ABSTRACT
In this system an air collector is connected to building integrated heat storage. The air is circulated in a closed loop by natural or fan-forced convection through the collector to the storage and back to the collector. The room-facing surface of the storage discharges heat by radiation and convection to the heated space. A simple temperature difference control between the collector and the storage operates the fan. Reverse air circulation during the night is avoided by a damper located below the collector.
