Requirements of the DIN 4108 ‘Heat Insulation in Structural Engineering’ as well as plenty of damages caused by moisture convection make air-tight constructions and junctions necessary. The ‘BLOWER-DOOR-Method’ has proved itself in verifying the air-tightness, or rather, in showing leakage.
This kind of measurement is also necessary to prove the standard of EnEV-houses as well as so called ‘3-litre-houses’ and ‘Passivhäuser’. During this measurement, a ventilator is installed in an air-tight way in an aperture and differences between the pressure inside and outside can be produced.
The resulting airflow is a measurement of the shell’s air-tightness.