palautusilmalähteet
Palautusilmalähteet, often translated as return air inlets or exhaust air grilles in English, are components of a building's ventilation system. Their primary function is to collect indoor air that has been circulated through the building and direct it back to the central air handling unit. This returned air is then typically filtered and mixed with fresh outdoor air before being re-conditioned and distributed back into the occupied spaces.
These inlets are strategically placed throughout a building, commonly in rooms, corridors, and common areas. They
In some systems, particularly those with heat recovery, the air drawn through the palautusilmalähteet is used