Are CPAP masks are supposed to vent pressurized air?

[Rip Van Winkle]

Sorry for the newb question, but while in use, my Mirage Quattro full face mask continually vents pressurized air through the small pin holes located near the top of my nose. It is continuous and actually blows on my wife, enough to blow her hair around. I understand there has to be someplace for exhaling but I just want to know if the constant pressurized air should also be venting as well.

thanks

[DreamStalker]

Yes it does. As you correctly noted, thereneeds to be venting of exhaled CO2.

Pressure is still maintained with venting as long as venting is always less than machine airflow.

[PST]

Sorry for the newb question, but while in use, my Mirage Quattro full face mask continually vents pressurized air through the small pin holes located near the top of my nose. It is continuous and actually blows on my wife, enough to blow her hair around. I understand there has to be someplace for exhaling but I just want to know if the constant pressurized air should also be venting as well.

Yes, that is how it is designed to work. It ensures that exhaled air is flushed away and you always inhale new air. The blower is designed to take this venting into account. This is one of the admitted inconveniences of CPAP. Setting a small pillow between your head and your wife's can help. There are masks that aim the flow of air differently than the Quattro does. In general, people get used to this. I think it ranks lower than leakage and sore noses in most people's list of adjustment problems.

[LinkC]

I think it ranks lower than leakage and sore noses in most people's list of adjustment problems.

I does on my list!

But my spousal unit ranks it somewhere between reflexively kicking her in my sleep and f*rting while facing the other way (the end result of aerophagia...).

[DoriC]

I keep a pillow propped up between us so I don't feel the exhaust air from my hubby's mask but I never experienced my hair actually blowing. Maybe someone can answer if that is because your pressure is higher than his(12cms) or could it be coming from leaks? Sounds curious.

[billbolton]

I understand there has to be someplace for exhaling but I just want to know if the constant pressurized air should also be venting as well.

The Carbon Dioxide in your exhaled breath needs to be removed from the mask promptly, so you do not rebreath it. This achieved by a technique called scavenging, which relies on the Venturi effect to extract a precentage of the air volume in the mask on a continuous basis.

So, yes, the mask must be constantly venting pressurised air. The air flow rate for scavenging purposes is published in the manufacturer's specification for each mask (though its sometimse hard to find, depending on what they call it).

Cheers,

Bill

[dsm]

Prior to the quattro, the Ultra Mirage mask blew the air out even more forcefully ! -- the quattro added lots of smaller holes to try to spread the exhausting of the air.

Good luck

DSM

[billbolton]

but I never experienced my hair actually blowing. Maybe someone can answer if that is because your pressure is higher than his(12cms) or could it be coming from leaks? Sounds curious.

Vent design in masks is a complex issue. A fairly straightforward explanation goes along these lines....

• 1. There needs to be enough airflow to perform succesful scavenging at the lowest flow rate
  
  2. The air needs to go through smallish holes to get the Venturi Effect at the right level to achieve adequate scavenging for the entire volume of air in the mask (so bigger masks need more)
  
  3. Pressurised air moving through smallish holes tends to create noise and that needs to be managed carefully, as there are enough "light sleepers" who are senstive to noise that it is a non-trivial customer issue
  
  4. The direction that the air emerging from the vents, now moving at high speed, needs to be managed to avoid disturbing the sleeper and any sleeping partner.

Since points 1 and 2 MUST be managed , the only things that can be "traded off" in a design sense are points 3 and 4.... and point 3 is going to be higher priority than point 4.

It is actually somewhat more complex than that but, those are the highlights.

Here's one "war story" from the design space that I am aware of..... the Fisher and Paykel HC405 mask uses a filter on the vents, which makes it both very quiet and disperses the higher pressure exhaust flow so that it does't really "blow" anywhere much, and is an elegant design solution, but F&P didn't repeat the design feature in later masks as users complained about having to replace the filters, as they go black quickly around the vent holes. However, the HC 405 is still in enough demand to stay in the F&P product line, despite 2 further turns in the product design cycle (HC406/407 and Zest) for that style of mask

Cheers,

Bill

[Rip Van Winkle]

Ok thanks everybody, I just wanted to make sure I was PAPn' correctly

[DoriC]

Prior to the quattro, the Ultra Mirage mask blew the air out even more forcefully ! -- the quattro added lots of smaller holes to try to spread the exhausting of the air.

Good luck

DSM

I seem to remember,among other problems, that was one of Mike's complaints when trying the Quattro, there didn't seem to be enough air circulating inside the mask and he felt a little suffocated.The Q did sound much quieter. It's hard for me to know. Could that have something to do with his shallower breathing pattern? He does tend to breathe more quietly anyway since adjusting to his therapy with the UMFF and no more thrashing about with apneas. BTW,dsm, love your photo, you look quite dashing!

[torontoCPAPguy]

I understand there has to be someplace for exhaling but I just want to know if the constant pressurized air should also be venting as well.

The Carbon Dioxide in your exhaled breath needs to be removed from the mask promptly, so you do not rebreath it. This achieved by a technique called scavenging, which relies on the Venturi effect to extract a precentage of the air volume in the mask on a continuous basis.

So, yes, the mask must be constantly venting pressurised air. The air flow rate for scavenging purposes is published in the manufacturer's specification for each mask (though its sometimse hard to find, depending on what they call it).

Cheers,

Bill

There are many considerations with respect to exhaust vents to be sure but the MAIN consideration seems to be the venting of carbon dioxide (or at least a percentage thereof) so you do not rebreathe it.

Different masks will have different methods of venting in terms of where the vent hole(s) are located and so on and as a result will blow exhaust air in different directions and at different sound levels. I (we) find the Mirage Activa LT to be just fine, for instance and most of today's manufacturers have recognized these considerations to the extent that it is almost (almost) a non-issue. The vent holes must NOT be blocked under any circumstances!

Regards

[RoninHouston]

Yes and ResMed puts the Pressure -Flow Curve on page 7 of your manual, i.e., determine your pressure and the chart will tell you the Flow Rate is L/min.

[Rip Van Winkle]

The vent holes must NOT be blocked under any circumstances!

Don't worry, I'd never block the holes - just thought I had something adjusted or set incorrectly. Thanks for the info everybody...I guess since my perscription calls for a setting of 16 (which I guess is on the high side) this could be why my mask vents like a leaf blower Don't get me wrong, the wife is VERY understanding and has no problem - I just felt bad. Well it seems like my cool new mask is working correctly - this forum is a great resource

[BCMiles75]

Sorry for the newb question, but while in use, my Mirage Quattro full face mask continually vents pressurized air through the small pin holes located near the top of my nose. It is continuous and actually blows on my wife, enough to blow her hair around. I understand there has to be someplace for exhaling but I just want to know if the constant pressurized air should also be venting as well.

thanks

I'm new too so please forgive me if I'm posting in the wrong place. I have a question about CPAP masks venting also. I have a ResMed F20 mask and I can't find vent holes anywhere. Since I have COPD in addition to OSA, I'm very worried about more carbon monoxide in my body. This is the only mask available for my machine, which is a ResMed Airsense 10. Does anyone have a F20 mask who can help me with this?

[Pugsy]

I'm new too so please forgive me if I'm posting in the wrong place. I have a question about CPAP masks venting also. I have a ResMed F20 mask and I can't find vent holes anywhere. Since I have COPD in addition to OSA, I'm very worried about more carbon monoxide in my body. This is the only mask available for my machine, which is a ResMed Airsense 10. Does anyone have a F20 mask who can help me with this?

Welcome to the forum.

Who told you the F20 was the only mask available for your machine?....that's not correct. Just about any mask, brand or type can be used with your machine.

The F20 does have vent holes...it's up by the little elbow thing...hard to see if you don't know what you are looking at and where to look. The little holes in the white ring thing that I circled...those are the vent holes.

f20vent.JPG