This is a cool design – you can opt to have a breezy window during the clearer days or else shut it up and switch on the AC unit during summers. Italian company VentroVentilato has come up with this excellent system of simple double-or triple-glazed windows that incorporate a sensor-triggered fan. During winter, when the sun heats the air between the glass layers, the fan distributes the newly hot air into the room, providing heat. During summer, the heated air is conveyed directly outside the building. The company says that with this system, buildings will require far less powerful heating and air conditioning systems and thus helping in cost cuts.

[Core77]