Ventilation system and method for controlling such a ventilation system

A method for controlling a ventilation system comprising:

• an array of fans configured to draw air from an enclosed space in parallel with each other, the array of fans comprising a set of variable speed fans, and
• a control unit programmed to actuate the array of fans according to a plurality of ventilation levels, a respective total flow rate value of air flowing in the enclosed space being associated to each ventilation level of the plurality of ventilation levels, each ventilation level being distinguished by a respective number of switched-on fans of the set of variable speed fans and by a respective rotation speed of the variable speed fans,
• wherein the control unit is further configured to determine an actual value of static pressure associated to the array of fans, calculate, on the basis of static efficiency curves associated to the variable speed fans, a provisional value of the rotation speed of the variable speed fans that maximizes a static efficiency of the variable speed fans at the actual value of static pressure, and for each ventilation level, calculate and store in a memory the rotation speed of the variable speed fans associated to the ventilation level and the number of switched-on fans of the set of variable speed fans associated to the ventilation level, on the basis of the provisional value of the rotation speed of the variable speed fans,
• wherein the method comprises the following steps performed by the control unit:
• a) determining the actual value of static pressure associated to the array of fans,
• b) calculating, on the basis of the static efficiency curves associated to the variable speed fans, the provisional value of the rotation speed of the variable speed fans that maximizes the static efficiency of the variable speed fans at the actual value of static pressure,
• c) for each ventilation level, calculating and storing in the memory the rotation speed of the variable speed fans associated to the ventilation level and the number of switched-on fans of the set of variable speed fans associated to the ventilation level, on the basis of the provisional value of the rotation speed of the variable speed fans, and
• d) actuating the array of fans according to the plurality of ventilation levels.