Abstract: A solar heat regulating device selectively heats, with sunlight, the air in a building having a window therein and alternately shields and insulates the air in the building from the heat of sunlight. A frame is provided for mounting the solar heat regulating device inside the structure adjacent to the window. A plurality of hollow vanes each of which have a passageway therethrough. Each of the vanes has a heat absorptive surface on one side which allows solar radiation impinging thereon to heat the air in the passageways of the vanes. The vanes also have a heat reflective surface on another side. The heat reflective surface reflects the solar radiation impinging thereon and insulates the air inside the building from the heat of the sunlight. The vanes are rotatably mounted about vertical axes and spaced so that either the heat absorptive surfaces on the vanes or the heat reflective surfaces on the vanes may face the outside of the building.