unsteady wind

Building airtightness tests have become very common in several countries, either to comply with minimum requirements of regulations or programs, or to justify input values in calculation methods. This raises increasing concerns for the reliability of those tests. Despite the extensive debates about how the building pressurization test standard ISO 9972 should address sources of uncertainties, no change has been implemented. According to the current standard, the zero-flow pressure shall not exceed 5 Pa for the test to be valid.

Air infiltration holds a central role in building energy consumption and is associated to several building physics phenomena. Air infiltration in buildings due to wind-induced pressure is a complex process, strongly influenced by the turbulent nature of wind. This extended summary highlights the findings of a series of studies with focus on unsteady wind and its impact on air exchangesin buildings. The focus is on wind gustiness and its relation to air infiltration under natural conditions.