@alisynthesis@io.waxandleather.com 3M 7500 series respirator with the right filters attached is inconvenient but effective. The 2297 seems to work but they have a whole guide that has details. I use commercial air filter units indoors, no real opinions about the better option there but I am curious how to build something better than what I've got (I specifically don't want all the fancy touch controls, WiFi connectivity, etc, that they have).