Smart Mysteries of Soviet Architecture or What It Is and Why

These concrete visors are in one of the hospitals in Moscow.







It turns out that these are lamellar visors, which are installed to improve ventilation in the room.

The principle of operation is as follows:
Warm air in any room upstairs under the ceiling and wants to be even higher, and cold at the bottom slips.
When you open the window, the warm air from above begins to come out of the window into the street, creating a thrust that sucks in the colder air from the street. It's with a simple window.

If at the “exit” of warm air from the window to put a “wing”, like an airplane, the warm air at the exit from the room first drops down the profile of the wing, creating a lift like the wing of the aircraft, and even faster after leaving the edge will rush up, accelerating.

Thus, creating an even stronger craving for cold air at the bottom of the window, which will be sucked into the room faster.
Zero fan costs to speed up the ventilation of the room, the forces of nature are simply amplified by cunning.

Source: mirfactov.com/