Static Pressure Curve
The vertical axis labelled "Inches of Water" describes relative air pressure.The horizontal axis labelled “Airflow (CFM)” describes Airflow volume in relation to air pressure.
The curve tells the user approximately how much air a fan will move for a given pressure reading. For instance - the curve meets the horizontal line at the bottom of the graph at about 290 (Cubic Feet/Minute). Look left along the bottom horizontal axis and notice that the air pressure (Inches of Water) is zero (No pressure difference at all between the inlet and outlet side of the fan.)
Notice that the curve meets the vertical axis at about 0.90 (Inches of Water) and that airflow is 0 (zero).