Air pressure hurting inside nose

[Walla Walla]

Reznick,
Doesn't work that way. No matter the mask size the machine delivers the same pressure to the mask. It increases and decreases air flow to maintain a constant pressure. The mask setting is only to adjust for leak rate. In fact many people have to increase pressure when switching to a full face mask from pillows. Just the opposite of which you describe. Of course I'm just a dumb high school grad who flunked science.

[Reznik]

Both the Resmed and Respironics machines have a setting for "mask type."  Respironics has x1, x2, x3, etc.  Resmed has Face, Nasal, and Nasal Pillow.  

The machines use that setting to slightly adjust the pressure to account for the difference in static pressure between the different types of masks.  

If you don't believe me, unhook the mask from the hose and change that setting while the machine is running.  You'll see that the pressure increases higher on nasal, and even higher on nasal pillow.

[suzengrace]

Thank you for all your suggestions.. Im  going to  experiment this weekend with tubes, HME etc..and see how it goes... 

Really don't want the longer hose ...not for traveling ... I only use the transcend for travel, etc... so maybe Ill have to figure out reducing (very conservatively) the pressure ...

Again, 

Thank you for your help.

---

[Reznik]

You might also call the manufacturer and ask them.  They might know something, though based upon my experiences calling Resmed, it's doubtful. 

[Sleep2Snore]

It is just like this, if you have worked with gasses like I have, the longer the pipe/hose the less you get in pressure and flow at the other end.
The rougher the pipe, like corrugations as in CPAP pipes the more the air/gases are slowed down.
The larger the pipe the more you will get at the other end, however, if only it were that simple!
However, the larger the pipe the more it takes to fill it in the first place, so it is not quite as simple as it appears.
The narrow pipe as used in CPAP is easy to fill, but due to it narrowness can drop pressure quite a lot, though just to complicate things it takes less to fill it.
I think the main reason narrow pipes are used these days is for cheapness, for no other reason.

The shorter hose will give you a bit more force as there is only half the resistance, though if you sat and worked it out, it might not be quite as much as you think, however, over a few hours this could make a difference to the lining of your poor nose.

No, I am not going to sit and work it all out, not worth getting stressed out doing all the maths!  

[PaulaO2]

My brother works for a flow meter company up in PA. He does field and in-house repairs and calibration. Their meters are mostly used by landfills to track how much gas is flowing. He said they measure it in inches of H2O vs CPAPs cmH2O. They are also used in nearly all Budweiser plants to measure the flow of materials. Which explains Bud's taste... Anyway, I asked him about this and he went to their engineer. The engineer went to the Transcend website to get specifics and tried to figure out a formula. This was his conclusion:

"there are a lot of factors that go into how to figure this out. Perhaps even because the tube isn't rigid would contribute. The best thing to do is just trial and error. Turn it down a little at a time until the problem is solved.''

They had fun trying to figure it out, though! The engineer "needed the distraction" and had fun with it. But, like he said, the variables in coming up with a "one size fits all" formula to determine x length means up/down x amount just wasn't possible, at least with what he had.

He did suggest asking Transcend to see if they know how to adjust it, which they should know.

[Reznik]

I just realized that you'd need another variable in order to computer the correct answer:  Airflow speed.

For any given pipe, the static pressure drop increases as you try to put more air through it.  And again, its not linear.  So, if you double the amount of air you're trying to put through it, the static pressure doesn't merely double.  Rather, the static pressure increases even more.  Static pressure also increases with every curve and bump in the pipe.

So, if you want to do the math, you need to know a lot! 

[suzengrace]

Wow..... Glad theres some experts out there didnt mind taking on this dilemma ...

I really appreciate all the  effort and In-put...

Im going do some experimenting..and also give company a call or email and see what they have to say..

May take a few weeks til I get to this put I will post a follow -up ..

[PaulaO2]

Please do!

Understanding how these things work makes the effort worthwhile, at least for me. It removes the mystery and makes it less intimidating.

And anything else that happens that can't be explained? Aliens.