Cooking. Manicure shops have chimneys, usually because employees in the shop need to cook for dinner, so they have chimneys. Chimney is a structure that provides ventilation for hot flue gas or smoke of boiler, stove, stove or fireplace. Chimneys are usually vertical, or as close to vertical as possible, to ensure the smooth flow of gas and draw air into the so-called chimney combustion or stack effect.