The phone rang, and on the other end of it was my father. ‘We’ve been thinking,’ he announced before we’d even exchanged pleasantries, ‘you need to get an air fryer. It’s the solution to these energy hikes.’

As a chef and writer with a couple of bestselling cookbooks under my belt, I was of course already familiar with the air fryer phenomenon. The countertop gadget, billed as more energy efficient than regular ovens, has been much hyped as a cost-saver as we face a winter of rocketing bills. But I’d quickly dismissed it as a fad. I had seen the chap with the characterful moustache from the Hairy Bikers waxing lyrical about how an air fryer and its oil-free cooking capabilities had liberated his beloved chips from his doctor’s red list; and yet, charming as he is, his endorsement had only strengthened my conviction that the air fryer was something I wouldn’t bother with. As someone who adores cooking, and who seeks solace and relaxation in kitchen tasks, I just didn’t think it was for me.

But my personal barometer for the seriousness of an issue is whether my father is twitching about it. So when a man who almost single-handedly keeps the local deli in business with his addiction to opulently priced charcuterie and imported patés started evangelising about the cost savings of switching from the Aga to an air fryer, my interest was piqued.

As my father continued extolling the air fryer’s virtues, I opened my laptop and carried out a quick search to see what this machine was really all about. My discovery? An air fryer is simply a mini convection oven. A fan circulates hot air from a heated element around the little chamber in which your food sits – so you’re baking, not frying. The surface of the food isn’t coming into direct contact with hot oil, making it lovely and crispy; instead it’s being baked, or dehydrated, with hot air, much like in your normal home oven.

So why air fry? Well, it is quicker. Ninja, the makers of perhaps the best air fryers on the market, claim it is 50 per cent faster than other methods when cooking sausages and fish fingers, a reliable enough metric for my tastes, although much of this speediness is simply a by-product of limited amounts of food being cooked in a small space rather than some genuine scientific genius. But it does mean that cooking a sausage, for example, takes only 15 minutes, as opposed to a ten-minute pre-heat and then 20 minutes in a normal oven – and thus that sausage (or that pack of sausages) costs around 10-15p in energy to cook in an air fryer as opposed to 40-50p in the oven. Ninja also claims that cooking chips in an air fryer is 75 per cent healthier than deep frying them, which I wouldn’t question, although I would argue that your classic oven chip might stand up equally well on the same metric.

‘We listened to a podcast’ – we are back with my father; he is reaching a crescendo – ‘they turned everything off, the lights and everything, and cooked a baked potato in an oven, 34 pence. Not bad, hey? The cost of cooking the baked potato in the air fryer? Guess.’ ‘20 pence,’ I mumble, hoping to give enough leeway for anything less to be suitably impressive. ‘Four pence,’ comes the reply. ‘For two baked potatoes. That’s two pence a potato.’

Thanks to enforced smart meter installations and the availability of energy monitors that tell you exactly how much power your appliances are using, almost anyone can now calculate the cost of cooking a baked potato, reheating a Charlie Bigham's fish pie or rustling up a Sunday night sausage. Watching the money drain away is clearly a painful exercise – hence the move in my father’s household towards the seemingly frugal air fryer. Surely there’s an upfront cost to this cheap way of cooking, though? Sadly there is, with prices ranging from £130 to £230 for a decent air fryer from leading brands such as Ninja, Tefal or Philips. This will normally get you a countertop box with a slide-out basket for placing your food inside, but with nothing extra such as racks, pans, grids or grates that can be used to stack food or ensure things are cooked in a specific way.

So if it is just a small convection oven, why not simply buy a small convection oven? I put this to my father when I manage to get a word in – and he dismisses it with a ‘harrumph’. I guess the PR just isn’t as good. In fact, Sage, the maker of the best countertop convection ovens on the market, has now performed an about-turn and started to refer to its market-leading convection oven as having ‘air fryer’ capabilities. This Sage Smart Oven Pro might set you back more than £200, but comes with all the extras you’ll need, as well as offering much more versatility in what it might produce: perfect pizza, a sourdough loaf and even toast being three things that most certainly can’t be achieved in an air fryer.

To make matters even more confusing for air fryer disciples, market leader Ninja has now developed an 8-in-1 countertop flip oven, which does exactly the same as their air fryers but in the shape of a small countertop oven – presumably anticipating the realisation that air frying is simply cooking in a convection oven, and making sure they secure a piece of that pie when the market catches on. Is this an admission that the air fryer itself was an invention no one needed? That convection cooking just needed a rebrand as ‘air frying’?

Yes and no. If you want cost-effective chips, chops or cheese on toast for two, the air fryer could be your knight in shining armour – but only by a whisker. Using the grill on your regular oven costs about 9p per ten minutes of usage, so preparing cheese on toast might set you back 7p in total. This is much the same as it would cost in the air fryer. If you want to make a meal with a few components, though, or if you have another couple joining you for a kitchen supper, the air fryer will have you rotating multiple dishes through its little basket. You’ll have to contort yourself in order to keep hot the things that are ready, while you wait for the things that still need cooking to cook. And you’ll end up running the thing for a good long time, all but diminishing that cost-of-living busting advantage.

My advice? If you want a separate, cheaper-to-run oven, buy a little convection oven such as the Sage one mentioned above. It is more versatile, for sure, but with a small chamber heated via the same clever convection technology as the air fryer, you get almost all of the efficiencies, both in terms of time and money. You can cook multiple things at once; bake a cake; use a pizza stone to cook a pizza; prepare your chips, baked potatoes, fish fingers and more; and you can do all of this using your normal roasting trays and racks. If that isn’t enough, you can cook things low and slow, as well as hot and heavy, meaning Middle Eastern lamb shoulder or Sichuan pork belly are possible in a way they wouldn’t be with the air fryer.

So while it might not do your baked potato for 4p, a countertop convection oven will see you right for much more of your daily cooking – and it won’t be half as tough to watch on the smart meter as that big range cooker or Aga.

Benjamin Benton is the co-author of Max's Sandwich Book, publisher at Saturday Boy Books and writes a weekly food newsletter on Substack, No Cartouche.