[CPAP] AirSense Blower Failure

[mjrPdqkLguUgGLE]

I have had three AirSense (S10) APAP units.  The second two were warranty replacements.  I will describe the failure mode, and am wondering if anyone else experienced the same thing.

The failures were all catastrophic making the machine unusable.  Suddenly, a high pitch noise started.  The noise was constant in amplitude.  Each failure has a different level of noise.  One was as loud as a car horn.  The other two were not as loud but obnoxious anyway.

I think the failure was a bearing in the blower unit.  One reason is that I have had computer cooling fans develop a damaged ball bearing and make high-pitched sound.  So there is an analogy with my APAP experience.  Another reason is that I guess that ResMed used very quiet ball bearings.  I think these are more susceptible to failure. The puzzling thing is that three units arriving about eight months apart had the same failure.  This would suggest that this kind of fire is very common.  I think it cannot be, or I would have heard about it by now.

Could my particular environment be the problem?

II had more than three humidifier chamber leaks, where the whole chamber emptied overnight.  However, I am not sure how such leaks could damage the ball bearings.

In addition, the APAP units used air output from a HEPA filter.  The filters that ResMed provides never got dirty.  In other words, the input air was very clean, so that dirt would not have been a cause.

Has anyone experienced a similar failure?

[sheepless]

nope. that's truly a string of bad luck! I suppose it's possible to get 3 bad machines, particularly if they were all manufactured at the place or the in the same lot. still it's quite a coincidence, leading one to suspect the environment. heat and dust primarily, I'd think. hopefully the seller is replacing them for you.

[Sleepster]

In addition, the APAP units used air output from a HEPA filter.

That could be your problem. The HEPA filter is restricting air flow to the CPAP machine.

I've had mine for a few years now and it's just as quiet as it ever was.

I have a HEPA filter in my bedroom, but it's not connected to my CPAP machine. It just cleans the air in the room.

The filters in the A10 (and in its predecessor, the S9) never got visibly dirty for me, either. I think because we never open the windows! We either have the air conditioner or the furnace on. I'm sure they get contaminated with dust, though.

Note how porous these filters are. This may be a clue. The engineers may have had to design things this way so that the blower motor wouldn't be starved for air.

[mjrPdqkLguUgGLE]

In addition, the APAP units used air output from a HEPA filter.

That could be your problem. The HEPA filter is restricting air flow to the CPAP machine.

I've had mine for a few years now and it's just as quiet as it ever was.

I have a HEPA filter in my bedroom, but it's not connected to my CPAP machine. It just cleans the air in the room.

The filters in the A10 (and in its predecessor, the S9) never got visibly dirty for me, either. I think because we never open the windows! We either have the air conditioner or the furnace on. I'm sure they get contaminated with dust, though.

Note how porous these filters are. This may be a clue. The engineers may have had to design things this way so that the blower motor wouldn't be starved for air.

---

Hi,

Thank you for your ingenious explanation. Some additional features of my set up, suggest that the cause is different.

The HEPA filter creates a stream of filtered air traveling upwards in the open room before it gets to the air intake for the APAP machine. The air sense is several inches above this airstream. So it is uses only part of the airstream.

The APAP motor is not starved of air, because the input airstream is not confined (as much air as needed is available). In addition, the air is moving very slowly (the filter is on the lowest setting). Also, the filters in the HEPA filter are changed regularly, so they are always clean enough. This means the speed of the air stream never slows down.

Note also that the same HEPA filter configuration was previously used for six years with an ResMed S9 APAP. This older APAP machine never failed. This is an argument that the environment is not a factor.

This raises the question of whether the humidifier water leaks could have caused electronic damage in the AirSense, that in turn caused some damage to the lower control circuit, which in turn caused some altered behavior in the fan, the degraded one or more ball bearings over time. I do not know what mechanism could explain this. However, note that the last failure occurred only three weeks after a leak occurred.

Steve

[StevesSp]

I have used HEPA filters on my S9 Elite for many years, with no problems.