(06-09-2014, 02:13 PM)scott1965 Wrote: My vents seem to have some kind of coating on them preventing air from escaping.
I can disconnect the mask tube from from the heated line tube, plug the hole at the end of the mask tube, put on the mask and blow air into it and almost no air moves out of the mask-next to nothing comes from the exhalation ports.
When disconnected from the machine and the hose end plugged I need to blow hard enough to blow up a balloon. It was not like this when I got it.
Any one else have this problem or a solution?
After a personal encounter with P10 vent blockage last night, I offer an answer that worked for me and that may help at least some of you who are despairing about the inexplicable behavior of your P10.
Prior to last night my P10 had worked perfectly, and so last night I confidently donned my headgear, gently lowered myself into bed, used the mask leakage function on my CPAP while I adjusted the position of my nasal pillows, and then turned on the CPAP. Immediately I noticed that it was difficult to breathe normally. There was less air than usual available for the inhale part of the breathing cycle, and the air moved less than usual during the exhale. I also observed that the CPAP was making an unusual sound, a brief moaning noise, once during each breath. The CPAP display showed a normal pressure reading. Remembering what other P10 users have reported about vent blockage, I reached my fingers up to the area just in front of my mask and found that there was no detectable air movement. Knowing exactly what normal vent discharge feels like, I immediately concluded that both sides of the P10 vent were blocked.
I considered switching to my full face mask, but I love my P10 so much that I decided to attempt to solve the problem first. Fortunately, I had a wealth of information available in the form of the many contributions to this thread, for which I thank you all. I noticed that at least two people had claimed that they could see a plastic film covering their P10 vents, and so I held my mask up to the light and, sure enough, it looked as though my P10 vent had grown a plastic film. But my mask had been working perfectly less than 24 hours ago! How could this be?
Fascinated, I grabbed a small flashlight, put on my reading glasses, and took a good look at that vent. What I saw was puzzling: I had never seen anything quite like it. Each side of the vent seemed to be a perforated plastic screen with very small holes, with the screens consisting of two or more layers of the same material. The screens were not uniform in appearance, with a large central area the shape of a less-than-half moon and a narrow boundary area that somehow looked different. The vent holes seemed to be larger in the boundary area than in the central area, and I wondered whether the central area was blocked by something, perhaps the plastic film that others had observed. Or perhaps the central area was water trapped between two layers of perforated plastic. I squeezed it between my fingers but the shape and size of the central area did not change. I tried to dry it with a clean, soft washcloth. I tried pushing the bristles of a tiny, soft brush into it. I blew warm air from a hair dryer onto it. Whatever I tried, the water or plastic film or whatever did not change its appearance even slightly.
Obviously I needed to know more about the vent material. One of the early posts in this thread described it as micro-mesh, and so I did a DuckDuckGo search so as to better understand micro-mesh technology. Then I grapped a 14X loupe magnifier and took a much closer look at the P10 vent fabric. Fascinating. It’s essentially a densely packed arrangement of fibers of different thicknesses. The central area is very dense with a lot of very small fibers, and the boundary area is somewhat less dense and lacking the tiniest fibers of the central area, although light still cannot pass straight through it. This inspection under magnification revealed that the appearance of a plastic film or trapped water in the central area of each vent is an illusion caused by the different fiber thicknesses and densities in the central and boundary areas.
Yes, the plastic film is an illusion. So what was blocking my mask? Can you guess?
I found clues to the answer in three places. First, when I took my mask off last night after my brief attempt to use it, I noticed some condensation in the mask and its short hose. Not surprising, because the bedroom temperature was my preferred 55 degrees, but still worth noting.
Second, someone posted that he washes his mask “every night,” which got me wondering whether some people wash their masks in the evening rather than in the morning as I usually do.
Third, my cleaning routine had been interrupted yesterday and it was early evening before I removed my mask from its soaking bowl, rinsed it, shook the water out of the attached hose and set the mask to dry. Several hours later, I connected the mask to the CPAP and turned on the warm-up feature but ended up watching TV in the living room for long enough that the CPAP would have completed its warm-up, held the temperature for a while, and then cooled down again. In the past, when I was using a full face mask, allowing the CPAP to warm up and then cool down again before I put the mask on had sometimes caused a rainout event when I finally went to bed. And so yesterday, not wanting another rainout, I removed the humdifier tank and completed another warm-up to remove moisture from the CPAP, hose and mask. I then replaced the humidifier reservoir and did another warm-up.
Thinking about all this, I realized that it is possible, or even likely, that the micro-mesh vent of the P10 does not dry out as easily as one might assume, and the air blockages are being caused by water temporarily trapped in the micro-mesh fabric. After all, we know that the vent is designed to limit the amount of air that flows through it under pressure, and the vent is made of densely packed fibers. This suggests that the two sides of the vent may behave somewhat like a couple of sponges, but without the option of removing water from the vent by squeezing. Attempts to blow the water out of the vent are futile because the water is securely held in the tiny spaces between the fibers of the fabric by a phenomenon called surface tension. The only way that water is going to escape is by evaporation.
Using my 14X magnifier again, I took a good look to see whether there was any sign of moisture trapped in the vent, or whether evaporation had already changed the appearance of the vent from when I first examined it under magnification. I was encouraged to see that even more tiny fibers were now visible. With increasing hope, I reassembled the mask, connected it to the CPAP, and ran a test. The result was that the mask now operated perfectly and so I went to bed very happy.
Today I performed one further experiment. I immersed one side of the mask frame in tepid water, keeping the other side dry, and then did a side-by-side comparison of the two sides of the vent under 14X magnification. Somewhat remarkably, I could not directly see the water in the wet side, but I could easily tell which side was wet because the smallest fibers were no longer visible as separate and distinct but tended to merge together.
If you want to see a photo that clearly shows what the P10 vent looks like to the naked eye, including the central and boundary areas, go to scott1965's post of 06-10-2014 09:23 AM, which is Post # 7 in this thread, and click on the photo at the bottom of the post to open the full-size photo of the P10 frame. You must go to this original post. Clicking on the thumbnail picture included in some other post will only open the thumbnail, not the full size picture. Unfortunately I don’t have the equipment to take photos of the vent under 14X magnification. If someone else does, pictures of wet and dry vents would be most helpful.
Out of all this I offer the following suggestions for keeping your P10 functioning correctly:
1. Clean your mask components well in advance of going to bed, so that water has plenty of time to evaporate from the filter before you use it.
2. Try not to run the CPAP warm-up function and then delay going to bed, so as to avoid condensation in the hose and/or mask, which may get into the mask vent.
3. If, in spite of your best efforts, you go to bed and find that your P10 vent is blocked, consider it almost certain that you have moisture trapped in the micro-mesh fabric of the vent. Remove the pillows from the frame. Don’t let your naked eyes fool you into believing that there is are plastic films over the two sides of the vent. Remember that there is no way to blow the moisture out of the vent, you must rely on evaporation. Treat it like a sponge that you cannot squeeze. Gentle heat may help. If you have a hair dryer, gently blow warm air onto the vent and remember that you are only trying to accelerate the evaporation, you are not attempting to blow the water out of the vent, because you can’t.
If your experiences show up something I have missed on this issue, please post the information promptly.
I wish you a very good night.