PURPOSE: To save energy of a centralized blower system by detecting the variation in totally demanded quantity of air for winders on the criterion of pressure inside a common intake duct and adjusting the flow rate of each of intake blowers.

CONSTITUTION: Air sucked from a plurality of winders 1 is further sucked by a plurality of intake blowers 4 via both a common intake duct 2 and a header 3. In this case the demanded quantity of air corresponding to the operating state of the winders 1 is calculated and the number of the intake blowers 4 which are to be operated is limited according to the calculated totally demanded quantity of air. Then if the totally demanded quantity of air for the winders 1 is varied at the interruption time due to the yarn connection other reasons, the variation in totally demanded quantity of air is detected as a variation in static pressure inside the header 3 with a pressure gauge 5 connected thereto and the quantative control for air sucked by the intake blowers 4 or the control for the number of blowers operated is executed. In such a way the totally demanded quantity of air for the winders may be in balance with the quantity of air sucked by the intake blowers, whereby attaining the energy saving of a centralized blower system.