Air fryers are much more energy-efficient than a regular oven for a few reasons. First of all, they have a much smaller capacity, so it takes only a fraction of the time to preheat it. The airflow system also allows it to speed up the cooking time, so it doesn’t have to run as long to cook the same meal. A regular oven cycles the heat on and off to maintain the temperature while the air fryer has it on all the time, but the other factors still keep the energy usage down, so an air fryer will use less electricity than an oven every time.