossible for them to wind up in the water? P.S. Call me weird – I like the sound it makes. It makes me think of Mike Mulligan and his Steam Shovel. 🙂 ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [December 28, 2012, 4:04pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/7 "2012-12-28T16:04:32Z")
> [@brujaja](#): > > A water-filled bottle? Hmmm. That’s kinda what I was wondering about. \*\* What happens to any airborne vectors that get sucked into the machine? Snagged in the zeolite? Is it impossible for them to wind up in the water?\*\* > P.S. Call me weird – I like the sound it makes. It makes me think of Mike Mulligan and his Steam Shovel. 🙂 No idea. My wife doesn’t catch colds anymore often than before and the water gets refilled about every 36 hours(more or less). Doesn’t look cloudy. ---
**Author:** ![Ferret\_Herder](https://avatars.discourse-cdn.com/v4/letter/f/e47774/32.png) [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)\ **Post date:** [December 28, 2012, 4:26pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/8 "2012-12-28T16:26:54Z")
You realize any airborne vectors would also risk being sucked into a far more ideal incubation environment, namely, the human in question? 🙂 ---
**Author:** ![BubbaDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bubbadog/32/333_2.png) [@BubbaDog](https://boards.straightdope.com/u/BubbaDog)\ **Post date:** [December 28, 2012, 5:50pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/9 "2012-12-28T17:50:43Z")
> [@ed\_anger](#): > > my mother-in-law has one of these machines with a 30+ foot oxygen cable so she can walk around the house while still getting oxygen, you can put it in another room if the noise bothers you that much. there is also different models, some may have less noise. I was supposed to be using it for sleep only. It also came with a thirty foot hose But the only place to move the machine was down the hall which made the hose perfectly convenient for tripping over in the middle of the night. My CPAP machine is whisper quiet. The concentrator was a little louder than my loudest snore was before I got the CPAP. I’m pretty sure it would have driven my lovely wife right out of the bedroom. Until I can find a machine as quiet as my CPAP I’m just going to do without the oxygen. I’m lucky that my O2 condition is not critical so going without is something I can get away with. ---
**Author:** ![brujaja](https://avatars.discourse-cdn.com/v4/letter/b/4af34b/32.png) [@brujaja](https://boards.straightdope.com/u/brujaja)\ **Post date:** [December 28, 2012, 7:45pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/10 "2012-12-28T19:45:11Z")
> [@Ferret\_Herder](#): > > You realize any airborne vectors would also risk being sucked into a far more ideal incubation environment, namely, the human in question? 🙂 Well, that’s what I was kinda curious about. The machine I’m talking about isn’t hooked up to any water supply … not sure how an internal water bottle would empty and refill otherwise? Also, in a poorly-ventilated room, does it deplete the oxygen in the air any faster? ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [December 28, 2012, 7:55pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/11 "2012-12-28T19:55:50Z")
> [@brujaja](#): > > Well, that’s what I was kinda curious about. The machine I’m talking about isn’t hooked up to any water supply … not sure how an internal water bottle would empty and refill otherwise? > > Also, in a poorly-ventilated room, does it deplete the oxygen in the air any faster? It’s an external bottle, similar to [this.](http://www.mountainside-medical.com/products/Bubble-Humidifier-350cc%2C-Empty-6-PSI-with-Safety-Pop-Off-Alarm.html) I can’t imagine a room that poorly ventilated, it would almost have to be sealed. Home units max out at 10 liters O2 per minute. ---
**Author:** ![MsBatt](https://avatars.discourse-cdn.com/v4/letter/m/c68b51/32.png) [@MsBatt](https://boards.straightdope.com/u/MsBatt)\ **Post date:** [December 30, 2012, 12:29am UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/12 "2012-12-30T00:29:54Z")
The water bottle is there not to catch germs but to moisturize the air the patient is breathing. When my mom forgets to refill hers, her nose gets so dry it bleeds. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [December 30, 2012, 6:36am UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/13 "2012-12-30T06:36:33Z")
Typically 5A or 13x mol seives are used in oxygen concentrators. Also - all mol-seives are usually dessicants - that is they absorb water since it is a smaller molecule. There are lots of different ways you can add moisture back to the generated oxygen before inhaling. Some of the ways are bubbling through water, misting, etc. Typically you will add water (distilled) to these humidifiers. Keep the humidifiers clean since they can be breeding grounds for bacteria. ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [December 30, 2012, 6:39am UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/14 "2012-12-30T06:39:55Z")
> [@ZenBeam](#): > > [Oxygen Concentrator at Wikipedia.](http://en.wikipedia.org/wiki/Oxygen_concentrator#How_oxygen_concentrators_work). > So it just removes Nitrogen. ZenBeam - that may need some correction on Wikipedia. Typically zeolites are dessicants, so they will remove moisture. I am not an expert on oxygen concentrators, but the only way I can think of them not absorbing moisture is that somehow they get saturated with water and the water is not getting removed in the regeneration cycle. I doubt this maybe happening - but I could be wrong. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [December 30, 2012, 2:20pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/15 "2012-12-30T14:20:07Z")
zeolites because of their high surfaces area are used for many purposes where large amount of surface or long microscopic paths are needed. being a sponge for many small substances is one of them. ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [December 30, 2012, 4:12pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/16 "2012-12-30T16:12:45Z")
I’m sort of interested in this for health/wellness reasons as opposed to medical need. So I was doing some research and it seems that there are both concentrators and generators. The concentrators have been thoroughly discussed here, so thank you to everyone who contributed. I think the generators have been mentioned too, but those I’m a little unsure about. They seem to use a molecular filter rather an adsorbent like zeolite. I guess these aren’t that efficient at high flow rates so if you want 90% O2, most small units only produce 1 liter per minute. They produce 30% O2 at 3-5L/min I think. But normal O2 concentrations are 21% so that doesn’t really seem like much. I like the idea of being able to select a given concentration but then again, I’m sure that can be achieved with a concentrator too just by adjusting the air/O2 mix. Also, while the generators seem to be readily available, a lot of the concentrators seem to be rental units, so I’m wondering if you need a prescription for those. You definitely don’t for the generators since the ones on ebay ship from China or Australia. Finally, the generators are a bit cheaper. The low end Devilbiss Igo model seems to sell for around $500 at Sears whereas the generators are less than $400 including shipping (no tax). So for someone who just wants to suck on some pure O2 like after a workout or for a mental boost, etc. which type of unit should I look at? Do I even have a choice if one requires a doctor’s authorization? Thanks. ---
**Author:** ![Morgenstern](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@Morgenstern](https://boards.straightdope.com/u/Morgenstern)\ **Post date:** [December 30, 2012, 4:27pm UTC](https://boards.straightdope.com/t/question-about-oxygen-machines/645381/17 "2012-12-30T16:27:58Z")
> [@ZenBeam](#): > > [Oxygen Concentrator at Wikipedia.](http://en.wikipedia.org/wiki/Oxygen_concentrator#How_oxygen_concentrators_work). > So it just removes Nitrogen. Which is what, 78% of ambient air. That’s a major concentration of O2 then.