atmosphere; mood; vibe; ambience
Colloquial noun emphasizing the felt atmosphere of a place, person, or situation. Similar to 雰囲気 but with a more sensory, impressionistic nuance.
See also: 雰囲気
このカフェは空気感がいいね。
This café has a nice vibe, doesn't it?
彼女の空気感が好きだ。
I like the atmosphere she gives off.
Compound of 空気 (air, atmosphere) and 感 (feeling, sensation). The exact origin is uncertain, but it likely arose as a colloquial extension of 空気 to emphasize a sensed atmosphere.