220V Cooling Fan fan selection formulas

1, the standard state: that "220V Cooling Fan" fan inlet air pressure P = 101325Pa, temperature t = 20 ℃, relative humidity φ = 50% of the gas state.
2. Specify the state: that the fan intake unspecified condition. Including local atmospheric pressure or the local altitude, pressure inlet gas temperature and gas composition and import volume percentage of imported gas concentrations.
3, "220V Cooling Fan" fan flow and flow coefficient
3.1 Flow: is the unit volume of gas flowing through time fan inlet.
Represented by Q, usually unit: m3 / h or m3 / min.
3.2, "220V Cooling Fan" flow coefficient: φ = Q / (900πD22 × U2)