Variable air volume air conditioning system and air conditioning control method

The invention provides a variable air volume air-conditioning system and an air-conditioning control method, which can reduce the number of times of increasing and correcting the rotating speed of a fan and realize energy conservation and cost conservation. A variable air volume air conditioning system according to the present invention is provided with: a variable air volume controller (2) that sends static pressure overflow information for each variable air volume unit (1) on the basis of the opening degree of an air valve of the variable air volume unit (1); a re-determination unit (61) that re-determines the static pressure relief information on the basis of the indoor temperature or indoor CO2 concentration of the region to be controlled before integrating the static pressure relief information for each variable air volume unit (1); and a static pressure relief information changing unit (62) that changes the static pressure relief information for each variable air volume unit (1) on the basis of the dete