In this study we estimate the air leakage distribution of single-family dwellings in Catalonia and use\ud a statistical analysis of an airtightness database for single-family dwellings in France to identify the\ud building characteristics that have the greatest influence on airtightness. The most significant variables\ud are found to be the structure type, the floor area, the age of the building, the number of stories and the\ud insulation type. A multiple linear regression technique is then applied to establish a predictive model for\ud deriving an estimated value of airtightness from these characteristics. To estimate the infiltration airflow,\ud a stochastic simulation of the building characteristics was performed per census tract using real data on\ud the distributions of building variables taken from the census information. The model is then applied to\ud determine the power law coefficient and the airtightness distribution. The predicted flow coefficients are\ud combined with the AIM-2 model and given meteorological conditions to determine the infiltration\ud airflow. Two sets of meteorological conditions are considered: average conditions and extreme conditions\ud for each season.Peer ReviewedPostprint (published version

Historic building restoration and renovation requires sensitivity to the cultural heritage, historic value, and sustainability (i.e., building physics, energy efficiency, and comfort) goals of the project. Energy-efficient ventilation such as demand-controlled ventilation and heat recovery ventilation can contribute to the aforementioned goals, if ventilation concepts and airflow distribution are planned and realized in a minimally invasive way. Compared to new buildings, the building physics of historic buildings are more complicated in terms of hygrothermal performance. In particular, if internal insulation is applied, dehumidification is needed for robust and risk-free future use, while maintaining the building’s cultural value. As each ventilation system has to be chosen and adapted individually to the specific building, the selection of the appropriate system type is not an easy task. For this reason, there is a need for a scientifically valid, systematic approach to pair appropriate ventilation system and airflow distribution solutions with historical buildings. This paper provides an overview of the interrelationships between heritage conservation and the need for ventilation in energy-efficient buildings, regarding building physics and indoor environmental quality. Furthermore, a systematic approach based on assessment criteria in terms of heritage significance of the building, building physics (hygrothermal performance), and building services (energy efficiency, indoor air quality, and comfort rating) according to the standard EN 16883:2017 are applied.

As ventilation systems become more sophisticated (or ‘smart’) standards and regulations are changing to accommodate their use. A key smart ventilation concept is to use controls to ventilate more at times it provides either an energy or IAQ advantage (or both) and less when it provides a disadvantage. This paper discusses the favorable contexts that exist in many countries, with regulations and standards proposing ‘performance-based approaches’ that both enable and reward smart ventilation. The paper gives an overview of such approaches from five countries. The common thread in all these methods is the use of metrics for the exposure to an indoor generated parameter (usually CO₂), and condensation risk. As the result, demand-control ventilation strategies (DCV) are widely and easily available on the market, with more than 20–30 systems available in some countries.