Abstract: The sample project for this analysis is ‘Liaoning science and Technology Museum’.In this project, the air-conditioning system design for an IMAX-film project room in cold region is written up. All-air system is used. Direct air-conditioning system is used in working time and primary return air system is for part time. Details are focused on the design calculation and switching between the two systems. When in direct system mode, part of the air supply is extracted from the auditorium. Required surrounding environment can be reached with proper filtration measures taken.

Key words: IMAX-film project room, film-based projection room, primary return air system, direct air system, switching