Evaluation methodology and implementation for natural ventilation control strategies

This paper describes a methodology for evaluating the effectiveness of various control strategies for the operation of window actuators to control the indoor climate, and their implementation in a full scale case study building. In this study, the effectiveness of a control strategy is considered in terms of the capability of the controller for maintaining the indoor thermal comfort in a prescribed variable range, and its effect on the minimisation of the operational energy consumption of the building, due to a lower thermal energy demand to be met by the heating and cooling system. A model of the case study building, the award winning Team UOW Solar Decathlon house, was developed and calibrated with measured data. A control strategy was simulated using the ESP-r tool as a building simulator and the Building Control Virtual Test Bed (BCVTB) as a flexible control strategy development platform. The measured states and disturbances of the system from ESP-r are sent to BCVTB at each simulation time step, to determine the windows opening percentage at the next time step. The controller and the house response were simulated in summer conditions in Sydney, and the results from the house with only mechanical cooling, when using natural ventilation only at daytime and when using natural ventilation also at night time have been compared. The base thermal demand of the building, with only mechanical cooling, was reduced by 28.9% using natural ventilation at daytime, and by 54.9% using natural ventilation also at night time