[SoftTalker]

They also often don't actually vent externally, they just cycle the air through a mesh (and maybe a carbon) filter and exhaust it back into the room.

[dzhiurgis]

That’s a requirement if you build European energy grade A+++ house (which is a minimum in LT) - can’t just be pulling warm air out and replacing with cold one (idk maybe an HRV can compensate for it).

[throwthrowuknow]

Just breathing your own farts all day

[dzhiurgis]

I think HRV is also mandatory (plenty of old homes are retrofitted too).

[throw0101c]

> They also often don't actually vent externally […]

Some do (I have a relative with such a one).