Determination of the flow rates
The amount of air to be supplied to the house and discharged from it is defined in compliance with DIN 1946-6, depending on the surface area and the number of persons. An air exchange rate of 0.4 can always be applied as general value for the design of the ventilation unit for flats and single-family houses.
Example: At an air exchange rate of 0.4 h-1, a flow rate of 150 * 2.5 * 0.4 = 150 m³/h is required for a building with 150 m² living area and a room height of 2.5 metres.
Observe that the required flow rate also depends on the usage of the building and that a higher air exchange rate (intensive ventilation) must be possible for a greater number of persons.