Parallel operation is tied to use two or more of the "24V DC Cooling Fan". Parallel operation of the fan and the fan alone graph showing the volume of air flow generated by the two fans in parallel, only in the free space conditions, twice the single fan air volume, and when the fan is applied to the case of high system impedance connected in parallel, the system the higher the impedance, the parallel "24V DC Cooling Fan" can increase the amount of wind, the lower. Therefore, the application is only recommended in parallel in the case of low system impedance, i.e., in the case of the operation of the fan is almost completely free of air. Series "24V DC Cooling Fan" fan operation alone graph