I was interested to see that its power usage goes down the harder that it is working. I suppose that the diaphragm frequency slows at higher pressures reducing its ability/need to draw more power. Kinda makes sense to me now that I have seen the numbers. You actually use less energy at higher pressures at the loss of CFM.
All true but the reason the energy use goes down is because lesser quantity air is moved. At higher pressure, an air pump moves a smaller weight of air at a lower velocity and so it does less work at high pressure than at low pressure. The energy consumption is proportional to the product of mass rate of air and the square of its velocity at the discharge less losses of inefficiency.
