Gaining extra humidity in Respironics System One CPAP machin

For those who need extra humidity, the regular PR heated humidifier sometimes cannot deliver either enough humidity or long enough humidity. Setting the humidifier to 5 may not be sufficient and, given local circumstances, may run the humidifier chamber dry before morning.

So, the solution is to incorporate an external humidifier in the breathing circuit to enhance the humidity and duration.
Fisher-Paykel makes an external humidifier (HC 150) that can be used with any CPAP machine that doesn’t have one built-in. It consist of a chamber and a heater element to provide warm and humid air to the patient. The temperature is adjustable for off to quite warm.

When used alone, this is usually sufficient.

However, when used in conjunction with a built-in humidifier, so special considerations apply.

Because the hose is a standard CPAP hose, it cannot be used between the system humidifier and a heated hose. There is no electrical connection. It cannot be used as a passive pass over humidifier because the temperature will drop and cause extreme rainout by the time the air gets to the mask.

Those features can be overcome and the HC 150 used successfully as an external source of additional humidified air.

First, the heating function must be turned on so that the heated air from the CPAP machine is not cooled and the effect lost.

Second, the hoses both for the HC 150 and the regular CPAP hose must be insulated to prevent temperature drop and subsequent rainout.

A little experimentation will be required to adjust your CPAP humidifier settings to work properly for you. Generally you will set your current value a little lower. This gains additional humidifier time before the chamber runs dry. The HC 150 temperature setting will be set fairly low (not off) otherwise the resulting humidity will be just like in a sauna. A combination of these two settings will get you more than 9 hours of full humidity at whatever level you need.

I use a fleece material from the fabric store to provide a double wrap around the HC 150 connector hose. The chamber doesn’t need to be insulated as it is already heated. A half hour before connecting up, I turn on the Respironics pre-heat function and turn on the heater for the HC 150. That way, the air is already cozy when bedtime comes.

BTW, this discussion applies to other manufacturers as well providing their machine can have an external device spliced into the breathing circuit.

Since the machine depends on room air would running a room humidifier be sufficient to provide enough extra humidity that the tank won't run dry? This time of year, I don't use much water from the tank, but this winter with the very cold weather we had here in the Midwest, my tank always ran dry. I'm trying to think of way to fix that before next winter.

Yes, a room humidifier can help. Do not get one that sprays a fine mist into the air since that gets extremely fine mineral particles in the air as the water drop evaporate. You will notice the fine, white dust everywhere from this type of machine.
I have tried the old-fashioned heated water types as well as the newer evaporative kind that uses a filter to add water to the air.

The heated type are much more expensive to run but are cheaper to purchase.
The evaporative type have filters in them that need to be replaced from time to time, my replacement cycle was 30 days.

If you go that route, then you will need to close the room so that the humidified air doesn't disperse through your house.
It does help since the air entering the CPAP machine starts out with a higher relative humidity.

Last year I was glad I heard about Phillips Respironics S1's CLASSIC MODE which runs the humidifier at much higher humidity levels (I've got a Hybernite hose for the wintertime, so no problem with rainout).

Here’s how to do it with PRs: I used the setup clinician's menu on my PR S1, went to System One Humidifier line, clicked the thumb wheel and turned the wheel until the LCD display said 'off' (it requires a leap of faith). Immediately up popped the 'classic mode menu' on the line below - I then selected C3, which is the middle range. Push the button wheel to enter your changes, then rotate the knob to 'exit'.

Just be sure to totally fill up your tank at bedtime and hopefully it will last all night, if not, simply keep a small water bottle full of distilled water near your bedside and top up the tank as necessary. This method uses LOTS of water. It's also great for FFM users who tend to mouth-breathe. You can enter Classic Mode into the search engine at the top of each page... that will produce 37 pages of write-ups and tips. Sorry ResMed owners - this is just for PR users, however JDS's idea will apply to ResMed machines, I assume.

JDS74 wrote:Yes, a room humidifier can help. Do not get one that sprays a fine mist into the air since that gets extremely fine mineral particles in the air as the water drop evaporate. You will notice the fine, white dust everywhere from this type of machine.

Wouldn't using distilled water in the humidifier prevent this?

Drowsy dancer,
Yep, using distilled water in one of the fine mist units will work just fine with no fine dust.
However, because your are humidifying the entire room, the water used will not be the 11 ounces or so in the CPAP humidifier chamber but will be more like 1/2 to a full gallon each nite. My cost per gallon of actual distilled water is about $1.25 so the cost increase as compared to tap water would be more than $.60 per day.

Some folks have their own distillers and report that their cost per gallon is quite low. That would be another way to go.