> I assumed 5 mins would be enough. Data shows that I need about 25 mins to get CO2 levels down to around 500ppm I also noticed that just cracking a window doe

> I assumed 5 mins would be enough. Data shows that I need about 25 mins to get CO2 levels down to around 500ppm I also noticed that just cracking a window doesn't seem to do much according to the CO2 monitor, except letting the heat escape. The trick is to open multiple windows/doors wide and get some cross ventilation going. This gets CO2 down in only a few minutes. It's called stoßlüften in German.