Oxygen Masks and Canulas

[Guest]

Hi,

I am trying to find a source of masks and canulas for an oxigen system built into a Mooney M20K.  Does anyone know a source for purchase?

I am getting close to purchasing the M20K, and I want to be ready.

Thanks, Sid

[Hank]

Many people like this:

https://www.mhoxygen.com/product-category/built-in/

Paul @gsxrpilot can probably recommend which parts he uses in his K. 

[KLRDMD]

https://www.preciseflight.com/general-aviation/shop/oxygen-equipment-general-aviation/products/masks-cannula/

[exM20K]

For the mask, I’d spend the money on one with a microphone built in.

https://www.aerox.com/4110-712-microphone-mask-assembly-approved-to-tso-c103/

A little more up-front money saves on refills and is much more comfortable. 
https://www.mhoxygen.com/product-category/portable-pulse-demand/o2d2/

I have their boom cannula mounted to my Bose A20, and that is very satisfactory.

the pulse systems work like a SCUBA regulator.  They pulse a blast of air when you inhale rather than running constantly.  It is much more comfortable and way less drying.

your factory system uses Scott fittings.

-dan

Edited December 27, 2020 by exM20K

[gsxrpilot]

1 hour ago, Hank said:

Many people like this:

https://www.mhoxygen.com/product-category/built-in/

Paul @gsxrpilot can probably recommend which parts he uses in his K. 

Thanks. I use the Mountain High O2D2 system. It's important to note that the masks/cannulas need to match the system you select. For example, the Aerox mask won't work with the MH O2D2 system. 

I like the O2D2 system for many reasons but the reason I bought it was to save on O2 refills. Not that O2 is expensive, but it's a hassle to have to refill it after each trip. Now I get three or four trips out of each refill. When I'm above FL180 I'm wearing the MH Mask with the Mic built in. It's easy to drop my Halo headset down around my neck and wear the mask unobstructed. It's surprisingly comfortable even on the long trips. 

I also like the reassuring sound the O2D2 makes with each breath. Just like a SCUBA regulator as @exM20K said, there is a burst of air with each breath. If I don't hear the sound, I'm immediately checking to make sure O2 is flowing. 

[jlunseth]

The miked mask is a must if you go above 18k. Expensive, but works. I have the Aerox. When I got it I found that the mike is installed vertically and it really needs to be horizontal, across your mouth. I was able to bend it, then it worked fine.

I have found the pouch type cannulas to be mediocre. You are supposed to be able to crank the O2 down, there is a separate scale on the O2 flow meter for that type cannula. But I simply use the regular scale. The oximeter (you need to get one by the way) was telling me the O2 flow was no different than an ordinary cannula.

Oximeters are available at the drug store for less than aviation sources. Your O2 minimum should be 92%, higher than that is better.

[shawnd]

When I picked up my M20K 252 this past summer, I called Precise Flight and got their kit. Their oxymizer coupled with the A5 flowmeter kept me high on O2 at 16,500. Their support is also phenomenal. Since I am VFR pilot, haven't gotten the chance to test out the masks yet. @KLRDMD has the link above.

 

Just as a note, the M20K (and Mooneys in general I believe) use the Scott connector:

https://www.preciseflight.com/general-aviation/shop/product/all-one-connector-kit/images/scott-style-connector/

See another thread for details:

 

So be sure to get the right ones!

 

[Guest]

 I am a little overwhelmed with your thoughtful responses.  I will let you all know what I do.  I am looking forward to this airplane adventure.  Even if this Mooney purchase doesn’t work out I will persist.  It looks good though.  It is a 1983 with midtime engine, the wastegate upgrade, intercooler and nice avionics. I go out  to see the plane 16 Jan, do a test flight to 17k, prebuy and then close if all goes well.  Then the challenge is finding a hangar.

[carusoam]

Welcome aboard Shoyt!

You just found out how wonderful a community can actually be...

One day you will have the answer to somebody else’s question!

+1 on knowing which connector you have, and which ones are in the plane... depending on who changed what last... you may get a close, but, not quite right connector...

Mistakes with O2 systems can be hazardous the higher you fly...

Best regards,

-a-

[Guest]

Thanks for the warning about the connectors.  And thanks to everyone for responding.   I agree it is serious business.  I look forward to being part of the community.  

[eman1200]

Holy shoyt, lotta good info in this thread.

[StevenL757]

11 hours ago, exM20K said:

For the mask, I’d spend the money on one with a microphone built in.

https://www.aerox.com/4110-712-microphone-mask-assembly-approved-to-tso-c103/

A little more up-front money saves on refills and is much more comfortable. 
https://www.mhoxygen.com/product-category/portable-pulse-demand/o2d2/

I have their boom cannula mounted to my Bose A20, and that is very satisfactory.

the pulse systems work like a SCUBA regulator.  They pulse a blast of air when you inhale rather than running constantly.  It is much more comfortable and way less drying.

your factory system uses Scott fittings.

-dan

@shoyt,   This....^

[RJBrown]

The onboard system as the factory made it is very inefficient. It uses way too much oxygen. I used the floating ball regulator to feed an oxymizer cannulas. With a battery powered oximeter on your finger to double check for safety.  
In addition to the on board system I always carried a portable Sky-Ox system for back up. I made up adapters to allow use of both medical E type bottles and regular welding bottles. The Sky-Ox bottle had to be sent in to be filled and I was responsible to keep it in date. Medical E and welding bottles are exchange for full, no wait. 
I was caught in Dallas on a Sunday unable to refill once. Really limits your choices.

when flying high solo I always had a back up set up and ready to go on the passenger seat.

read this https://aviation-safety.net/wikibase/38638

[Jerry 5TJ]

34 minutes ago, RJBrown said:

 
In addition to the on board system I always carried a portable Sky-Ox system for back up....

I also carried a backup bottle.  When above 18,000 and a second person is on board I have them use the portable bottle for redundancy.  

[PeteMc]

The connector is the main item you need to be concerned about.  Pretty much any mask will "work" if you have the right connector.  My '80 K's factory O2 uses Scott Connectors, so there is a good chance yours will too.  If the owner has masks now, ask them to send you a Pic of the connector.  And the mechanic that did the pre-purchase should also know what kind of system is in the plane you're looking at.

Here's what my connector looks like: https://www.preciseflight.com/general-aviation/shop/product/all-one-connector-kit/images/scott-style-connector/

And as others have said, be sure to get one of the Oxymizer type cannulas (big mustache).  They will really save you O2 and are much more comfortable when flying below FL180.  ALSO, make sure you get the correct flow meter for the Oxymizer. The standard flow meter will still just have you putting out way more O2 than your breathing.

If you're going to venture into the FLs, the mask with the mic will make life much easier.

[louisut]

Another vote for the Mountain High O2D2 EDS units.  It's by far the most efficient--more so than the oxymizer + flowmeters and much more so than the factory constant flow. At ~$100 per O2 fill in your K, it should pay for itself eventually. With the EDS, you don't need a special conserver cannula. Any regular cannula (albeit with the right narrow tube at the end) will work; they cost about $8 from MH directly.

To use the EDS with ship O2, you'll also need an appropriate regulator. Here's the kit that includes everything: https://www.mhoxygen.com/product/o2d2-x-str/ The regulator has a Scott fitting inlet on one end and the outlet to the EDS on the other. I also have a USB power cable which powers the EDS unit, so no batteries required.

If you're cheap like I am, email MH and ask if they have any refurb units. They have them on occasion and practically speaking they're as good as new.

One upside of the portable system is that O2 from welding supply stores is cheaper. There used to be a difference between medical, aviation, and industrial O2, but no longer. This can also save money over getting O2 from the FBO + recurring inspections for your factory O2. If you already have a factory system installed though, might as well use it since you're already taking the hit on weight.

Edited December 28, 2020 by louisut

[PeteMc]

I didn't know that much about the MHOxygen systems, so I did some checking. 

According to their sales team, the On-Demand System (O2D2 orO2D1) will save an additional 40% over just using the Oxymizers with the built in system (Mooney). 

Anyone know if this is true?  That's a pretty substantial savings and it might be worth the investment if most of your flights are in the teens or FLs. 

 

[M20F-1968]

I never quantified the svings, but I would not doubt the 40% quoted.  The O2D2 is a must have system.

John Breda

[louisut]

22 hours ago, PeteMc said:

I didn't know that much about the MHOxygen systems, so I did some checking. 

According to their sales team, the On-Demand System (O2D2 orO2D1) will save an additional 40% over just using the Oxymizers with the built in system (Mooney). 

Anyone know if this is true?  That's a pretty substantial savings and it might be worth the investment if most of your flights are in the teens or FLs. 

 

It's a reasonable number. Their system only delivers a pulse of O2 on your inhale. In contrast, traditional systems deliver O2 constantly on both the inhale and exhale, and so you end up wasting about half your O2.

The only downside I can think of is that it's an electronic device. If it fails or runs out of power, then it won't deliver O2. However, I think that if it fails, it's more noticeable because you won't feel the puff. It requires less active attention than having to constantly check a flowmeter.

Edited December 31, 2020 by louisut

[PeteMc]

i would *hope* the device either defaults to full flow or has some sort of alarm that it is not functioning correctly. 

On the O2 savings, I'm actually surprised at the claim of 40% savings over Oxymizer Cannulas.  This number would not surprise me at all with the use of regular cannulas.  But the point of the Oxymizers is to reduce the flow so that, in theory, there is little or no wasted O2 coming out of the tank.  The reservoir is supposed to allow you to use a much lower flow and capture the flow between breaths and during your exhale.  Then you get the same amount of O2 as if the unit was at the higher rate for regular cannulas with the continuous flow just going out into the cockpit.  

So I would have not been surprised if there had been some savings, but 40% seems... um... surprising.  Hence my question if that made sense to people that know of actual daily use of the device.

 

[aviatoreb]

One really good feature of the O2D2 pulse delivery system when used with a mask with a built in mic - you hear every breath you breath like Darth Vador breathing, which is very useful because then with every breath you KNOW there is O2 being delivered.  Plus the system has an alarm sound if the O2 is stopped.

With a cannula (and far and away an oxyarm cannula is comfortable and convenient), you don't get the same sound feedback of breathing but you do feel a puff of air in your nose a pulse of delivering O2 when using the O2D2 vs free flow where I always wonder if it is working.

[exM20K]

28 minutes ago, PeteMc said:

i would *hope* the device either defaults to full flow or has some sort of alarm that it is not functioning correctly. 

O2D2 does not revert to full flow.  It will stop working.  I have never run it all the way down, but I expect the low battery alarm is obvious.  I carry extra batteries and the MH standby bottle, which, sadly, seems to be discontinued.  It is similar to this: https://www.mhoxygen.com/product/boost-oxygen-5-liter/

 

 

-dan

[shawnd]

i would *hope* the device either defaults to full flow or has some sort of alarm that it is not functioning correctly. 
On the O2 savings, I'm actually surprised at the claim of 40% savings over Oxymizer Cannulas.  This number would not surprise me at all with the use of regular cannulas.  But the point of the Oxymizers is to reduce the flow so that, in theory, there is little or no wasted O2 coming out of the tank.  The reservoir is supposed to allow you to use a much lower flow and capture the flow between breaths and during your exhale.  Then you get the same amount of O2 as if the unit was at the higher rate for regular cannulas with the continuous flow just going out into the cockpit.  
So I would have not been surprised if there had been some savings, but 40% seems... um... surprising.  Hence my question if that made sense to people that know of actual daily use of the device.
 

I have been using my Oxymizer recently in combination with a pulse oximeter and from what I see it works great. 3.5 hr usage by single pilot set to altitude 3-4K higher than flown and not much O2 consumed (I didn’t measure but maybe one tick if that). All the time my O2 levels were at 93-96.

I had a faulty oxymizer and that errored to full open when I was ferrying my plane from AZ to WA. Nothing like breathing FL280 levels of O2 at 16.5. Called precise flight up and they replaced all 4 units, oxymizer, flow meter and masks - no questions asked. Gotta love that.

Checking my O2 level as part of my flow keeps me active during a long flight and so far has been working out well. Of course I am sub 18K so my attitude might change once I break that barrier.

[EricJ]

3 hours ago, louisut said:

It's a reasonable number. Their system only delivers a pulse of O2 on your inhale. In contrast, traditional systems deliver O2 constantly on both the inhale and exhale, and so you end up wasting about half your O2.

The reservoir in oxymizer-style cannulas is there to take up the slack so that the flow is closer to what you need than 2x.   When you're exhaling it inhibits the flow from the cannula, so the reservoir continues to fill, and when you inhale it pulls from the reservoir rather than the flow rate just during the inhale. 

Ordinary medical cannulas don't have the reservoir, which is why they're not recommended unless you're using a pulse-demand system like an O2D2.   If you use an oxymizer cannula with a pulse-demand system, the reservoir prevents the controller from seeing the pressure difference between inhale/exhale and can't generate the pulse properly when needed.    This is why it's important to match the cannula/mask to the system appropriately.

 

[jaylw314]

4 hours ago, PeteMc said:

i would *hope* the device either defaults to full flow or has some sort of alarm that it is not functioning correctly. 

On the O2 savings, I'm actually surprised at the claim of 40% savings over Oxymizer Cannulas.  This number would not surprise me at all with the use of regular cannulas.  But the point of the Oxymizers is to reduce the flow so that, in theory, there is little or no wasted O2 coming out of the tank.  The reservoir is supposed to allow you to use a much lower flow and capture the flow between breaths and during your exhale.  Then you get the same amount of O2 as if the unit was at the higher rate for regular cannulas with the continuous flow just going out into the cockpit.  

So I would have not been surprised if there had been some savings, but 40% seems... um... surprising.  Hence my question if that made sense to people that know of actual daily use of the device.

 

Back of envelope calculations:

Rebreathing cannulas and masks conserve O2 when the flow rate is low enough that it does not fill the reservoir between breaths.  Once it does, any further O2 flow spills out during exhalation and is wasted.  The cannulas with mustache-type cannulas hold about 25 cc (estimate), and a typical breathing rate is 15 breaths a minute.  That means a flow rate up to 0.5 L/min is conserved.  Any excess flow past that works like a normal nasal cannula, wasting about 50% of the O2 during exhalation.

The upshot is that at low flow rates, demand regulators are probably no better than rebreathers.  However, above a certain flow rebreathers no longer conserve, where demand regulators conserve at any flow rate.  I suspect MH makes their claim about savings vs rebreathers at high flow rates, which would be correct, of course.

If you figure rebreathers lose their benefit past 0.5 L/min, we can figure that is about 10% of the minute ventilation in the lungs (4-5 L/min with normal respiration).  That gives you about 50% of your O2 at sea level from supplemental oxygen at this flow rate.  At 10,000', not only do you lose 30% of your O2 from air, but 0.5 L/min gives you 30% less oxygen as well.   So you can get the same O2 at sea level with full conserving flow from that rebreather only up to 10,000'.  At 15,000', you lose 50% of your O2 and your conserving flow is 50% less, so that amounts to getting only 75% of your sea level O2 (or about the actual oxygen supply at 8,000').

A larger reservoir may partly offset this limit, but I suspect there are problems with larger reservoirs (CO2 accumulation?), so this might be the practical limit to reservoir size for sustained use.

Most of the above numbers are guestimates or pulled from memory, so take with a grain of salt.

TL;DR - Yes, demand regulators are better than rebreathing cannulas, but 40% better probably only happens at higher altitudes.

Edited December 31, 2020 by jaylw314