I was reading
this artcle about air fryers in BBC Good Food and basically they are a very tiny small oven in a bucket. They are no more and no less healthy than a normal oven, just cheaper to run... then came this, about the different types.
'Mini oven’ types: these models use convection or fan technology to cook food on flat, slide-in trays. As well as roasting, their extra air frying functions circulate hot air around the food for more efficient crisping. These took up the space of an average-sized microwave. Some may also include rotisserie elements.
So, I actually do own an "air fryer" but it is known as a mini oven. It can also do toast, bacon, burgers or chops under the grill, and rotisserie chicken and joints. As a bonus it also does "fake" proper chips.
Note: Proper chips are deep fried in beef dripping. Always - nothing else.