The windmill starts functioning with soft breezes. It is only necessary a wind speed of max 4 m/s to start pumping water. With max 4 m/s, the wind-wheel begins to rotate in a vertical movement.
The rotation of the wind-wheel is transformed, through the connecting pumping piston, in a vertical movement, and this is transmitted to the pump. The pump (mainly a piston pump, but depending on water needs, other pumps are installed) has a piston and a system of valves that, in a way coordinated with the movement transmitted by the offspring, push the water until the surface and, if needed, to an altitude even higher than the windmill. One of the main characteristics of the windmills is that in case there is no further water in the ground the pump continues functioning without being damaged. The windmill not only works with just very low wind speeds, but also automatically stops in case of too strong wind. This is possible through an automatic brake system.