N30i airflow

[GreenCan99]

I switched to the N30i last week and it's been a lot nicer to sleep with, but I'm curious about something and am hopeful people here might have some info.

I notice that when it's doing it's cool down in the morning, if the mall is laying funny the airflow is restricted. I totally sleep on my side so one some of the mask is constantly squished. I know Resmed says that the mask compensates for this by sending more air down the other side, but it's that really accurate? I'm on fixed pressure so I'm curious if the air restriction on one side really does affect the pressure delivered to the nose piece. Does anyone have any more accurate info on the airflow and pressure when you are laying on one side of the mask?

[realshelby]

You can completely pinch off one side of the headgear and it does slightly lower the volume of air. Not very much, much less than the Dreamwear headgear for instance. I think the difference in sound of the air flow changing is more of a mental effect than actual pressure/volume changes. A softer foam pillow pretty much eliminates this effect.

From an engineering standpoint you cannot close off one path of flow without some loss of volume. But The P30i/N30i headgear does a pretty good job of minimizing this.

[jnk...]

Flow and pressure are two different things.

Flow is about the intentional leak, or venting, from the mask.

Pressure is about the treatment that actually keeps the airway stable.

How the air gets routed moment to moment should not affect treatment pressure.

[ragtopcircus]

Flow and pressure are two different things.

Flow is about the intentional leak, or venting, from the mask.

Pressure is about the treatment that actually keeps the airway stable.

How the air gets routed moment to moment should not affect treatment pressure.

No, pressure has to be maintained while the flow rate is high (like when inhaling). If the passage is restricted, the the pressure at your nose will be lower than the pressure in the hose.

That said, I’ve found that for the P30i/N30i, the side between my head and the pillow does not completely pinch off.

[jnk...]

pressure has to be maintained while the flow rate is high

Which is exactly what the blower is designed to accomplish--the delivery of appropriate pressure throughout breathing, despite the breathing itself and the intentional leak from the mask.

If the passage is restricted,

Which can't happen unless you somehow lie on both sides of your head at once. The mask is designed to allow for maintaining treatment pressure(s) even if only side of the mask delivery tubing is available.