The main content of this design is to design the air conditioning system of a seven storey hotel. The building has seven floors in total, with a total height of 21.5m and a total construction area of 4600 ㎡. The first floor of the building is the reception hall and the tea room, with a floor height of 3.5m, the second floor is mainly the dining room, with a floor height of 3.0m, and the third to seventh floors are guest rooms, with a floor height of 3.0m. The main contents include: the selection of system form, the calculation of cooling load of rooms on each floor, the calculation of room air volume, and the calculation of air duct design; Water system design and corresponding hydraulic calculation; Equipment selection and layout, etc. Finally, the noise reduction, vibration prevention and corrosion prevention of the equipment are simply designed and explained. ...