False-ceiling construction and method for the flow of air in connection with a false-ceiling construction

False-ceiling construction (10), which is intended in particular for institutional kitchens and which false-ceiling construction is composed of modular units, which comprise at least an intake air unit (11) and an exhaust air unit (18) and, in the area between them, a false-ceiling plate (25), and which false-ceiling construction is formed underneath a ceiling (C) proper in a room, a free space (E) remaining between the false-ceiling construction (10) and the ceiling (C) proper of the room, which false-ceiling construction (10) comprises an intake air duct (12) for the flow (L.sub.1) of fresh air to be passed into the room, said duct (12) being connected to a box (14) which defines the intake air chamber in the intake air unit, and from which intake air chamber (13) in the intake air unit (11) at least one flow opening (15, 16) is opened for the flow of fresh air entering into the room, and that the false-ceiling construction comprises an exhaust air unit (18), which comprises a box-shaped frame (23), which defines an exhaust air chamber (19) in its interior, an opening for the exhaust air flow (L.sub.2) being opened from the room space into the exhaust air chamber (19), which opening includes fat filters (21) in its connection, and which exhaust air chamber (19) is fitted to be placed in the false-ceiling construction above the food-making means placed in the room space, and that the false-ceiling construction (10) comprises the false-ceiling plate (25) to be installed in a modular way, at least one false-ceiling plate (25) being fitted in the area between the intake air unit (11) and the exhaust air unit (18), and that the false-ceiling construction is supported by means of a support construction (27) on the ceiling (C) proper of the room space, characterized in that the false-ceiling construction (10) includes a first flow opening (15) structured and arranged to pass fresh air therethrough from the intake air chamber (13) in the intake air unit (11) to the room space (H), such that a trap-air jet (L.sub.1a) flows parallel to the plane (T) of the false-ceiling plate 25 or as slightly inclined in relation to said plane towards the exhaust air opening (20), placed on the exhaust air chamber (19), for the exhaust air flow (L.sub.2), whereby, by means of the trap-air jet (L.sub.1a), contaminated air and/or excessive heat or excessive humidity (L.sub.3) rising from the sources of impurities in the room space is attracted towards the exhaust air unit (18) and removed from the room space (H), and in this way gathering of impurities and/or excessive heat and/or excessive humidity in the area between the intake air unit (11) and the exhaust air unit (18) at the proximity of the false-ceiling plate (25) of the false-ceiling construction is prevented, the box (14), which defines said intake air chamber, is provided with a second flow opening (16) at its bottom for guiding an air flow (L.sub.1b) directly downwards, said second flow opening (16) including a perforated plate (17) for the purpose of guiding the air flow (L.sub.1b) at a low velocity into a working zone of personnel working in the kitchen, whereby a detrimental sensation of draft in the working zone is avoided.