The actual situation: the      cinema halls have an area from 200 to 800 m2 each.

Solution: Mount the air      purifiers directly to the air conditioning pipes for the cinema halls in      the equipment room.

Effect: When the air quality outside      with PM 2,5 no more than 300 ug/m3, the air quality inside the cinema hall      has a PM 2,5 less than 35 ug/m3, and this wins the appreciation from the      cinema staff and the audience.