A range hood draws away moisture, odors, grease and heat while cooking on the stove. Gas ranges require range hoods to remove the potentially deadly carbon monoxide produced during combustion.
Range hoods that vent to the outside work best at removing unwanted cooking residue. Range hood size is measured by CFM, which is the cubic feet of air moved per minute by the fan. The size of the stove top helps determine the necessary fan size, which is 100 CFM per 12 inches of stove width. A large kitchen needs a larger range hood to properly remove all of the cooking remnants from the space.