Comparative analysis of control strategies for passive cooling

Natural ventilation can be successfully applied for passive cooling in order to reduce cooling loads of buildings. Several parameters may have a significant impact on the performance of such a cooling technique, among others: climate, ventilation configuration, thermal mass, control parameters, etc. Within the frame of the PHACES project, a comparative analysis of control strategies in different configurations has been conducted, to underline and to quantify the relative impact of these various parameters. Some of these configurations have been experimentally tested. HybCell is a test cell implemented at LASH, DGCB, ENTPE, dedicated to the design, test and validation of control strategies for hybrid ventilation and passive cooling. The faade of this one-zone cell is equipped with six windows (tilt, top hung, vertically pivoted and sliding openings). The cell can also be ventilated using an extracting fan, and up to three virtual occupants can be experimentally simulated through sensible heat and CO2 production. A numerical model of this test cell has been validated, to be used as a numerical platform for such control strategies. Three European climates, seven ventilation configurations (up to three windows used for natural ventilation), various control strategies (including manual automatic combination) and control parameters (dead band and set point values) have been implemented. Relevant results are presented in terms of performance evaluated through the definition of performance criteria, dealing with thermal comfort, indoor air quality and maintenance of actuators.