There is no definitive answer to this question as it depends on a number of factors, such as the type of Chinese cooking being undertaken, the size of the kitchen, and the available ventilation. However, as a general guide, most experts agree that a minimum of 100 CFM (cubic feet per minute) is needed for effective Chinese cooking.
This is because wok cooking - which is often used in Chinese cuisine - requires high heat and strong ventilation to remove smoke and odors effectively. If your kitchen does not have good natural ventilation, then you will need to install an exhaust fan that can provide at least 100 CFM of airflow.