Demand controlled ventilation: Sensitivity and robustness of the performances

Demand controlled ventilation (DCV) seems to be the main way to comply with both energy and internal air quality (IAQ) concerns. Largely spread in non-residential building since more than 2 decades (Fisk, 1998) because of large potential energy savings, its application for the residential sector is nowadays becoming the basis of ventilation systems for dwellings. Indeed, thermal regulations for residential buildings in several countries give targets that are difficult to reach with constant air changes rates. In France, the successive higher thermal regulation requirements have led to the development of humidity based DCV systems. Since a decade, it is considered as the reference system of ventilation. 
DCV strategy are developed under performance targets in order to reach threshold values for IAQ evaluation while minimising the energy impact. The performance based approach in France consist in making multizone simulation for each type of dwelling with fixed parameters. These lasts are the envelope leakage in each zone, the weather conditions (pressure coefficient, wind velocity and direction, temperature, external humidity), the domestic activities and occupant presence in the different zones. These fixed parameters enable to make objective evaluation between two systems and thus quantify the performance of each system. The inconvenient of such approach, and mainly the deterministic parameters used, is that DCV strategies are optimized for these specific cases and thus the DCV strategy might be less effective in real situation than the numerical ones. 
The present study aim to identify the global sensitivity of the DCV performance on these deterministic parameters. RBD FAST global sensitivity analysis is realized on a specific building configuration with a specific DCV system that comply with today French thresholds targets. Analyses are realized dynamically and thus integrates weather conditions variability on the sensitivity indexes. The most important parameters are highlighted as well as the influence of external conditions on the main indexes. Even though DCV strategy enable to comply with both IAQ and energy targets, their performances might be not guarantee for any cases for both, occupancy and building characteristics. Thus, the next issues migth be, how DCV could be more resilient in the future.