A Coanda effect diffuser . . .
42KY is a single-slit peripheral air outlet which has a slim opening and specific internal profile to increase the initial speed of the air leaving the diffuser.
The high speed of the air stream induces a negative pressure which “sticks” it to the ceiling (thereby avoiding direct air flow onto the occupants) and an induction phenomenon which attracts the ambient air and re-injects it into the stream of air.
The mixing rate and the range and coverage of the air stream are improved, reducing the thermal phenomena (residual air speed, asymmetric temperatures, radiation from walls, and so on) that cause discomfort in occupied spaces.