The invention discloses a central
flue system. The central
flue system comprises extractor hoods installed on different floors, air outlets of the extractor hoods communicate with a public
flue through
smoke pipes, electric check valves are installed in the
smoke pipes, and a flue main draught fan is installed in the public flue. The central flue
system is characterized in that each extractor hoodcomprises a draught fan and further comprises a master
control system and an electric
check valve control system; and in the state that the draught fans of the extractor hoods are started, the mastercontrol systems communicate with the electric
check valve control systems so as to obtain the starting state of the whole building, and therefore the running state of the flue main draught fan systemand the electric check valves is controlled. The invention further discloses an
air volume adjusting method of the central flue system. Under the premise that the indoor extractor hood draught fans are reserved in the central flue system, a main
machine is installed on a public flue opening, the problem that cooking fumes discharging is difficult for users on lower floors of a high-rise housing is solved, cooking fumes are efficiently purified, the whole building can still achieve cooking fume discharging when the main
machine breaks down, meanwhile, the use frequency of valve blocks of the electric check valves and the main
machine is reduced, the
failure rate of the valve blocks of the electric check valves and the main machine is reduced, and the service life is prolonged.