Airtightness and energy impact of air infiltration in residential buildings in Spain

Addressing the airtightness of the building envelope is key to achieve thermal comfort, good performance of ventilation systems and to avoid excessive energy consumption. Previous studies have estimated an energy impact on infiltration on the heating demand between 2 and 20 kWh/(m2·y) in regions with temperate climates. In Spain, this issue has not yet been addressed in depth. This study aims to assess the energy impact of uncontrolled air flows through the building envelope in residential buildings in Spain.

Impact of a poor quality of ventilation systems on the energy efficiency for energy-efficient houses

The “VIA-Qualité” project (2013-2016) focuses on low energy, single-family dwellings. It proposes the development of quality management approaches (ISO 9001) which aim to increase both on-site ventilation and indoor air quality. One of the main benefits of those approaches is the improvement of ventilation system performance, especially thanks to a rigorous follow-up from design to installation. Efficient ventilation system performance is rewarded in the French EP-calculation, through a primary energy consumption estimation.

Energy and ventilation.

The energy statistics of OECD Countries shows that between 30-50% of primary energy is consumed in non-industrial buildings (i.e. in dwellings, offices, hospitals, schools etc.) Of this, as much as 50% is dissipated from the building in the departing air stream. As buildings become more thermally efficient, the proportion of energy loss (either heating or cooling losses) associated with ventilation and air infiltration is expected to become the dominant thermal loss mechanism. Additional losses may be associated with the energy needed to operate mechanical ventilation systems.