Fan Formulas and Affinity Laws

In fan engineering, standard air is considered to be air with a density of 0.075 lbm/ft3 when English units are used and 1.2 kg/m3 when SI units are used. Commonly applied industry values for standard air are shown in Table 32-1. For moist air, it is common to assume a humidity of 50% and a temperature of 68°F (527.7°R) in English units and 20°C (293.2°K) in SI units.

Flow rates may be considered on a mass or volumetric basis. On a mass basis, the flow rate is the mass of the

If the fan draws directly from atmosphere:

If the fan discharges directly to atmosphere:

Fig. 32-5 Blade Design for Backward, Radial, and Forward Tips. Source: Buffalo Forge, The Howden Fan Company

Table 32-1 Commonly Applied Industry Values

Guide to Alternative Fuels

Guide to Alternative Fuels

Your Alternative Fuel Solution for Saving Money, Reducing Oil Dependency, and Helping the Planet. Ethanol is an alternative to gasoline. The use of ethanol has been demonstrated to reduce greenhouse emissions slightly as compared to gasoline. Through this ebook, you are going to learn what you will need to know why choosing an alternative fuel may benefit you and your future.

Get My Free Ebook

Post a comment