[Equipment] Data Based Cleaning Schedule

[diamaunt]

you'd have to be exhaling incredibly fast, and hard, and with superhuman volume to get anything back down that hose and into the humidifier.

I accept the challenge. It's hoses at 10 paces at dawn!

Actually I checked my negative flow and it records about 40 LPM.
Looking at a spread sheet where I did a curve fit to intentional mask leakage v pressure, at my pressure, the mask outflow exceeds 40. So, indeed I'd have a tough time pushing air back up the hose.

also, if .68 liters of your breath went back down the tube (appx volume of a 22m 6' hose) then you'd be rebreathing that on your next inhale.

can I bring my 3 meter hose to this fight?

[andersonsta]

Look at the air flow data. It's swings positive and negative. The sensor is located upstream of the humidifier.
Does this not indicate that when we exhale, we expel air back up the hose, through the humidifier?

(Unless the zero flow reference is relative; and we only reduce the outflow of the machine...)

you're not taking the mask vents into consideration in your theory.

yes, the "zero" flow is zero relative to respiration, not zero absolute.

you'd have to be exhaling incredibly fast, and hard, and with superhuman volume to get anything back down that hose and into the humidifier.

The design on the Resmed will probably prevent it, but I regularly had to check the filter on my Respironics because a moderate cough would blow the filter out of it. Of course, that does not mean the air I exhaled actually reached the humidifier, just that the airflow was reversed.

[diamaunt]

good point, and another plus (in my feeble mind) for the resmed design

[zonk]

Okay, I,m going skip the science class this morning and head straight to the subject matter

I use tap water, boiled and cooled
I've not seen any deposit in the tank at all

Fisher and Paykel say:
the use of normal tap water will not harm you but may cause the chamber to deterioate at a rate faster than expected

[Sleepster]

So, indeed I'd have a tough time pushing air back up the hose.

Right. The purpose of the mask vent is to keep the hose purged of exhaled air.

[archangle]

Actually I checked my negative flow and it records about 40 LPM.
Looking at a spread sheet where I did a curve fit to intentional mask leakage v pressure, at my pressure, the mask outflow exceeds 40. So, indeed I'd have a tough time pushing air back up the hose.

On cold days, I can often see condensation form on the inside of the hose connection as I exhale into my ComfortGel nasal mask. This is past the air vent, so some air is going up the hose. Getting the air all the way back to the tank would be quite a feat, though.

My tidal volume is around a liter, and my standard hose seems to hold around a liter of water, so the air could almost reach the tank if I exhaled rapidly.

I suspect the air doesn't generally make it that far, though.

[Sleepster]

Cleaning the tank daily seems stupid to me.

I rinse mine out and let it air dry every morning. I've been doing this for well over a year and have never had any problems. I'll wash it once or twice a month.

Manufacturers tend to err on the side of "wash more often" because it protects them against law suits.

This Wiki article addresses the type of water to use, but it also contains some references to what has happened in rare cases where the water is contaminated.

http://www.apneaboard.com/wiki/index.php...fier_water

I'm not aware of any studies that document the washing frequency. Probably because there are just too many variables due to different levels of water purity and ambient air conditions.

For example, I live a home with central air conditioning and I have a water softener and sediment filter. I just use my tap water.

[justMongo]

Zonk:
I often use filtered tap water. It may result in some mineral deposits as it evaporates from the tank.
Seems to wipe away with 5% white vinegar. Unless you'd like to ship me some Australian Riesling!
I think for the Resmed, especially with the tank with the aluminum lower half, too pure water may eat away at the metal.
BTW -- are you the person who uses the stainless steel bottom with the upper from a non-diswaher safe tank?

Another point I left out was that 40 LPM is my peak exhalation rate; but it is short duration. Integrated over time it is much smaller.

diamaunt:
Of course you may bring your 3 meter (length) hose. I'll bring my 3 meter diameter hose!

My Hose:

[diamaunt]

diamaunt:
Of course you may bring your 3 meter (length) hose. I'll bring my 3 meter diameter hose!

all right, this size war is getting out of hand!

[zonk]

Zonk:
I often use filtered tap water. It may result in some mineral deposits as it evaporates from the tank.
Seems to wipe away with 5% white vinegar. Unless you'd like to ship me some Australian Riesling!
I think for the Resmed, especially with the tank with the aluminum lower half, too pure water may eat away at the metal.
BTW -- are you the person who uses the stainless steel bottom with the upper from a non-diswaher safe tank?

Yes, you've been paying attention, you can go to the top of the class

As for the Riesling, make sure you drink the wine, we don,t want to pour such a good drop down the drain