Computational aspects of modeling different strategies for kitchen ventilation: a comparison between the multi-zone approach and CFD modelling with reference to predicted indoor pollutant concentrations

This paper deals with the evaluation of different simulation approaches to kitchen ventilation modelling. Multi-zone, CFD and zonal approach are discussed. The investigation moves its steps from the analysis of a controlled ventilation system intended for individual and collective housing. The question of natural ventilation being able of ensuring ventilation rates consistent with acceptable indoor air quality is dealt with. Buildings have become increasingly airproof and natural ventilation, as it will be presented, may result inadequate. It follows that ensuring a proper airflow by mechanical means is necessary to provide occupants with good IAQ. The analyzed ventilation system supplies the main rooms (living rooms and dining rooms) with fresh air. Air sweeps through the occupied space and eventually is extracted by means of grilles located in the technical rooms such as kitchens and bathrooms, i.e. the rooms that are the most polluted as a result of every day life. The objective is to develop a design model suitable for long term, whole year, analysis that is able to offer advantages over multi-zone models without the issues associated with CFD modelling. Different flow scenarios have been tested. Well mixed and zonal modelling results have been compared to CFD predicted pollutant distribution which has been used as reference solution. CFD simulations have been validated by means of literature available experimental data. Sensitivity analysis has been performed to determine the impact of various modelling parameters on the accuracy of the simulation. In particular, the influence of capturing local effects, such as the plume rising from the cooking range, is presented.