All valves have been blocked to prevent moist outdoor air from entering the cellar.
The dry air is blown out through a system of pipes (yellow arrows) and is spread throughout the whole cellar when it is drawn back in to the dehumidifier (green arrows). The dehumidifier removes the moisture in an air current that is blown outside the house (blue arrow).
To minimise energy consumption, you should let a humidistat (moisture meter) control the dehumidifier. The humidistat starts the dehumidifier when the humidity gets too high, and turns it off when the humidity has dropped sufficiently. You can connect a control box to the humidistat with a lamp that warns you if the humidity is too high in the crawl space. The box is installed at a prominent place inside the house.