Does your 420E suck in air through the phone (data) jack? :o

Snoredog · Post by **Snoredog** » Fri Apr 04, 2008 2:10 am

wonder if they make a modular telephone jack filter??

Your 420 will probably be a lot quieter when you replace that filter, in a bind they have those white register filters you put over your HVAC at Lowes or Home Depot, they are polyester, you could cut up one of those a put down a single layer then the block foam, it would keep the dust out.

alsarnac · Post by **alsarnac** » Fri Apr 04, 2008 2:26 am

[quote="DreamStalker"]So what you all have discovered is that the 420e has a mechanical exhalation relief via the phone jack?

tangents · Post by **tangents** » Fri Apr 04, 2008 6:35 am

I'm a little confused.

Last night, I put a piece of clear packing tape over the phone jack. I was ecstatic that there was no whistle noise last night! But do I understand correctly that I may now be interrupting air flow meant to cool the electronics? That would suck (and blow).

Thanks for all the great discussion,
Cathy

ozij · Post by **ozij** » Fri Apr 04, 2008 8:12 am

Good question.
Which filters are you using, Cathy?

O.

tangents · Post by **tangents** » Fri Apr 04, 2008 8:57 am

I use CPAP.COM white filters, and the grey filter from a Respironics DS100.

ozij · Post by **ozij** » Fri Apr 04, 2008 9:13 am

What happens if you take the disposable filter out?
Do you have any original PB filter to try?
(Why a Respironics, by the way?)

DME Daddy wrote:This machine is designed to be cooled by air flows being generated by the fan. These pass through a little hole and then flow out of the cpap housing, taking heat with them. I have never paid much attention to how much air is moving through the machine and out the RJ-11 jack. You guys ask the hardest cpap questions in the world!

.

Some more questions:

Which fan and which hole? Do you mean there's a hole in the RJ11 jack? Do you mean the RJ11 is used for cooling?

Can anyone explain what happens when the machine is using thicker filter than it is meant to use - and why that causes it to suck air in through the RJ11 jack? It happens immediately, and even on idle pressure. It may be the software, instructing the fan to blow harder in order to achieve the prescribed pressure.

Another question: What is going on in the machine when the filters are too thick, and the RJ11 is plugged (or ever taped)?

O.

DME Daddy · Post by **DME Daddy** » Fri Apr 04, 2008 10:39 am

Here is the basic situation. There is only one fan in the machine. It sucks air in through the main filter and blows it out the hose connector and ultimately to the patient. The design of this machine uses a tiny opening in this circuit on the pressurized side to release a flow of air inside the cpap's main housing. The air flows through the machine and exits the housing where ever it can. It take heat out of the machine in that process. This keeps things cool inside the cpap thus promoting long life.

DME Daddy · Post by **DME Daddy** » Fri Apr 04, 2008 10:42 am

If the filter is blocked, the motor works hard and may overheat and fail. Too many filters has the same effect. Follow the manufacturer's recommendations.

tangents · Post by **tangents** » Fri Apr 04, 2008 11:29 am

What happens if you take the disposable filter out?

The unit still whistles, if that's what you're asking. I didn't realize that the filters had fallen out for the last week or two - and it's been whistling.

Do you have any original PB filter to try?

I honestly don't know. I don't think I got many with my machine (2 maybe?) Where do you get official PB filters, anyway? From a DME?

(Why a Respironics, by the way?)

LOL! I started my therapy with the DS100. So I borrowed the washable grey filter and put it on the outside of the white one. Now I use the DS100 to blow dry my hose/mask/humidifier every morning! For some reason, this entertains me every single morning.

ozij · Post by **ozij** » Mon Apr 14, 2008 5:21 am

Bumping this up for dsm -
You were on that car trip when I made the discovery - and I wonder if you have any input on the subject.

Thaks,
O.

echo · Post by **echo** » Mon Apr 14, 2008 5:43 am

My 420E also whistles, but it has since the day I got it, which was in August last year, from cpap.com.
So I tried the kleenex experiment:

- Fine filter + cpap thick white foam filter = kleenex gets sucked in
- Fine filter only = kleenex gets sucked in
- Original P&B porous yellow'ish foam filter = kleenex gets sucked in
- NO filters at all = kleenex gets sucked in

The 420E wasn't connected to any hose or mask, just blowing in the wind.. so the kleenex was getting sucked in both a 8cm pressure and at the "ln 1" pressure (since i wasn't connected to it at the time).

I didn't try to see what happens to the kleenex if i breath through it.

In summary, mine IS taking in air through the jack, regardless of pressure or whether any filters are in place.

I expect that shouldn't be a problem, assuming that the jack intake isn't connected to the air compressor itself. Maybe DME daddy can confirm?
(although that wouldn't explain the "exhale relief" that Ozij & RG were experiencing...)

echo · Post by **echo** » Mon Apr 14, 2008 5:46 am

and uh stupid question: I thought fine filters were within the recommendation guidelines for P&B... ?
However, for the foam filters, should we be using the more porous ones (the originals) or are the thick white foam filters also ok??
Me confused now...

Snoredog · Post by **Snoredog** » Mon Apr 14, 2008 9:05 am

echo wrote:My 420E also whistles, but it has since the day I got it, which was in August last year, from cpap.com.
So I tried the kleenex experiment:

- Fine filter + cpap thick white foam filter = kleenex gets sucked in
- Fine filter only = kleenex gets sucked in
- Original P&B porous yellow'ish foam filter = kleenex gets sucked in
- NO filters at all = kleenex gets sucked in

The 420E wasn't connected to any hose or mask, just blowing in the wind.. so the kleenex was getting sucked in both a 8cm pressure and at the "ln 1" pressure (since i wasn't connected to it at the time).

I didn't try to see what happens to the kleenex if i breath through it.

In summary, mine IS taking in air through the jack, regardless of pressure or whether any filters are in place.

I expect that shouldn't be a problem, assuming that the jack intake isn't connected to the air compressor itself. Maybe DME daddy can confirm?
(although that wouldn't explain the "exhale relief" that Ozij & RG were experiencing...)

You have to be careful what filters you install and use. I know on some of my purchases of 420's cpap.com thew in some "fine filters", they didn't appear to be PB's, while it was real nice of them to toss those in for free, fact is they restrict air flow, the PB-420 only comes with the gray foam filter, when it doubt that is ALL you should use, if it is dirty, take it to a sink and wash it out then dry it really well in a towel before reinstalling.

tangents · Post by **tangents** » Mon Apr 14, 2008 9:11 am

What's your reasoning, Snoredog? Even if the white filter restricts the flow, doesn't the software adjust for that on the output? I'm not happy with just the filter that came with the 420E, it's way too porous. My unit has never felt warm in the morning, so I don't think overheating is an issue.

Thanks for everyone's inputs on this thread.

Cathy

Snoredog · Post by **Snoredog** » Mon Apr 14, 2008 9:12 am

[quote="DME Daddy"]Here is the basic situation. There is only one fan in the machine. It sucks air in through the main filter and blows it out the hose connector and ultimately to the patient. The design of this machine uses a tiny opening in this circuit on the pressurized side to release a flow of air inside the cpap's main housing. The air flows through the machine and exits the housing where ever it can. It take heat out of the machine in that process. This keeps things cool inside the cpap thus promoting long life.