Effective heat dissipation requirements should be decided early in the "24V DC Cooling Fan" system design, the most important thing is to heat elements provide adequate air flow and give appropriate space, power and other design and planning, select fans are considerations include air traffic demand, AC or DC power, rated voltage, speed, life expectancy, heat, lock protection and different audible tones and so on. "24V DC Cooling Fan" can be taken in any direction fixed basic heat transfer equation: H = Cp × Wx △ T where H = heat transfer capacity Cp = specific heat of air △ T = temperature rise within the device W = weight of our air flow friend W = CFM × D where D = density of air through the after substitution, we get: "24V DC Cooling Fan" by the conversion factor (conversion factors) and substituted into the sea level air density specific heat, heat dissipation can be obtained the following equation ; CFM = 3160 × kW / △ ℉