I’ve had a couple versions of this PAPR, mostly 3D printed. The first used a smaller blower with an AC mains power supply and two 3M bayonet filters. Those filters are a guaranteed performance but do have lower capacity than commercial PAPRs (though the 3M Powerflow uses a single face-mounted cartridge and blower).
I recently revised it to use a larger fan and a Milwaukee M12 battery, and kept the 3M bayonet filters.
Now, instead of using someone else’s battery-holder design, I made a derivative of it. As filters, this revision uses two Roomba HEPA filters. That gives much more flow and hopefully filter life. If the filters are legitimate HEPA material, the filtering would be similar to the 3M filters. Hard to know but I’ll know more after I test a bit. I have an outlet adapter in my welding hood, which also has a leather cape, and it sure makes it nicer under the hood.
I recently revised it to use a larger fan and a Milwaukee M12 battery, and kept the 3M bayonet filters.
Now, instead of using someone else’s battery-holder design, I made a derivative of it. As filters, this revision uses two Roomba HEPA filters. That gives much more flow and hopefully filter life. If the filters are legitimate HEPA material, the filtering would be similar to the 3M filters. Hard to know but I’ll know more after I test a bit. I have an outlet adapter in my welding hood, which also has a leather cape, and it sure makes it nicer under the hood.