airtightness

The Presentations at the 43^rd AIVC - 11^th TightVent - 9^th venticool Conference: "Ventilation, IEQ and health in sustainable buildings" held in Copenhagen, Denmark on 4-5 October 2023.

Chile has 1,626 social housing complexes with a total of 350,880 dwellings. Several studies have demonstrated a low thermal performance and high air permeability of the envelope of social houses throughout the country, causing surface condensation on walls, high heat losses in winter and low levels of thermal comfort for their occupants. The presence of high levels of indoor pollutants and/or indoor humidity has also been observed, causing respiratory and cardiovascular diseases in the occupants.

The need for airtightness control is a reality given its impact on buildings’ energy use and IAQ. For the past few years, this fact has resulted in energy performance regulations being established in many countries in Europe and North America. However, compliance proof is not always required, and on-site testing is often avoided. In this sense, predictive models have become useful in the decision-making process and to estimate input values in energy performance simulation tools.

Due to the minimal energy requirement, the Passivhaus standard has been widely recognised and adopted to deliver low carbon buildings. To achieve this standard, the thermal and physical properties of the building envelope have to meet a stringent criteria. It has set out the highest requirement for the building airtightness, which requires the envelope to achieve an air change rate less than 0.6 h-1 when the building is subject to a pressure difference of 50 Pa. Building an envelope with such a high level of airtightness can be extremely challenging.

Maintaining the airtightness of building envelopes is a key factor for the energy efficiency of buildings. A fast and reliable detection of leaks plays a decisive role, especially during building renovations. For this reason, work has been done in recent years to apply an acoustic beamforming method that enables the fast, simple, and large-area detection of leaks in building envelopes. This method is based on a microphone array technology and assumes that sound primarily follows the same paths as air through the building envelope.