Recuperation is mechanical ventilation with heat recovery.
Traditional gravitational ventilation is based on the draft (suction of air) produced by the chimneys, but it has many disadvantages, including, among others, cooling down the house and not removing moisture from the rooms.
Recuperation, being a mechanical ventilation, is based on the air movement produced by the machine, a device called a recuperator.
The recuperator makes it possible to control the movement of supplied and removed air from the rooms and the recovery of heat from the already warm but dirty (humid and carbonated) air.