Maximum hose length

I have been using an 8 ft hose on my auto BiPAP machine. I toss and turn a lot and the extra length reduces pulling the machine off my nightstand. I get 6 ft hoses for free and would like to use them. An in-line coupler would cascade two 6 ft hoses. Since the sensors for auto ipap/epap are in the machine, is there a maximum length that will allow the machine to sense what is happening at the mask? Does some manufacturer sell a 2 ft extension?

There are people using 2 of the 6 ft hoses without any apparent issues with 12 ft.
Manufacturer's do make a 10 ft hose that is readily available so I would assume that 10 foot isn't a problem.
I can't say for sure about 12 ft though...might make yourself a manometer to check the pressure you are getting to see if it corresponds with what you are supposed to get.

They do make 2 foot hose extensions though.
https://www.cpap.com/cpap-hose/cpap-hose-short.php

Before anyone asks...heated hoses are pretty much 6 ft only...if you want to use a heated hose then you would have to piggy back a non heated extension to the end of the heated hose. You would lose some of the heated hose benefit but it still might be enough to get the job done.

I've been using the 8' hose for years. I need the 2' so I'll be getting the 10'.

Sheriff

wlenz wrote:I have been using an 8 ft hose on my auto BiPAP machine. I toss and turn a lot and the extra length reduces pulling the machine off my nightstand. I get 6 ft hoses for free and would like to use them. An in-line coupler would cascade two 6 ft hoses. Since the sensors for auto ipap/epap are in the machine, is there a maximum length that will allow the machine to sense what is happening at the mask? Does some manufacturer sell a 2 ft extension?

Over the years, there have been discussions about this subject. I remember somebody saying that they even connected two 10' hoses with (virtually) no pressure loss with fixed pressure. However, the cautionary points were about when using ranges of pressures and the possible delay in the machine sensors being able to function properly. Straight pressure presents virtually no problems, but with pressure ranges there may be some, depending how long the distance is.

Found a couple of those old threads:
I believe the later one also references the earlier ones.
The forum member "dsm" did a variety of tests, too.

viewtopic.php?f=1&t=21043&

viewtopic.php?f=1&t=37508&


Den

.

I am not going to mention my maximum hose length here.......it's just too personal

wlenz wrote:I have been using an 8 ft hose on my auto BiPAP machine. I toss and turn a lot and the extra length reduces pulling the machine off my nightstand. I get 6 ft hoses for free and would like to use them. An in-line coupler would cascade two 6 ft hoses. Since the sensors for auto ipap/epap are in the machine, is there a maximum length that will allow the machine to sense what is happening at the mask? Does some manufacturer sell a 2 ft extension?

the resmed bilevel machines have a setting for a 10 foot hose. (which I use on mine) this allows better pressure delivery, since the resistance of the hose will have some affect on the pressures at the mask....

Just as a point of reference...

I ran this question by a process engineer. Assuming 50 feet of 22 mm diameter smooth bore hose and a pressure of 20 cm H2O at a constant flow of 50 liters per minute the "rough" calculation indicates that you would have a little less than 0.05 cm H2O difference at the output.

That means that if you set the pressure on your machine to 20 cm H2O and use a 50 foot hose (22 mm diameter) you would only end up with about 19.95 cm H2O at the mask.

The manufacturers set a 10 ft maximum hose length for a reason, adding more than that degrades the machines ability to detect the need for pressure changes, and the collecting of reliable data. Jim

HoseCrusher wrote:Just as a point of reference...

I ran this question by a process engineer. Assuming 50 feet of 22 mm diameter smooth bore hose and a pressure of 20 cm H2O at a constant flow of 50 liters per minute the "rough" calculation indicates that you would have a little less than 0.05 cm H2O difference at the output.

That means that if you set the pressure on your machine to 20 cm H2O and use a 50 foot hose (22 mm diameter) you would only end up with about 19.95 cm H2O at the mask.

And, if you look in the machine manuals, the pressure specifications typically show an accuracy of +/- 0.5 to +/- 1.0 depending on the pressure settings.


Den

.

HoseCrusher wrote:Just as a point of reference...

I ran this question by a process engineer. Assuming 50 feet of 22 mm diameter smooth bore hose and a pressure of 20 cm H2O at a constant flow of 50 liters per minute the "rough" calculation indicates that you would have a little less than 0.05 cm H2O difference at the output.

That means that if you set the pressure on your machine to 20 cm H2O and use a 50 foot hose (22 mm diameter) you would only end up with about 19.95 cm H2O at the mask.

the tricky bits, however, come when you've got varying flow, as you do when you're breathing, that causes more or less pressure drop over the length of the hose.

wlenz wrote:I have been using an 8 ft hose on my auto BiPAP machine. I toss and turn a lot and the extra length reduces pulling the machine off my nightstand. I get 6 ft hoses for free and would like to use them. An in-line coupler would cascade two 6 ft hoses. Since the sensors for auto ipap/epap are in the machine, is there a maximum length that will allow the machine to sense what is happening at the mask? Does some manufacturer sell a 2 ft extension?

Have you tried a hose hanger to isolate your movement from the machine/
I use a hose hanger and also tie my hose to my four poster bed and cannot pull the machine at all.

Thanks for all the great replies. I will only use 8' hose, it is anchored to my bed with a velcro strap, and I will monitor the data frequently.
Again, thanks

TangledHose wrote:I am not going to mention my maximum hose length here.......it's just too personal

... feeling inadequate 'cause I've just got an "average" hose

Could I be suffering from "hose envy"?