Believe it or not, it's likely in your house
Every home likely has HVAC sheet metal in one form or another. The common misconception is that just because your house uses baseboard heaters, it doesn’t have any ducting in it. But if your house is equipped with a stove, then it likely has sheet metal in it. Usually installed from the hood range to the outside to allow for ventilation of odors, grease, smoke and fumes produced by using the stovetop. Even common return air ducts allow for circulation.