O2 conservation - MH vs SkyOx

Discussion in 'Flight Following' started by Skepilot, Feb 7, 2021.

  1. Skepilot

    Skepilot Pre-Flight

    Joined:
    Jul 11, 2017
    Messages:
    76
    Location:
    Atlanta, GA
    Display Name:

    Display name:
    Skepilot
    Looking at the various O2 conserving systems for operating at FL180 and below. Everyone seems to rave about Mountain High, but check out this comparison:

    - Mountain High 4-place system with a 15-cu ft cylinder is $2200.
    - SkyOx 4-place system with a 15-cu ft cylinder is $638
    - With the Mountain High O2D2 EDS system, at 15,000', that 15 cu ft will last 12.3 man-hours.
    - With the SkyOx Oxymizer cannula, at 15,000', that 15 cu ft will last 13:48 man-hours.
    Similarly, for the larger tanks:
    - MH 24 cu ft: 20.2 man-hours
    - SkyOx 24 cu ft: 22:42 man-hous

    Also: The Mountain High O2D2 EDS requires batteries or USB power, whereas the SkyOx Oxymizer does not.

    Now, when you go over FL180 and you need to ditch the Oxymizer cannula and switch to masks, then the MH will have the advantage. But, if flying only at FL180 and below, I can't see spending the extra money for MH. Am I missing something?

    Sources:
    Duration:
    https://www.mhoxygen.com/chart/
    http://www.skyox.com/.../OxygenCannulaInstructions1.pdf
    Pricing:
    https://www.mhoxygen.com/product/o2d2-system-eds-oxygen/
    http://www.skyox.com/product/SK 12-15
     
    wayneda40 and masloki like this.
  2. GRG55

    GRG55 Final Approach

    Joined:
    Dec 29, 2015
    Messages:
    9,288
    Display Name:

    Display name:
    Aztec Flyer
    I use a SkyOx in the Aztec. My theory is simpler systems are more reliable (fewer failure modes). And in an airplane reliability is important.
     
    Skepilot likes this.
  3. Peter Anderson

    Peter Anderson Pre-takeoff checklist

    Joined:
    Mar 16, 2018
    Messages:
    359
    Location:
    NorCal
    Display Name:

    Display name:
    SVTPete83
    Anothe vote for the skyox. That’s what we use in the RV and the 10lb bottle has lasted long enough for all the trips I have made. During the summer we were flying between 14-16k in an RV.


    Sent from my iPhone using Tapatalk Pro
     
    Skepilot likes this.
  4. Grum.Man

    Grum.Man En-Route

    Joined:
    Jul 17, 2014
    Messages:
    3,332
    Location:
    Statesville NC
    Display Name:

    Display name:
    Grum.Man
    I use skyox as well. I didn’t want to worry about more batteries and rarely get over 17k.
     
    Skepilot and murphey like this.
  5. flyingron

    flyingron Touchdown! Greaser! PoA Supporter

    Joined:
    Jul 31, 2007
    Messages:
    20,201
    Location:
    Catawba, NC
    Display Name:

    Display name:
    FlyingRon
    mountain High is going to blow the doors of a fixed flow regulator as far as bottle life is concerned. The only competition is the Precise Flight Demand Conserver.
     
  6. murphey

    murphey Touchdown! Greaser! PoA Supporter

    Joined:
    Aug 21, 2008
    Messages:
    10,161
    Location:
    Colorado
    Display Name:

    Display name:
    murphey
    Another vote for skyox. There’s no way my cherokee can get to 18k under normal circumstances. However, not unusual for cruise to be 11k-14k
     
    Skepilot likes this.
  7. Skepilot

    Skepilot Pre-Flight

    Joined:
    Jul 11, 2017
    Messages:
    76
    Location:
    Atlanta, GA
    Display Name:

    Display name:
    Skepilot
    Citation needed. I looked into Precise Flight but couldn’t find any endurance numbers in their website.
     
  8. flyingron

    flyingron Touchdown! Greaser! PoA Supporter

    Joined:
    Jul 31, 2007
    Messages:
    20,201
    Location:
    Catawba, NC
    Display Name:

    Display name:
    FlyingRon
    Precise Flite will last over 20 hours on a bottle. MH didn't believe that number when I baked them off against PF, but they realized they could do it too.
    Oxygen is cheap until you run out. Frankly PF and NH are a toss up in my opinion. Either one is better over fixed flow.
     
  9. Skepilot

    Skepilot Pre-Flight

    Joined:
    Jul 11, 2017
    Messages:
    76
    Location:
    Atlanta, GA
    Display Name:

    Display name:
    Skepilot
    You say 20 hours on a bottle but don't say what size. Why doesn't Precise Flite publish their endurance numbers? SkyOx can also get you 20+ hours on 22 cu ft or larger bottle. Like MH, Precise Flite is a fortune compared to SkyOx. PF wants $1750 for a 4-place system, and that doesn't include the bottle. Why spend the extra $1,000+ for MH or PF with no advantage in endurance?
     
    wayneda40 and Grum.Man like this.
  10. PlasticCigar

    PlasticCigar Pre-takeoff checklist

    Joined:
    Sep 25, 2018
    Messages:
    283
    Display Name:

    Display name:
    Plastic Cigar
    My experience with Skyox was not nearly as impressive as those numbers claim.

    With MH I fill my oxygen tank once a year during the annual and I use oxygen on every flight above 5000 ft.

    That being said, oxygen is cheap so do whatever makes you happy. I hate getting the tank filled so the MH system works for me.
     
  11. Racerx

    Racerx Line Up and Wait

    Joined:
    May 15, 2020
    Messages:
    622
    Display Name:

    Display name:
    Ernie
    Old post from Dr Bruce...

    Go to a welding shop or a medical supply shop and BUY outright the biggest Aluminum cylinder you can- a Super "D" or 50 cu. ft. Why? Because a fill of the smallest compared to the biggest runs the $13.00 up to $18.00. Getting the fill is the inconvenience.

    Buy a stepdown regulator (welding type) for ~$40 and put it on top. Buy an 8 foot piece of 80 PSI hose and the appropriate CGA 540 fittings (or have the shop do it for you) and run from the end of the stepdown regulator to another CGA 540 fitting. At this end, buy a Skyox regulator and install it. The Skyox regulator is expensive ($200) but is a precision machined device that automatically doubles flow if two are plugged in, triples for three, etc. It doesn't leak and it's near bulletproof.

    Now you have a tank strapped down in the baggage compartment, and complete control in between the PIC seats.

    This way you have 1) huge O2 supply, = 30 man hours at 18,000 on cannulas e.g, more than you have fuel, and on some trips you will be able to make the return w/o a refill.

    Fill it at your local welding shop. Yes, I know all about ABO, but they all come from the same 25,000 gallon tank. Even medical oxygen, too.

    I also carry a 19 cu ft. steel tank that is labeled "ABO" for that emergency refill at an FBO. I use it when I have six on board (The Skyox has four ports). Total cost will be about $300. And, I spend ALL my time in the oxygen altitudes.

    I agree with the advice to buy a pulse oximeter. It's the cheapest monitor for the only master processor w/o a backup device- your head. There's nothing from King or Garmin near the price...well, maybe a blind encoder.
     
    BillTIZ and CharlieD3 like this.
  12. Racerx

    Racerx Line Up and Wait

    Joined:
    May 15, 2020
    Messages:
    622
    Display Name:

    Display name:
    Ernie
    If you hate getting the tank filled why use oxygen at 5000'? Never heard of people having problems that low. Get a pulse oximeter if you're that concerned.
     
  13. SloRoam

    SloRoam Pre-Flight

    Joined:
    Apr 4, 2019
    Messages:
    85
    Display Name:

    Display name:
    SloRoam
    I have only used mh, which I love.

    Using o2 above 5k is smart, especially for longer flights or at night. And using the mh system, is easy: just turn it on at 5k and it works.
     
    PlasticCigar likes this.
  14. jrollf

    jrollf Pre-Flight

    Joined:
    Sep 24, 2012
    Messages:
    86
    Display Name:

    Display name:
    jrollf
  15. flyingron

    flyingron Touchdown! Greaser! PoA Supporter

    Joined:
    Jul 31, 2007
    Messages:
    20,201
    Location:
    Catawba, NC
    Display Name:

    Display name:
    FlyingRon
    They did publish their numbers (20 hours for a single mask on a 6.3 tank). I do have to admit that PF's current wesite is an awful mess. It was these numbers I showed to MH at Oshkosh. First they scoffed and then they claim the same amount a year later. They also correccted the one feature that PF had that there's was missing. Other than it requiring a 9V battery, I've got nothing against MH even though I have the PF.

    There is a substantial enducrance increase with either PF or MH's demand system. I've got both the PF demand system and the old style flow regulators. They're not even close. As I said, if you're going to fly with small bottles, the demand regulator can be the difference in having enough or not.

    If it's not a big enough deal for you to pay the extra for demand over fixed flow, then don't. But the numbers are real.
     
  16. Skepilot

    Skepilot Pre-Flight

    Joined:
    Jul 11, 2017
    Messages:
    76
    Location:
    Atlanta, GA
    Display Name:

    Display name:
    Skepilot
    Yeah, I have that post bookmarked. I don't I want a cylinder quite that large due to weight and space, but I agree with the rest of the post.

    Yes, I seriously considered that for quite a while. A few problems are:
    1. One concentrator can only supply two people, and then limited to 15,000'
    2. Would have to buy two of them for my family of three. That's $5,000 for two Inogen Aviators!
    3. Running two of them requires 12 amps. That's pushing it for my electrical system.
    4. Can't mount them remotely, as you need access to the controls.
    I totally love the idea of never having to worry about O2 quantity and never having to refill bottles, and if it was just me, I might go that direction. But with a family of three, the down-sides start to add up.
     
    jrollf likes this.
  17. Skepilot

    Skepilot Pre-Flight

    Joined:
    Jul 11, 2017
    Messages:
    76
    Location:
    Atlanta, GA
    Display Name:

    Display name:
    Skepilot
    That would be great if it was 20 hours on a 6.3 cu ft tank! But I can't find those numbers anywhere on their website. I'll email them.

    It's not just a standard fixed flow system I'm comparing it to. It's the SkyOx regulator, recommended in Dr Bruce's post, coupled with pendant-style conserving Oxymizer cannulas. It's just a different way of conserving oxygen. Perhaps not as sophisticated as MH or PF, but the published numbers indicate it's quite effective.
     
  18. PlasticCigar

    PlasticCigar Pre-takeoff checklist

    Joined:
    Sep 25, 2018
    Messages:
    283
    Display Name:

    Display name:
    Plastic Cigar
    Thank you for your unsolicited advice on the proper use of oxygen. As a physician, I am quite familiar with the use of oxygen and own several pulse oximeters.

    The O2D2 has a setting where it will automatically turn on/off at 5000’ pressure altitude. There are multiple benefits to using oxygen at 5000’ and I find this to be quite convenient.
     
  19. BillTIZ

    BillTIZ Final Approach

    Joined:
    Sep 3, 2008
    Messages:
    5,210
    Location:
    ASH, 3B3
    Display Name:

    Display name:
    BTIZ
    I've used both, note the Oxysaver canula in my picture. I transitioned from Oxysaver and flow meters to MH system when I ran out of O2 in 90 minutes at 17K (small tank, I also doubled the tank size). I regularly flew out of 5500MSL airports, DA was already well over 8K on the ground. A 2K tow to 7500MSL, catch a thermal and very quickly through 10K and climbing fast.

    The MH allows the system to be preset to automatically start supplying O2 at either 5K or 10K and automatically adjusts flow as you climb and descend, so you are not always manually adjusting a flow meter. Having it start at 5K MSL gave a good ground check that everything was operational before takeoff and getting older a few hits of O2 after settling into the cockpit on a hot day can be a good thing. Ever takeoff, find out the O2 is not on and you can't reach the tank valve?
     
  20. flyingron

    flyingron Touchdown! Greaser! PoA Supporter

    Joined:
    Jul 31, 2007
    Messages:
    20,201
    Location:
    Catawba, NC
    Display Name:

    Display name:
    FlyingRon
    The conserving canulas have a small reservoir that allows you to potentially set the flow rate a little lower while still delivering the same amount of oxygen. You're still likely dumping a lot of O2 into the cabin in order to keep the things adequately charged. The SkyOx regulator is still a fixed flow rate.
     
  21. BillTIZ

    BillTIZ Final Approach

    Joined:
    Sep 3, 2008
    Messages:
    5,210
    Location:
    ASH, 3B3
    Display Name:

    Display name:
    BTIZ
    Interesting to see/read about this. Previous medical O2 concentrators were not sufficient for use in aircraft as supplemental O2 for the flight crew. The older styles were designed for ground use by patients who needed extra O2. It is good to see that the industry is servicing a need. Now to consider weight, power requirement and space available in a very small single seat aircraft that has no engine driven electrical system. I see they are battery powered with extra battery packs.
     
  22. flyingron

    flyingron Touchdown! Greaser! PoA Supporter

    Joined:
    Jul 31, 2007
    Messages:
    20,201
    Location:
    Catawba, NC
    Display Name:

    Display name:
    FlyingRon
    The problem with most O2 concentrators is they're useless above about 10,000. A few are spec'd to 13K.
     
  23. Jeff Oslick

    Jeff Oslick En-Route

    Joined:
    Mar 12, 2005
    Messages:
    4,143
    Location:
    Fullerton, CA
    Display Name:

    Display name:
    Jeff Oslick
    I have a 4-place SkyOx system, with 22cf "long" bottles. I conservatively figure on 1 cf/per person/per hour for mid-teens altitudes. Stone-simple to use, great system.
     
    wayneda40 and Skepilot like this.
  24. jrollf

    jrollf Pre-Flight

    Joined:
    Sep 24, 2012
    Messages:
    86
    Display Name:

    Display name:
    jrollf
    The one I linked to (Inogen Aviator) is specifically designed and tested for flying in an unpresurized cabin up to 18,000 ft. It is not a regular medical O2 concentrator.
     
  25. Skepilot

    Skepilot Pre-Flight

    Joined:
    Jul 11, 2017
    Messages:
    76
    Location:
    Atlanta, GA
    Display Name:

    Display name:
    Skepilot
    Yes, but the 18,000 ft figure is supplying to one person only. When supplying two people the max altitude is 15,000 ft. And since I have a family of three, I would need two of them.

    I got a reply from Precise Flight. (See attached image.) Definitely not getting 20 hours on a 6.3 cu ft tank. Their numbers are pretty much right in line with MH and SkyOx’s numbers, all within a few percent of each other. I don’t see enough of an advantage to justify the cost differential.
     

    Attached Files:

  26. PaulMillner

    PaulMillner Line Up and Wait

    Joined:
    Jan 14, 2011
    Messages:
    577
    Location:
    Berkeley, CA
    Display Name:

    Display name:
    Paul Millner
    Well, that's true of the Inogen. The Eclipse can handle two to 18,000' reportedly. And of course, the OxyFly can handle 6 people to 18,000'

    [quote[
    Running two of them requires 12 amps. That's pushing it for my electrical system.
    [/quote]
    Ah well... there fixes for that issue, but perhaps you don't want to go there.

    Folks have remoted the Inogen 4 control panel using standard ribbon cable. I don't know if that's been attempted with the latest model.

    [/quote]
    It depends on your mission profiles. Most of my O2 consuming trips are solo, or dual. I use the InogenAviator for myself, and keep bottled oxygen for the occasional fellow travelers. That also provides backup to my concentrator.

    Paul
     
  27. PaulMillner

    PaulMillner Line Up and Wait

    Joined:
    Jan 14, 2011
    Messages:
    577
    Location:
    Berkeley, CA
    Display Name:

    Display name:
    Paul Millner
    Ron, you may want to read the article, above. The aviation (!) concentrators are spec'd to 18,000' and work quite well in my experience.

    Yes, if you buy used sick-room concentrators off Craig's List, made available by the death of old people, you will encounter issues. If you buy an aviation unit designed for 18,000' I think you'll be well served. I've been flying with mine for 5 years now.
     
  28. PaulMillner

    PaulMillner Line Up and Wait

    Joined:
    Jan 14, 2011
    Messages:
    577
    Location:
    Berkeley, CA
    Display Name:

    Display name:
    Paul Millner
    That was not my experience. I found that the oxymizer gave me 3x the endurance of a straight cannula. The O2D2 gives me about 10x the endurance of a straight cannula. Results will vary depending on your personal O2 demand, and how you breathe. This is my data based on a decade of California to East Coast trips, 2 to 3 times a year, in my turbo Cardinal. I then graduated to the InogenAviatior.

    Paul
     
  29. Skepilot

    Skepilot Pre-Flight

    Joined:
    Jul 11, 2017
    Messages:
    76
    Location:
    Atlanta, GA
    Display Name:

    Display name:
    Skepilot
    Sure, but the Eclipse is $3,000, 19”x12” and 18 pounds, and the OxyFly is a 55-pound monstrosity which costs $13,500!

    Well, I suppose the easiest option would be to use battery packs. I can get a third/external generator for my plane, but it seems absurd to go to that extent when there are more practical solutions.

    The folks at Inogen Aviator sent me ideas on remoting, but it required pretty extensive hacking, which of course, voided the warranty.

    Absolutely. It’s a much more attractive solution for solo or dual. I need to support 3 people on nearly 100% of my trips. That said, I haven't ruled it out. I love the idea of never worrying about O2 endurance and the convenience of never having to refill.
     
    Last edited: Feb 17, 2021
  30. Skepilot

    Skepilot Pre-Flight

    Joined:
    Jul 11, 2017
    Messages:
    76
    Location:
    Atlanta, GA
    Display Name:

    Display name:
    Skepilot
    Even Mountain High’s chart doesn’t claim a 10x endurance advantage over straight cannula. Using their chart (which I linked to in the first post), at the 15,000’ example, they claim their O2D2 provides a 3x endurance over straight cannula and a 1.3x advantage over oxymizer cannula.

    When using the oxymizer cannula, what flow rates did you select at which altitudes? Seems the key is to choose the correct flow rate for a given altitude. That rate should just keep the pendant full and limit spillover. Too high of a rate would cause excess spillover and waste O2.
     
  31. PaulMillner

    PaulMillner Line Up and Wait

    Joined:
    Jan 14, 2011
    Messages:
    577
    Location:
    Berkeley, CA
    Display Name:

    Display name:
    Paul Millner
    You can go by the chart, or you can go by real world experience. I think the "slippage" relates to how people use oxygen. Some of us take less frequent deep breaths. Some of us take more frequent shallow breaths. The oxymizer cannula isn't sized to be optimum across that range... to receive enough oxygen in each inspiration bolus, constant flow, oxymizer, and concentrators have to be adjusted differently. Typically, oxygen consumption charts are tabulated with a single assumption about breath depth and frequency. That's perfect if it matches you. If it doesn't, you might want to consider actual field experience, rather than the charts... unless you can re-learn how to breath. I understand that is most difficult.
     
  32. PaulMillner

    PaulMillner Line Up and Wait

    Joined:
    Jan 14, 2011
    Messages:
    577
    Location:
    Berkeley, CA
    Display Name:

    Display name:
    Paul Millner
    As it says in the article, you can find them online, used, for about $850.

    Ah! You need Salvador Dali, A&P, to achieve absurdist accomplishments.

    What kind of airplane and engine are you running?

    I ended up with my freon aircon for my Cardinal because a Bonanza guy and his mechanic were bereft of ideas on how to push more electrons around. I even tried to help them, but they assured me it was hopeless. So... I installed what I'd proposed on my Cardinal, seems to work fine. He sold me the aircon at a steep discount after he failed at generating electrons.
     
  33. Tarheelpilot

    Tarheelpilot En-Route

    Joined:
    Dec 5, 2010
    Messages:
    4,953
    Location:
    North Carolina once again.
    Display Name:

    Display name:
    Tarheelpilot
    If unsolicited advice is a problem for you then you might as well just move on. Unsolicited advice is what makes POA great.
     
  34. Skepilot

    Skepilot Pre-Flight

    Joined:
    Jul 11, 2017
    Messages:
    76
    Location:
    Atlanta, GA
    Display Name:

    Display name:
    Skepilot
    The article I read said $1500 for a used Eclipse. Might find them cheaper now, but your article also warned about degraded performance when buying used. I think if I went the POC route I'm leaning towards two (new) Inogen G5's. I could use one and my wife and daughter would probably be fine sharing the other. The Eclipse could be great if it could supply all three of us, but 1.) I'm not sure it can, 2.) I'm unsure of the amp draw and 3.) the size and weight are still a concern.

    Sling TSi, Rotax 915is. It has dual built-in generators with an option for a third/external generator. I understand the built-in ones provide 30 amps. I'm told a typical IFR panel takes 7amps at idle (not including XPDR replies and COM transmissions) and a heated pitot alone runs 5-7 after it’s warmed up, with a much higher initial current draw while heating up to temp, and the cabin heater can take up to 6 amps. The folks at Inogen Aviator said to count on 6amps for their POC, and I would need two of them.

    However, I have a friend with a Sling TSi who has an Inogen, and he said it takes only 5amps on startup and 3amps continuously. So, I'd probably be OK unless I started them both simultaneously while turning on the pitot heat and transmitting at the same time. ;)
     
    PaulMillner likes this.
  35. ksandrew

    ksandrew Pre-Flight

    Joined:
    Oct 22, 2014
    Messages:
    56
    Location:
    Dawson Georgia USA
    Display Name:

    Display name:
    ksandrew
    Well, we have a dumb country boy here who uses oxygen all the time, a couple of times a week anyway. I am not really sure what you are all talking about. Saving oxygen.

    In my plane I carry 24 cu.ft cylinders and use a fresh one each day or each leg if it is a very long journey. I own 15-20 cylinders that I purchase at estate sales (dead folks don't need oxygen) for about $10 each, I pay Airco to hydrotest, change valve to aviation, and fill for about $30.00. I refill them myself from a 220 cu ft cylinder which goes to the welding shop at 1400 psi. and I get a fresh one.

    When I fly I want to feel that oxygen blowing the hair in my nostrils, no fancy stuff. And to boot I need those cylinders in the baggage area to keep my CG within range.

    My only problem with oxygen, boom mics and a beard is how to eat Southern fried chicken at altitude.

    Life is a barrel of fun.

    Ken
     
  36. Skepilot

    Skepilot Pre-Flight

    Joined:
    Jul 11, 2017
    Messages:
    76
    Location:
    Atlanta, GA
    Display Name:

    Display name:
    Skepilot
    That's great, and a smart way to do it! But, using that same MH chart, a 24 cu ft cylinder without any kind of conserving device will last about 5.6 hours at 18,000'. That's probably plenty if you're by yourself, but if I was carrying my family, we'd run out in less than 2 hours. Sure, you could bring another cylinder for them, and then two more for the return/next leg, but man, I don't have a lot of room in my little Sling! :D
     
  37. ksandrew

    ksandrew Pre-Flight

    Joined:
    Oct 22, 2014
    Messages:
    56
    Location:
    Dawson Georgia USA
    Display Name:

    Display name:
    ksandrew
    Great, so the family all go to sleep and stop bothering you, joking. I always travel alone so is not a factor for me..
     
    Cluemeister and Skepilot like this.
  38. PlasticCigar

    PlasticCigar Pre-takeoff checklist

    Joined:
    Sep 25, 2018
    Messages:
    283
    Display Name:

    Display name:
    Plastic Cigar
    Cute. We’ll have to agree to disagree on what makes POA great. People who know nothing about a subject trying to correct those who do isn’t really my definition of “greatness.” I guess you enjoy that sort of stuff.
     
  39. Tarheelpilot

    Tarheelpilot En-Route

    Joined:
    Dec 5, 2010
    Messages:
    4,953
    Location:
    North Carolina once again.
    Display Name:

    Display name:
    Tarheelpilot
    It’s called sarcasm.
     
  40. PlasticCigar

    PlasticCigar Pre-takeoff checklist

    Joined:
    Sep 25, 2018
    Messages:
    283
    Display Name:

    Display name:
    Plastic Cigar
    It was hilarious.