This paper discusses the slow drying of wood chips stacked in deep beds by a flow of ambient air throughout the major part of the year. This kind of drying operation introduces some simplifications to the equation system. The celerity of the drying front is described by an analytical term, then the shape of the front is obtained by an ordinary differential equation. The meteorological data which has been put into the computer determines the progress of the drying front. The flow rate of the blower is determined from the operation characteristics (time allowed, height of the pile, moisture of the product, regulation function) and from the data of the local climate. An additional rudimentary solar collector can improve the efficiency of the system. A period of ten days will be sufficient to calculate the mean data in order to ascertain the progress of the front.