Airflow Network Analysis and Control Strategy Design for Toronto High Rise

The development of a user-controllable natural ventilation scheme for a 12-story academic building in Toronto required the analysis of a complex airflow network, including two solar chimneys, and the subsequent development of a robust strategy to control individual floor and room airflow rates independent of solar radiation and outdoor temperature. TRNSYS and the TRNFlow component were used to model a simplified representation of the building airflow network and identify key performance characteristics. After ensuring adequate sizing of key airflow elements, a minimal control strategy was developed and tested. This ‘hybrid’ control strategy relies on a limited number of façade sensors and actuators compared to a fully automated strategy. Active controls provide an adjustable upper limit on possible airflow while relying on and enabling room occupants to adjust manual facade windows to intuitively control room temperature and air quality as they choose. This paper will review the analysis methodology and explain the intent behind the novel, yet simple, control scheme implemented.