- Abstract The “kinetic wall” discussed in the First International Symposium in this series has been incorporated into a passive solar house that was built at Sede Boqer, Israel. The house has been lived in and monitored since October 1982. The present paper shows an analysis of the first winter's thermal performance figures of the rotating prism wall and compares it with some more conventional passive heating methods that are employed in the other rooms of the house. During the heating period from November 1st 1982 until March 31st 1983, the average ambient temperature at Sede Boqer was 10.5°C with a mean diurnal temperature swing of ±5.0° C . By contrast, the average air temperature in the room heated by the kinetic wall was 18.0°C with a mean diurnal temperature swing of magnitude less than ±1.0° C . No backup heating was necessary in this room. The rotating prism wall has proved to be easy to realize, convenient to live with and a remarkably effective space heating device.