You will need a large air fryer, at least 8 quarts in size, to cook a larger, 5-pound brisket. If you have a smaller air fryer, such as a 4 quart or similar, you can choose a 2-3 pound brisket and cut the recipe in half. If you have a small air fryer, less than 4 quarts, you can first check to see if the meat will fit or cut it into small pieces and cook in batches.