The Ford Motor Company has developed and open-sourced a DIY kit to supplement the air filtration of a room. This is perfect for FTC meetings during the cold season, where meeting outdoor is unpractical. You may reuse a simple box fan, build a stand with carborad, and will most likely need to buy a MERV-13 or more 20x20x4 air filter. There are relatively easy to find, and cost between $25 to $50. Below are the links for the assembly (here) and the templates for fabricating the cardboard base (here). The original article describing the Ford's Covid effort is included here.

Thanks Ford Motor Company for this wonderful design.

It is now possible to buy high-quality N95 surgical masks. We have gotten several boxes and the one we got strongly appear to be originals (same model as some of our front-line worker parents are receiving from their respective hospitals). While we cannot guarantee that it is (or will remain the case), we have had a good experience with the Halyard Fluidshield Surgical N95 Respirators, ASTM Level 3 sold at Amazon.