Abstract: A rectangular building contains a pair of light permeable panels which face in a southerly direction in order to receive as much solar radiation as possible. One of the panels constitutes one section of the building's sloping roof and the other a vertical wall of the building. The remainder of the building panels are mainly of sheet metal. Inside the building and spaced from both the light permeable panels are a pair of circular grain storage bins, each being open at the top but protected or covered by the overlying roof. Air heated by the radiation transmitted through the light permeable panels is induced to flow through each bin so as to dry grain or other crops contained in the bin. The air then passes through a gravel bed at the bottom of each bin into ducts having fans which exhaust the air and the moisture it has picked up to atmosphere.