I, actually run a 6 inch snorkel out from the basement with fine metal mesh clamped onto the intake. Reduces to 4 inch through the wall, then through a filter

I, actually run a 6 inch snorkel out from the basement with fine metal mesh clamped onto the intake. Reduces to 4 inch through the wall, then through a filter box, then through a 200cfm fan. You want 15cfm per person in the building to flush enough CO2. After the two filters, a 200 cfm fan will not be pulling what it’s rated for. You can either use a bathroom exhaust fan in reverse, or you can get quiet enough fans from “indoor gardening companies”. The dehumidifier is standard, nothing fancy.