Indoor unit and air conditioning system

An indoor unit and an air conditioning system relate to the technical field of air conditioners and are used for solving the problem that condensed water in a water pan is easy to splash out of the water pan. The indoor unit comprises a machine shell, a first heat exchanger and a water pan. The first heat exchanger is arranged in the machine shell. The water pan is arranged in the machine shell, located below the first heat exchanger and connected with the first heat exchanger, a concave part facing the first heat exchanger is formed in the water pan, and the first heat exchanger extends into the concave part through an opening of the concave part. A sunken water guide part is formed on the water pan and located on the bottom wall of the sunken part, and the first heat exchanger is attached to the bottom wall of the sunken part so as to cover an opening of the water guide part. A water outlet is formed in the water pan, the water outlet is communicated with the water guide part, the water guide part is used f