wagon

In low-energy and passive houses, about 80 % of the total energy is consumed for fresh air heating or cooling, the reason being the improved thermal insulation and air tightness of such a building. In fact, actual trend of building construction is to keep the windows closed. A similar situation is already encountered in some means of transportation, i. e. air-conditioned trains. Ventilation of the passenger space is assured mainly by a mechanical ventilation and, when the train stops, by a natural ventilation through door opening.