Forced air heaters use a fan to blow air that is warmed by metal or ceramic heating elements. A forced-air heater is appropriate for quickly heating up a small- to medium-sized room. It is ideal for use in large construction, commercial, and industrial sites. It is effectively a very hot flame with a large fan running behind it pushing huge amounts of cold air past the flame. These heaters can be operated using different fuels such as natural gas, propane, and kerosene.
A forced-air heating system draws the room air through ductwork to a furnace, where the air is filtered and heated. The warmed air is then blown back into the rooms through other ductwork. The system's ductwork is usually metal wrapped in insulation to help keep in heat. In some cases, flexible ductwork is preferred.