An electric heater may be required to heat the aircraft. The electricity emitted from electrical appliances increases the available heat. It dissipates available heat with a fan to blow air over the elements and into the cabinet. Other floor or side elements simply radiate heat to warm the cabin. Electric heating element heaters require significant aircraft generator output, which is better devoted to the operation of other electrical appliances. Therefore, they are not very common. However, their use on the ground, when powered by an electrical power source from a ground, preheats the cabin before passenger's board the plane and does not require extra electricity consumption. There are many different types of aircraft heating systems available, depending on the aircraft type.