Natural and/or mechanical ventilation. Naturliche und/oder mechanische luftung.

In most office buildings, the continuous renewal of air cannot be guaranteed by means of ventilation through windows during any optional time. It is known (in the case of radiators and window ventilation) that when a window is open the ventilating heat cannot be recovered and other heat losses will occur.< The paper proves that the heating of a building by air is a greater energy saver then the conventional solution through static heating and window ventilation. The investment costs for a mechanical ventilation plant are higherthen the same costs for a heating plant, but this is balanced by the energy saved.