The ventilation and air conditioning project of the 3 # public teaching building of Qilu University of Technology has a floor area of about 20000 square meters. The Kcalin modular integrated air conditioning system is used to realize the functions of cooling in summer, heating in winter and fresh air for the teaching building. A total of 16 130 air source heat pump units, 1 hydraulic transmission module unit, more than 50 hydraulic distribution module units, more than 400 terminal air conditioning boxes and fan coil units are used in the project. The modular integrated air conditioning system adopts the packaged design concept, which is convenient for transportation and quick for disassembly and assembly, effectively shortening the construction period and labor cost, simple for operation and maintenance of the system, safe and reliable, and saving 50% of the floor area of the computer room on the basis of energy saving and consumption reduction. The project was completed and officially put into use in November 2019.