This NORDTEST method applies to the determination of the total outdoor airflow into buildings, by means of tracer gas, according to the "decay method".
Outdoor air inflow can be created by a mechanical ventilation system and/or matural ventilation as a result of wind influence and temperature differences between indoors and outdoors.
The method is primarily applicable to single-family houses, flats, and cell offices. It can be used to determine
- the total outdoor air inflow or air from an adjacent space into a whole single-family house or a whole flat
- the total outdoor air inflow into an individual room at specific air flow conditions.
The method instructions and the given accuracies presuppose that' the outdoor air inflow amounts to at least 0.25 house, flat, or room volumes per hour.
It must be observed that, generally, the method is only applicable when determining the total air inflow into a whole house or a whole flat. However, the method may be used as determine the total air inflow into an individual room with closed doors. The preconditions for this being that the air flow conditions are such that the tracer gas concentration in surrounding rooms is zero.