Stormy condtions ahead: My little electric heater

You might have seen my earlier post here about how I reduced the rain out in Swift LT with a wick:
viewtopic.php?f=1&t=34883&p=298845#p298845

Here is what I think. If you use a (heated) humidifier with Swift LT, and if you do not heat up your bed room at night (as some of us do to save the planet ), and especially if you are routing the small attached hose over your head, and if you are running your cpap at lower pressures like 4-6cm, I predict that more people will experience more rainout as we go into winter in those areas where air does not dry out too much. In the San Francisco Bay Area, for example, the relative humidity is quite high in Winter. Recall that Swift LT was released in the summer, and we have not had our first winter yet. So that is my weather prediction, rain out ahead!

Even with an insulated or even heated regular hose, or using a wick as in my other thread above, some of us may still get some rain out, from the humidity of our own breath condensing in the short tube --- depending on how much condenses . Remember part of our out breath does go back into that short tube, and possibly even further up to the regular cpap tube if the cpap pressure is low, and if we use cflex (or other pressure relief on out breath) modes.

Rainout itself may not be that important or bothersome to some people. But there is another important side effect of this. The condensation taking place in the very very small holes of the out port of Swift LT can actually reduce the intended out port leak sufficiently to alter the effective leak rates over the sleep time at night. If you have the software, you may notice this as a lot of frequent, but small, squiggles in your leak graphs. If one is sensitive to CO2 retention ratio, his/her AHI numbers, and the effectiveness of the cpap therapy may be affected by this. Some of you might also hear high pitched whistling note(s) from the out port from the condensate particles of water vibrating.

So I decided to do an experiment: Electrically heat the very short 12 inch tube which is part of the Swift LT. The results were far better than I had expected! I could get rid of the worst rain out conditions even without a wick or insulating the long cpap hose, or heating the cpap hose, or heating the room, ...

Let me get a few photos, and then I will describe exactly how I did that in the next msg.

OK, the construction is shown in detail at about the 10 th post in this thread below
viewtopic/t36287/Stormy-condtions-ahead ... ml#p315704

not with a heated hose.

There is a lot of moisture in your exhaled breath, if you have a quart or gallon sized Ziplock plastic bag, put it over your mouth and rebreathe in it for a minute or two and watch how much moisture develops on the inside of the bag (lots!).

If you have a lot of mask leak you can easily go though a tank of water a night, I use how much water I use as gauge but I also live in N. Calif near Sacramento and don't use the heat on my humidifier at all, just passover. When the bedroom temp begins to drop, more blankets go on but the humidifier heat remains off even in the dead of winter, air temp gets too cold I use the aussie heated hose with a 9VDC (it comes with a 12VDC supply) and it works great, just takes the chill off the incoming air.

When I got my Swift LT, it was relatively warm. I would only get rain out if I slept for over 9 hours. Once it started getting cold, I started getting it in a shorter time. I was using a 2 on my humidifier. I bought a hose cover and reduced my humidity to 1. It is working better but I am still getting some condensation.

A thought..........

If your CPAP is lower than your head, would you get more condensation in the tube from the CPAP machine than if the machine was level with your head?

Myself, my CPAP machine is about level with my machine. I'd like to place the machine under my bed to make it quieter, but I'm thinking that the machine will have to work harder to push the air up to me and the humidity from the humidifier won't get to me as easy as it would with the machine level with my head.

But like I said, just a thought.

Allen

I've been using the SwiftLT and am no longer routing it over my head. I put as much of the hose as possible under the covers. I sleep on my side, so most of the mask hose is under covers. I haven't had to use my Aussie heated hose yet this year, even though last year I had to use it as soon as the nights got cold. I was heating my house to help prevent rainout as well as using the Aussie hose. This year I am keeping the temp way lower. No rainout so far. Because I don't move around a lot at night, this seems to work for me. YMMV.

RosemaryB wrote:I've been using the SwiftLT and am no longer routing it over my head. I put as much of the hose as possible under the covers. I sleep on my side, so most of the mask hose is under covers. I haven't had to use my Aussie heated hose yet this year, even though last year I had to use it as soon as the nights got cold. I was heating my house to help prevent rainout as well as using the Aussie hose. This year I am keeping the temp way lower. No rainout so far. Because I don't move around a lot at night, this seems to work for me. YMMV.

I've been doing the same thing. Ever since I've been keeping the hose under the blankets, I've virtually eliminated rainout with the swift LT. I absolutely love this mask but was initially worried about the increased rainout...that is until I started keeping it under the blankets.

RosemaryB, freepostg,

Yes, if the hose is not routed over the head the rainout potential is considerably less, probably will have only minor condensation even in winter. The following two main reasons of condensation are eliminated: 1. The open (not under the blanket) over the head route getting cold is where the main condensation occurs. 2. The condensate flowing directly back into the pillows, now will flow into the cpap hose.

I've had my hose under the covers since the beginning. I have never run it over my head. But I am still having rainout issues. When I turn down the humidifier to 1, I tend to wake up during the night because of the dryness. When I turn it to 2, it feels like I am trying to breath in the tropics and that also wakes me up. I ordered one of the reptile heater cords last night. Hopefully, that will help.

Snoredog wrote:not with a heated hose.

There is a lot of moisture in your exhaled breath, if you have a quart or gallon sized Ziplock plastic bag, put it over your mouth and rebreathe in it for a minute or two and watch how much moisture develops on the inside of the bag (lots!).

If you have a lot of mask leak you can easily go though a tank of water a night, I use how much water I use as gauge but I also live in N. Calif near Sacramento and don't use the heat on my humidifier at all, just passover. When the bedroom temp begins to drop, more blankets go on but the humidifier heat remains off even in the dead of winter, air temp gets too cold I use the aussie heated hose with a 9VDC (it comes with a 12VDC supply) and it works great, just takes the chill off the incoming air.

Hi Snoredog, Yes, a heated hose will reduce or eliminate the condensation in the short tube over the head too, if the air can be heated sufficiently in the cpap tube. As you pointed out the moisture from the out breath is a major problem (at least for me); and when the over the head tube gets cooled in low room temps, moisture used to condense there and flow into my nose cushions.

So you are running with under 60% of the normal power with your 9v. My method was to heat only the area, the small tube near the nose, exactly where the condensation was occurring. Hope I will get around to take photos soon.

Hi, I eliminated all rainout in my Swift LT about 4 months ago.
I had my AC blowing nice and kold on me and no rainout with this little home made device.
I am sure those that are good at sewing can make a better one.
This one is made of long (clean new) tube sock. It works wonders!
-Dennis

feeling_better wrote:...
So I decided to do an experiment: Electrically heat the very short 12 inch tube which is part of the Swift LT. The results were far better than I had expected! I could get rid of the worst rain out conditions even without a wick or insulating the long cpap hose, or heating the cpap hose, or heating the room, ...

Let me get a few photos, and then I will describe exactly how I did that in the next msg.

Here is the detail. I used very thin insulated electrical heating wire wound around the small tube in between the normal spiral rib. This photo below shows the overall picture, with some tape at one end anchoring the wire down.


At the other end of the tube, the heater is connected to a small connector at the same place where the tube connects to the cpap tube, so that when Swift LT is to removed from the cpap tube, the wire can be disconnected too. I have used this to disconnect the heater at night, when I thought I might have been feeling a bit too warm. The 12 v dc electricity is supplied thru the cable that is loosely spiraled around the cpap tube, so that it is kept tidy. I use a 12 v dc supply at the other end. The resistance of the wire was chosen to have about 3 watts of heating over the entire stretch of tube. But I can easily adjust the voltage of the dc supply to get different heating levels when needed.


The photo below shows the detail of the wire. The wire I used is thin enough for almost two wire loops to fit in between the original rib. Because the wire is a bit too thick for this, you see the second wrap (looping) of the wire (the left one) is standing out from the first one. I have used about 10 meters (33 feet) of insulated heating wire to cover the entire length of the small connecting tube. I do not electrically heat the main cpap tube


Sorry, this is not something everybody here can easily do. I have no supplier information I can provide. You can use practically use any low voltage supply; select the wire resistance to have the desired power for a given voltage or choose a voltage given whatever wire resistance you have. The hard part was getting thin, flexible, insulated heating wire. I got some from China, but this was not an easy process that I recommend. If anybody here knows sources for small quantity purchase of such insulated heated wire, I am interested in knowing about this. The ones who want to try this will need that help. The wires you might find is usually rather thick, and winding such a wire around the tube as I have done would make that connecting tube a bit too stiff for most peoples taste. I was able to find the very thin and extremely flexible wire, and this does not change the flexing of the original tube at all if I DO NOT WIND THE WIRE TOO TIGHTLY AROUND.

For about the 3 watts of heating that I selected, with a 12v supply, you need a total resistance of about 50 ohms; so the wire should have about 5 ohm/meter resistance.

Australian Heated Hose
Hose cover
And a narrow tube cover as well - I found fleece necessary for both.

O.