Ventilation status of the residential kitchens in severe cold region and improvement based on simulation: A case of Shenyang, China

Residents tend to close the doors and windows of their residential kitchens in severe cold conditions, making insufficient outdoor air supply and aggravating indoor air pollution. In order to understand the ventilation and pollution status of the residential kitchens in a severe cold region and improve the ventilation system, this study used questionnaires, on-site tests, and Computational Fluid Dynamics (CFD) simulation to analyze a pollution and ventilation case in Shenyang, China. The method of using ceiling openings to compensate for outdoor air supply was proposed and optimized to improve air distribution in the residential kitchen. The average CO2 concentration in the breathing region, air velocity, and temperature levels in the kitchen, before and after the improvement, were compared. The results indicated that the kitchen pollution in severe cold area of Shenyang is serious, and the ventilation habit has regional characteristics. Furthermore, the overall kitchen environment including air velocity, temperature, pollutant levels, static pressure, CO2 concentration, indoor airflow fluctuation, and cooking fire were obviously improved for the ceiling make-up air cases. These findings provide a basis for improving the reasonable air distribution of residential kitchens in cold regions and for building a thermally comfortable environment.Implications: In order to understand the ventilation and pollution status of the residential kitchens in a severe cold region and improve the ventilation system, this study used questionnaires, on-site tests, and Computational Fluid Dynamics (CFD) simulation to analyze one pollution and ventilation case in Shenyang, China. The method of ceiling openings to compensate for outdoor air supply was proposed and optimized to improve air distribution in the residential kitchen. The average CO2 concentration in the breathing region, air velocity, and temperature levels in the kitchen, both before and after the improvement, were compared. The results indicated that the kitchen's air velocity, temperature, and pollutant levels are much better for the ceiling make-up air case compared with permeation and opening window cases. The static pressure, CO2 concentration, indoor airflow fluctuation, and cooking fire showed remarkable improvement in the residential kitchens. These findings provide a basis for improving the reasonable air distribution of residential kitchens in cold regions and for building a thermally comfortable environment.