Patent ID: 7330770

Claim:
A fan selection method for selecting a fan required for cooling an inside space of a housing including therein an electric device that generates heat, said method comprising: providing a database comprising fan data including a maximum flow quantity Q 0 of each of usable fans of a plurality of types, and parameter data, the parameter data indicating a change in a flow quantity ratio between an effective flow quantity Q 1 and the maximum flow quantity Q 0 of the fan when an area ratio S 1 /S 2 of an opening area S 1 of an air vent provided at said housing to a sectional area S 2 of an air flow passage at the fan is changed, the effective flow quantity Q 1 indicating the flow quantity when the fan is operated; computing a required ventilation flow quantity by entering into a computational expression a predicted total electric power consumption of said electric device and a predicted rise in air temperature within said housing, said computational expression indicating a relation among the predicted total electric power consumption of said electric device, the predicted rise in an air temperature within said housing when cooling is not performed, and the required ventilation flow quantity necessary for the cooling; determining an area ratio S 1 /S 2 between the opening area S 1 of said air vent provided at said housing planned for use and the sectional area S 2 of the air flow passage of the fan planned for use, and determining from the area ratio S 1 /S 2 and the parameter data a parameter range of a proper flow quantity ratio required for the cooling; and selecting from said database a fan as said fan required for cooling that produces the maximum flow quantity Q 0 necessary for obtaining a flow quantity that falls between a required minimum flow quantity Q min and a required maximum flow quantity Q max , the required minimum flow quantity Q min being obtained by dividing the required ventilation flow quantity by an upper limit value of the parameter range of the proper flow quantity ratio, the required maximum flow quantity Q max being obtained by dividing the required ventilation flow quantity by a lower limit value of the parameter range of the proper flow quantity ratio.