Numerical evaluation of hybrid ventilation controlstrategies

This paper deals with the development and the evaluation of hybrid ventilation control strategies, using both natural and mechanical modes, in residential buildings using a graphical simulation tool. The description of a library of airflow components and macroscopic pollutants models used to simulate the demand controlled ventilation based on indoor pollutant concentrations is provided. The paper discusses the issue of implementation of ventilation control strategies based on occupancy and indoor air quality using “Stateflow” and integration into thermal-airflow modelling using “Simulink”. The case study is a single family dwelling that is used within the European project RESHYVENT. Two demand control strategies have been developed for the hybrid ventilation system. Yearly simulations have been performed in four European climates using the SIMBAD Building and HVAC toolbox, for the evaluation of hybrid ventilation control strategies. The assessment criteria used, are related to indoor air quality, to thermal comfort, to energy consumption and to the stability of control strategies. This work shows the possibility of using a graphical simulation environment for thermal-airflow computation. It is applied to the assessment of hybrid ventilation systems and concludes that the latter can improve indoor air quality and to reduce fan energy consumption with respect to reference system while maintaining the same building energy consumption for heating.