Quality test, diagnostic investigation of the building


Blower door test technician

Arch. Paolo Cornacchini

On the one hand it can be very useful to identify any defects during construction to be able to correct them effectively or carry out a diagnostic investigation on existing buildings before intervening with a renovation, or it may be of interest to the buyer or the client verify the correct execution of the works, check the quality or the absence of any problems.

Among the most effective verification tools used today, there are the Blower Door Test (or air tightness test) and the infrared thermal imaging camera (IR), in some cases used simultaneously.

The Blower Door Test is a non-destructive test and is used to identify air infiltration, verify the correct installation of the windows or a system laid dry like a wooden roof, a floor, a wall;

Due to the air permeability of the building envelope, cold air enters the cracks and cools surfaces and environments, making additional indoor air heating necessary and negating the construction of a well-insulated casing. In addition to creating annoying drafts of air, condensation is almost always formed at the drafts due to colder surfaces and therefore possible formation of mold, compromising the quality of living.

To avoid these problems it is important to achieve a good air tightness of the casing.

It is possible to evaluate the degree of tightness of a building through the Blower Door Test test: it is created artificially with an instrument, equipped with a fan that sucks or introduces air, a pressure difference between the inside and the outside of the building and the flow of air change due to infiltration is measured.

It is very useful to use this test during the construction phase or in existing buildings as it is possible to identify the imperfections and go to correct them effectively.

Furthermore, in homes with low energy consumption, a controlled ventilation system with heat recovery (VMC) is often used. The latter works as a system in balance between suction and delivery vents and it is essential that there are no uncontrolled drafts to avoid pulling cold air in from outside and compromising its correct functioning.