AIR CONDITIONER FOR BUILDING

PROBLEM TO BE SOLVED: To shorten a route of a horizontal piping duct by forming a duct opening communicating with a duct main pipe at a lower floor of a door in the state that the door is closed, providing a piping duct communicating with the duct opening in the door, and providing an air outlet at an upper part of the door. SOLUTION: Since a communication hole formed at a shield plate of an opening/closing mechanism provided under a floor 21 of a habitable room 2 coincides with a horizontal piping duct 5A of an air outlet side at a lower surface and coincides with a duct opening 25A of the air outlet side at an upper surface at the tie of closing a door 24, the opening 25A of the outlet side becomes an opened state. Accordingly, the air fed from a duct 4A of the outlet side is supplied to an air outlet 42 and then into the room 2 via the duct 5A and a piping duct 44A. Further, a duct opening 25B of the outlet side also becomes an opened state. Then, the air in the room 2 is sucked from a suction port 43, and fed into an air conditioner body through the duct 5B and a duct 4B of the suction port side.