Blower Pressure Draft (\( Pd \)):

\[ Pd = Ps \times Dg \]

Where:

• \( Pd \) is the blower pressure draft, in centimeters of water (cm of water).
• \( Ps \) is the specific pressure draft, in centimeters of water per meter depth of grain (cm water/m).
• \( Dg \) is the depth of grain in the bed, in meters (m).