This Excel spreadsheet creates a system curve graph, and on the same graph either a pump curve or a fan curve. It also creates the curve for two parallel pumps or two parallel fans.
You need to know the flow and pressure of one (non-trivial) point on the system curve. You need to know the flow and pressure of one (non-trivial) point on the pump or fan curve, and the top dead head pressure of the pump or fan.
090_System_Curve_Pump_Curve_Fan_Curve.xls
