Showering for fifteen minutes in my last apartment would push the bathroom CO2 up to 2000ppm, even with the stock weak exhaust fan on, and it would drop slowly

Showering for fifteen minutes in my last apartment would push the bathroom CO2 up to 2000ppm, even with the stock weak exhaust fan on, and it would drop slowly for twelve to fifteen hours but never below 1200ppm so long as someone was home. 750 sounds like luxury :)