In "Tiny Cooling Fan" of choice, we tend to compare pressure and wind, air pressure and air flow is normal ventilation. To overcome resistance within the cooling fan ventilation stroke, the cooling fan must overcome the air resistance generated pressure. This is the pressure. Pressure is an important indicator to measure the performance of the cooling fan. Pressure depends on the shape of the "Tiny Cooling Fan" fan, size, height and speed, the faster the speed, the greater the fan. Relatively greater pressure, duct heat sink design also better able to maintain the fan pressure. Fan impeller balancing done: Just as car wheel balancing to do, like wind turbine wind-screen machines also need to do this job, simply, is to keep the balance wheel in the operation of wind condition, reduce noise, and extend "Tiny Cooling Fan" fan life. Balance is a time consuming job, in fact, the final result may be in a part of the wind wheel plus weight stack it.