PR Dreamstation Modification Question

[KenSleep]

I am reading, and viewing youtube videos of people modifying their Dreamstatiions by removing the black "sound abatement foam".
I understand that this procedure is not recommended by any party and will obviously void any warranties.

If the present black foam is removed, and the entry cuts sealed either by duct tape or glued plastic plate, I presume that there is an incease in the 
"noise" that the cpap machine makes during operation. Is this noise increase significant? 

And, has anyone discovered a replacement material that is safe and effective?

Thank you for any advice.

[LindanHotAir]

The sound increase is minimal. If you use plastic plugs to close the openings and they are not trimmed short, they can create turbulence and mess up flow sensor readings.They can also whistle. Smooth seals are quieter. It is important that all openings are closed off and all port seal grommets are replaced.  A lot of the videos that leave openings and break off the temperature/humidity sensor tube are wrong and the machine will no longer function properly.

[KenSleep]

The sound increase is minimal. If you use plastic plugs to close the openings and they are not trimmed short, they can create turbulence and mess up flow sensor readings.They can also whistle. Smooth seals are quieter. It is important that all openings are closed off and all port seal grommets are replaced.  A lot of the videos that leave openings and break off the temperature/humidity sensor tube are wrong and the machine will no longer function properly.

Thank you very much for your advice. I fully understand the need to avoid creating any obstructions to the air flow itself. As well as ensuring
that there are no openings. But I do not understand why you are recommeding replacing the grommets, unless one damages them in the take-apart
process. The sensor tube caution is duly noted. 
I do take apart and repair latop PCs so I am pretty used to working carefully with small sensitive parts.
Again, many thanks.

[Neelix]

It may also depend on your pressure. I just got a response to a comment on one of Nick's youtube videos saying that their BiPAP machine which they use on high pressure was significantly louder after removing the foam, though they did not say what method they used to remove it.

It did make me wonder though at the practicality of building an external foam shell (possibly inside a fabric cover and with a gap around the air intake so as not to block the flow) that you could put on top of the machine like a tea-cosy after turning it on to duplicate the sound abatement effect without actually having the foam being in the airpath...

-Neelix

[LindanHotAir]

The grommets are normally not damaged, but they can come out attached to the sensor tubes. There is a double grommet that straddles the motor wires. Just make sure all the grommet seals are back in place when you reassemble the machine. There is one at the output port, a pair at the flow sensor restriction, and one at the top of the temperature/humidity tube.

[RayBee]

Take more pictures than you think you will need with your smartphone during disassembly. It helps a lot. That’s what I did. It helped prevent growing bald spots from scratching my head during reassembly.

[KenSleep]

I have little doubt that the sound level is directly linked to the level of air pressure. As I am running my DS at 6-7 levels I doubt that I will have a sound issue. I say this because I pushed the pressure up to 10 just to see and the sound comming out of the nasal pillow was very considerable.

Your idea of an exterior sound barrier makes sense if in fact, an increased sound level becomes a problem. That was behind my earlier question as to whether anyone was aware of a possible replacement "foam", medically safe that could be used.

I haven't seen all of the PR DS foam removal videos out there, but I do have both a drill with wide bit, as well as a dremel with cutting wheel. So I am ready to do an "invasive" removal at any time. But I did read on one of those videos where someone posted that they used a Heatgun to soften the glue, and an exacto knife to cut/separate the "lid" on the entire plastic casing. Which of course would make foam removal easy, although the casing would have to be sealed again. I have no heatgun, but it did make me wonder if the plastic casing were to be placed in a large pot of boiling water, that might soften the adhesive allowing for removing the "lid". If so, it would be easy to remove the foam and glue the kid back on. 
And- if there were a suitable replacement foam, it cold even be inserted.
I have in the past solved "glued on" parts problems by this boiling water method. Just a thought...

[remseeker]

KenSleep - Have you checked the "The DreamStation Foam Removal Thread" at 

http://www.apneaboard.com/forums/Thread-...val-Thread?

In this thread, I found rocketrobo's method of using food grade plugs for foam removal to work very well, with no detected changes in the operation of my DreamStation BiPAP autoSV, using my 6/4 pressure settings.  I didn't think to trim the plugs to avoid possible turbulence effects, but luckily didn't seem to have turbulence problems anyway.

As I mentioned in post #94 of this thread, using a step bit proposed by Raybee resulted in a very clean drilled hole and a snug, seemingly air-tight fit at nominal pressures.

Depending on the humidity conditions, I think that some sort of ESD precautions should be used to avoid damaging the main circuit board.

The foam I removed seemed to be in good shape.  I never pushed ozone through my DS, although I use the Sleep8 cleaning method of an ozone bag treatment for my tubing and water reservoir.

[KenSleep]

I had not seen that thread. I will go through it promptly.
Thank you very much.