Numerical evaluation of the air quality and thermal comfort in the cooking kitchen under exhausting effects of the range hood

This paper presented a numerical model with UDF programming to analyze the performance of the range hood for discharging particulate matter and improving thermal comfort. A benchmark experiment of stir-frying shredded potatoes in the kitchen environment was performed to validate the accuracy and reliability of the present numerical model. Based on the established numerical model, we examined the effects of the ventilation velocity, the outlet area, and their combination on kitchen air quality and thermal comfort. It was revealed that the particulate concentration at two test points reaches the maximum when the cooking stove is turned off. Also, the particulate concentration maintains around the peak regions for over 60 s before it decreases promptly. Moreover, the particulate matter tends to accumulate in the upper part of the kitchen and in positions with poor ventilation. In term of the thermal comfort, the face and shoulder areas of the human body encounter the highest dissatisfaction rate because the heat flow generated by the stove accumulates in the upper part of the kitchen. If the ventilation velocity and the outlet area grow, the temperature difference decreases as well as the air age, the PMV, and the PPD, resulting in better air quality and thermal comfort. Generally, to improve the kitchen environment, increasing the outlet area is more beneficial than increasing the ventilation velocity. The benefits are that the stable performance of removing kitchen particulate pollutants can be achieved, and less energies are consumed.