Wintergardens and many other buildings run hot during summer time. If there is no control, it might be rather hot in the rooms, if sun burns down.
The invention is not really big, but it works fine: if the sun shines, the sun produces some electrical energy by a small photovoltaic panel. The Panel delivers 12 V and 20 Watts under a load of more than 1 Amp. The voltage rises to 18 V without load. So I selected 24 Volt ventilators, running very quiet with 18 V. The ventilators are dimensionated to change the whole volume of air in a room in less than one hour. A Tiny Control box stops Brown out conditions and shall deliver some energy to a battery. The battery will be designed to cool the room during night, when the outside temperature is low. The control is just under construction, but the functions are designed.
The whole system works without any other energy source, than photovoltaic. At the moment, overheating is reduced from 20 Degrees down to 3 Degrees, in relation to outside air temperature. As the hot air is blown out through automatically closing vents, there are no air currents in the room. Living in the room is quite comfortable.
One later step may increase the comfort with some kind of photovoltaic climatisation, but the development uses some more efforts.