Abstract: An indoor air-conditioner unit comprises an air duct, an air outlet connected with the air duct, and an air deflector guiding directions of air flow from the air-conditioner. A volute tongue is provided in the air duct and near an outer end of the air outlet. Wherein, the indoor air-conditioner unit further comprises a central support mechanism, which is elastically arranged between the central part of the back of the air deflector and the volute tongue, thus a complete seal of the air outlet can be achieved when the air deflector is closed, i.e., there are no gaps in the air outlet.