Proper kitchen ventilation will remove all the greasy, smoky, steamy, gaseous byproducts that you don’t want hanging around. Catch the byproducts with an updraft or a downdraft and send them totally out of your home or through a system that recirculates filtered air. Which system you choose will depend on the layout and structure of your kitchen, your local building codes, and your own style preferences.
You’ll pay more for systems with higher airflow and lower noise ratings. That’s where knowledge of CFMs and sones will come in handy. CFMs refer to the amount of cubic feet of air a vent system can move per minute. The National Kitchen and Bath Association recommends a 150 CFM minimum for all surface cooking appliances. Sones measure noise level. Fun facts: A refrigerator equals about 1 sone; ordinary conversation about 4; and a jet plane landing about 256. The Home Ventilating Institute recommends that kitchen vent fans should not be louder than 9 sones.