I've wondered about using one of my old CPAP machines to supply the air. It seems like they should be able to supply plenty of air.
Mine does! I have tested my Resmed Air Sense 10. The CPAP supply hose fits directly into my Versaflo M300 headgear. Another Convenience is that the CPAP hose will also mate into 3/4 PVC pipe.
First, You have to adjust the settings on your CPAP to maximum air flow and switch off any settings that defeat continuous airflow. You should probably test how long a hose you can use with your unit before you have air velocity loss. I started with the standard 6 foot hose then connected a 9 foot hose(via a small piece of pvc as an interface) to make a 15 foot distance between the m300 and the CPAP. There was a small velocity loss but it was more that sufficient and comfortable. I then added another 6 foot hose and I noticed a slight loss. I I proceeded to add an 8 foot PVC pipe giving a total of 29 feet from the CPAP. At this distance, there was no longer sufficient output.
My original idea was to have the Cpap unit in another room that is a dust proof environment and feed the air supply line though my shop wall. This method was not going to work for my situation. I did not want the Cpap in the same dusty and dirty environment clogging its air intake filter. I also use this equipment at night.
I will solve this problem by building a dust proof box to contain the CPAP. The box will have a vent hose receiving fresh air from outside the shop and this will keep the air supply hose down to 15-18 feet well within the range that I tested.
The advantages for me was obviously cost. Like Emiliano, I found the m300 on EBay or Craig’s list about 6 months after he posted about his find. Thank you
@Emiliano Achaval for sharing.
Additionally, I’m breathing in fresh air/keeping cool and safe for a under 225 dollars total cost. Another advantage is I don’t have a noisy fan blowing in my ear and I am not wearing a battery that will impact my bad back.
The minor drawbacks: I have to carry the CPAP upstairs and reset the configuration for sleep every time I turn. The Online Cpap reporting can not distinguish my sleep vs my Versaflo usage and over reports Sleep apnea events. I have not figured out how to stop Cpap transmission while I’m using the unit for woodturning. Another annoyance is that you have to remember that you are connected to a helmet and a hose when you are moving about in the shop.
All in all, I’m thrilled with it.
Also like to shoutout a thanks to
@AlanZ for all his helpfully advice. As a fellow local club member, I am very fortunate to have access to him and his very talented wife, Lauren.
Before I go, I thought I would mention that I spoke with my anesthesiologist Friend regarding the safety of using an untested air supply. He suggested that I sit in a chair for a while take my pulse and take it again a few minutes after. If I’m not getting the right amount of oxygen, my pulse rate will elevate. He also reiterated to make sure i sterilize/clean the hoses and masks regularly just as I do with Cpap equipment. A point well taken and should be considered for all PAPR systems.
To test, I sat in my easy chair and turned the tv on with Cpap Versaflo combo running for awhile. Ironically, I tuned in on the movie Outbreak with Rene Russo wearing the full bio suit with external air supply.
I watched the remainder of the movie with the Versaflo and Cpap running!