Seeing North Americans post about fan-filter-boxes built with box fans and HVAC filters and am reminded of someone back on Twitter (I think it was Amanda Hu) turning their entire home into a fan-filter-box by putting fans into windows on one side of the house and then putting the filters in windows on the other side of the house. Remember: you want the air to be blowing outward and being pulled inwards through the filters.
#FanFilterBox #CorsiRosenthalBox #CRBox #IndoorAirQuality