## 2 Methods  
### IAQ and Airflow Measurement Campaign  
The first campaign took place in winter between 8 February and 15 (C1) and the second was in spring from 2 to 9 April 2019 (C2). The campaign was conducted in a double storey detached house built in 2013 and located near Chambery, France, in a mountain climate. It is occupied by two non-smoker adults and two children. The volume of the house is 337 m\({}^{3}\) with a total floor area of 135 m\({}^{2}\). The house has four bedrooms, two bathrooms, two wash closets (WC), one mezzanine, and one kitchen opening into a living room and a hall, as shown in Figure 1. The indoor material finishes are plasterboard painted with A+IAQ label (walls and ceilings), wooden floors (3 upper bedrooms) and tiles (other floors and bathroom walls). The energy consumption design is for 39 kWhep-year\({}^{-1}\cdot\)m\({}^{-2}\), including low heating needs of 12 kWh\(\cdot\)year\({}^{-1}\cdot\)m\({}^{-2}\). The air leakage of the envelope is q\({}_{44\_\text{surf}}\) = 0.44 m\({}^{3}\cdot\)h\({}^{-1}\cdot\)m\({}^{-2}\), with tight internal partition walls: median value of q\({}_{50}\) = 0.8 m\({}^{3}\cdot\)h\({}^{-1}\cdot\)m\({}^{-2}\). In France, the current energy performance regulation RT2012 [33] requires that all new residential buildings must comply with a limit value for the French indicator q\({}_{44\_\text{surf}}\) (air leakage rate at 4 Pa divided by the loss surface area excluding the basement floor): 0.6 m\({}^{3}\cdot\)h\({}^{-1}\cdot\)m\({}^{-2}\) for single-family houses. An extensive measurement campaign has been conducted on this house in order to identify the spatial variability of external and internal air leakage [34], using the fan pressurization method described in [9]. In this campaign, the authors identified q\({}_{50}\), the air leakage rate at 50 Pa divided by the surface of the considered wall, as more suitable for quantifying airflows through internal partition walls. The house is equipped with one whole house balanced ventilation system with integrated heat recovery, and without any air recirculation. According to the French airing regulation [35], in this seven-room house with two bathrooms and two WC, the ventilation system must extract 30 m\({}^{3}\cdot\)h\({}^{-1}\) in each bathroom, 15 m\({}^{3}\cdot\)h\({}^{-1}\) in each WC, and 45 m\({}^{3}\cdot\)h\({}^{-1}\) in the kitchen. In the mezzanine and the 4 bedrooms, one supply vent is installed and two supply vents in the living room, all dimensioned for balancing the whole-house extracted airflow. All the ventilation components are located in Figure 1. As a result, the whole-house extracted airflow should be 135 m\({}^{3}\cdot\)h\({}^{-1}\), equating to an average dwelling air change rate of 0.4 h\({}^{-1}\). In addition to this \"base\" ventilation speed, a high-speed ventilation mode must also be able to extract 135 m\({}^{3}\cdot\)h\({}^{-1}\) in the kitchen during cooking periods, thanks to a dedicated ventilation exhaust component. Figure 1: Plan of study house: ventilation components and devices locations in each setting and their symbols (a) 1 st floor; (b) 2 nd floor. Ventilation components (supply, exhaust); symbols of devices (supply, exhaust); symbols of  
We can note that French airing regulation results in ACRs among the lowest in Europe, as shown by [36; 37]. Indeed, several European national regulations require that ACRs in whole residential buildings vary from 0.23 to 1.3 h\({}^{-1}\), with 0.5 h\({}^{-1}\) being a common reference value. The following parameters were monitored: temperature (T), relative humidity (RH), CO\({}_{2}\), TVOC, formaldehyde, the particle numbers and PM\({}_{2.5}\). The concentration of each parameter is measured every 10 min at least at two locations indoors and outdoors (Figure 1).