Named for French engineer Felix Trombé, who designed them in the 1960s with architect Jacques Michel, Trombé walls use a form of passive solar design to manage building temperatures throughout the year.
Especially valuable in colder climates, these walls have a layer of glass on the outside, and a solid section of high heat capacity material with openings for air on the inside. The windows allow short wavelength light to pass easily, and the wall traps that energy, converting it into longer wavelength heat radiation, which doesn't move through glass as easily. This combination allows the sun to heat the interior air, which then disperses slowly through the structure, helping boost heat throughout the night.
The walls themselves have many variations. Some have vents, others are completely solid. Some cover the full surface, while others are only half the height of the windows they abut. Some feature secondary windows, which may open and close for manual adjustment, some have exterior slits for better cooling on warmer days, and some even include fish tanks built right in to trap additional heat.
The concept of these structures dates all the way back to 1881, when they were first patented by Edward S. Morse.