You're viewing a single thread.
Convection ovens. The branding of 'air fryer' always makes me cringe.
I was like you once and believed a convection oven and air fryer are the same thing and produce the same results. But I was wrong!
There is a subtle but crucial difference between an air fryer and a convection oven. A convection oven only circulates air around inside the oven, keeping the steam trapped with the food, while an air fryer actually removes all of the steam away from the food, allowing it to get much crispier much faster than is possible with a convection oven.
You are kind of right though, because now that air fryers have become popular, they've started marketting small toaster-oven-style convection ovens as "air fryers", even though they legitimately are not air fryers and do not cook the food the same way that an air fryer does.
so an air fryer is more like a small convection oven?
if you want the steam to escape, you can just open the oven door for a few seconds and there it goes.
also the air circulation is more intense in an air fryer, and it's a smaller enclosed space which is easier to keep at a high temperature. both of these also help food cook more evenly.
I wonder if I could DIY an air fryer with a heat gun, a metal box, and a PID controller.
Hmm. Diluting the air will be the hardest thing: A run off the mill heat gun will do 600C at 2000W in a concentrated stream, if you regulate it down to air frying temperature you'll get very little total power so you'll want to cool it down by pulling in additional ambient air instead. But with that out of the way... add a metal box and a timer? The heat gun already regulates the temperature. Probably not via PID though, just pre-set power levels for coils and fan they're not exactly precision instruments.
...and all that made me wonder and apparently there's no culinary heat guns which would be a smart choice because they'd pay attention for all materials to be food-safe. But there are hobbyists reporting great results using standard heat guns instead of the usual torch. Not, to be honest, that you'd expect standard lighter gas to be food-grade, of course.
I wasn't thinking of trying to regulate down the power on the heat gun itself, I was thinking of cycling it on and off (or cycling between heat and fan-only mode) to maintain thermostatic control of the temperature in the box.
Set a temperature, have an exhaust, the temperature inside will be within a wibble of your set-point because the air stream will completely dominate over any other source of temperature raise/drop. You're way overcomplicating things. Forego subtlety, consider the air as a bulldozer: If this was a closed system having feedback control would be a good idea but air frying is supposed to use fresh outside air so that the hot air is really dry and the intake air being a couple degrees hotter or colder won't make a difference in practice. Just smash that shit.
That would help, but I doubt it would be as effective as a real air fryer that is actively blowing air while heating it, instead of just circulating it. An air fryer gets really loud because it is moving so much more air.
My oven has gas burners in the top and bottom of the oven, and a tiny fan in the back for convection bake. The wee fan is meant to help distribute heat evenly throughout the oven. Convection is meant for baking multiple trays on both racks - it spreads the heat evenly throughout.
The air fryer has a big fan right behind the big heating element, which sits a few inches above the food, and blasts heat directly onto the food.
Similar components, but entirely different results.
Your comparison is rightly dispels the misconception that any “frying without oil” is happening though. An air fryer is closer to an oven, convection or otherwise, than it is to a deep fryer and pan-frying with oil. You just won’t get the same speed or results with a convection oven, though. They’re different designs.
I'm not entirely against calling it frying, in both cases you have heat transfer by immersion in a dry liquid as contact medium, as opposed to heating with infrared radiation (e.g. toaster, many kinds of spits), direct contact with no or little contact medium (hot pan with no/minimum oil, waffle iron), using water (which is wet) as contact medium which invariably makes things soggy instead of crispy and thus very different, or directly moving the atoms in the food (microwave).
That is: If you have a look at all the different ways to transfer heat into things then frying and baking are actually darn close to each other in the first place, compared to the rest. It's the reason you can definitely make a passable calzone in a pan. And air frying in particular brigs baking into the frying range of crispiness so I'd say fair is fair, you can fry with air as long as you make you air mean enough.
Any decent electric convection oven has an element around the fan. Mine is 2500w, 1000w more than most countertop appliances.
https://www.partselect.com/PS2368832-Frigidaire-318255511-Convection-Element-2500W.htm
Even the ones built into microwaves have it but they're a measly 900w it seems.
You should watch the video, they had that same thought
That's a big point in the video, the creator also thought that they're just glorified convection ovens. But it turns out that air fryers and convection ovens are optimized for different tasks so the food comes out differently, and there are other advantages to an air fryer too, depending on the situation. Just because they use the same technology doesn't mean they do the exact same thing.
Watch the video
it's the same general idea but they don't perform the same.
someone in the comments on youtube pointed out that many purpose built air fryers exhaust the air so the interior stays drier, where convection ovens recirculate air and hang onto humidity.