Exhaust rate for range hood at cooking temperature near the smoke point of edible oil in residential kitchen. (January 2022)

• Record Type: Journal Article
• Authors: Xie, Wuhao; Gao, Jun; Lv, Lipeng; Cao, Changsheng; Hou, Yumei; Wei, Xiaobin; Zeng, Lingjie
• Is Part Of: Journal of building engineering. Volume 45(2022)
• Publication Date: 2022-01
• Subjects: Range hood -- Exhaust airflow rate -- Kitchen ventilation -- Cross draft -- Smoke point; Building -- Periodicals; 690.05
• DOI: 10.1016/j.jobe.2021.103545
• Languages: English
• ISSNs: 2352-7102

Abstract

Abstract: The discharge capacity of the range hood for cooking-related pollution under current exhaust airflow rate (EAR) standard of 300–500 m 3 /h is limited when cooking temperature near the smoke point of edible oil. This study endeavored to determine appropriate EAR for cooking temperature varies from 200 to 300 °C, which comprised smoke points of different edible oils, considering whether the kitchen was ventilated with the adjacent room or not, and the cooking position of the left/right stove. Particles generated from a simplified cooking process of oil heating test, tracer gas experiment, and flow visualization experiment were conducted. CFD simulation with capture efficiency as an evaluation index was performed. Evidence is presented that when the cooking temperature is 200 °C, the pollutant control effect does not change much when the EAR is above 700 m 3 /h, while an EAR of 800 m 3 /h may be necessary at 300 °C. For open-door and closed-door cooking, a minimal difference exists in demand for a suitable EAR in this local ventilation system. However, the hood continues to exhaust air during post-cooking period, thereby showing that a higher EAR is necessary to control the pollutants in open-door cooking. The primary and secondary cross draft airflows caused by different air supply positions are observed, which play a vital role in selecting suitable left/right cooking position. The location of the left stove is conducive to the elimination of cooking-related pollutants due to primary cross draft, while it is the right stove due to secondary cross draft. Highlights: The appropriate exhaust rates of range hoods at cooking temperature near the smoke point of edible oil were determined. Oil fume capture was compared at different exhaust rates when the kitchen is ventilated with or without an adjacent room. Cooking patterns of left and right stoves with natural make-up air distribution were discussed. Primary and secondary cross draft airflows induced by different air supply positions were observed.