An exhaust hood is used over cooking equipment in a restaurant to remove the Exhaust from gas equipment or even steam from the kitchen. If you have gas equipment underneath the hood or are doing any frying you will be required to have fire suppression with the hood. If you have just an electric range or oven underneath the hood you may not need the fire suppression. It is always best to check with your local fire marshal to understand the rules of your jurisdiction. These hoods are made with stainless steel. They can come with galvanized steel or stainless steel filters. You may also want to order them with a stainless steel backsplash for your wall.
An exhaust fan is used in conjunction with an exhaust hood. It is placed on the outside of the building. It can be placed on a side wall or the roof. These fans are designed to pull the exhaust from the restaurant outside. The common way to size the exhaust fan is by CFM (Cubic Feet per Minute). For a small establishment you may use a fan as small as 800 CFM.