Abstract Recently, we introduced a transparent capillary glass panel fabricated by lamination of a structured glass sheet and a thin glass cover used for liquid circulation. Major applications of such device are room heating and cooling and energy harvesting for heat pumps. In order to model a façade of a building, a story of a building or even the entire building, simplified but accurate models for the temperature and the fluid flow distribution within the capillary panel as well as a device optical and thermal model are necessary. In this paper, our simplified models are introduced.