A box type exhaust hood is a type of ventilation system commonly used in commercial kitchens to remove smoke, grease, heat, and other pollutants generated during cooking. It consists of a metal box that is installed above the cooking area and connected to a duct system that vents the contaminated air to the outside. The box type exhaust hood typically has a grease filter that traps grease and other particles, and a fan that pulls the contaminated air through the hood and ductwork.