It’s been proven that humans didn’t actually get most of their fresh air from the rainforest, but actually from millions of these algea in the sea… Which is actually more logical, since trees do the opposite at night, kinda undoing any advantage they made during the day… Hence why it’s said you should never put a decorative small tree or even plants in the bedroom as they can take away oxygen levels in closed rooms at night. It’s even said not to sleep under trees outside at night cause it can cause respiratory problems.
They don’t use enough oxygen over night to negate the effect as they use the carbon to grow. It’s still bad to have a lot of plants in your bedroom, but it doesn’t really matter as long as they are relatively small.
Why shouldn’t you have plants in your bathroom?
They consume oxygen during the night so when you have a lot of them it can cause respiratory problems, that is for the bedroom
An effective HVAC system makes this a non-issue. It isn’t like the air is stagnant, the air handler keeps air moving.
From my experience, european homes don’t have a lot ov ac or ventilation