Pressure not increasing much due to the air vent holes being large

[CorruptAlligator]

Hi folks,

Recently noticed an issue with my Wisp mask.  I notice that even if I increase pressure, I'm not getting increased air flow to me.  What I notice happens is that the vent just lets out more air!  So, the point of increasing the pressure isn't so effective.  

What I noticed is that with the Respironics Wisp mask, the hose attachment with the vent doesn't have consistent vent sizing.  I notice a difference between two hose attachment vent sizes.  One was larger than the other.  The larger one vents more air out and thus it reduces the pressure when breathing in.  This is indeed a terrible design. And QC issues of the vent size inconsistencies just makes me wonder if they actually care about us getting quality therapy.  

I also question if there is any real scientific intent regarding vent sizing if they cannot keep vent sizing consistent!

One question I have is, what is the repercussions of blocking off half the vent holes?  This way I can get higher pressure, but still would vent out my exhale properly, correct?  Would my CA go up?  Or should I just test to see what happens?  Thanks!

[PaulaO2]

Of course more air is coming out. Because there's more pressure being applied. This is normal.

Do NOT tape up the holes. They are there for a reason.

You may not notice an increase in air to yourself because you have become accustomed to it already.

[CorruptAlligator]

I see what you mean Paula. I wasn't intending to cover all the vent holes, but partial to reduce venting. My question would be, how much vent is adequate. If the vent hole sizing is not consistent, this causes arbitriness. I wonder if there is any way to know the proper vent value, and measure the vent output to match this value?

Also, after using the hose attachment with smaller vent output, my flow limitation has reduced by half. The thing about these machines is that flow limitation is calculated with the shape of the breathing wave? That's probably not highly precise.

[Crimson Nape]

The F&P Evora Full Face Mask has its vents holes in an annoying location.  To diffuse the exhaust air, I use pieces of an A10 filter draped over the holes.  This reduces the noise and diffuses the air stream.  Even though the filter material is just hanging in front of the vents, it also seems to add some back pressure to the mask.  You may wish to explore this concept on your mask.

- Red

[PaulaO2]

vent holes are there for a reason. It allows your CO2 to escape when you exhale. The machine includes this "intentional leak" in its calculations.

Covering them with tape is a bad idea.