Author Topic: What type of hob do I have?  (Read 1282 times)

What type of hob do I have?
« on: May 17, 2020, 07:45:10 pm »
When I look at induction hobs (here) or ceramic hobs (here), they look the same to me and the same as ours - black glass with grey markings and touch-sensitive glass for buttons, more like a mobile phone than a cooker of old.

What we are trying to work out is whether we can use enamel pans on our Whirlpool electric hob which has one halogen zone and 3 electric zones. Can you help?

PS. When I tried asking search engines whether I can use enamel pans on an electric hob I get this suggested:

Kim

  • Timelord
Re: What type of hob do I have?
« Reply #1 on: May 17, 2020, 07:46:56 pm »
In the absence of a pan, an induction hob won't get hot.
Careful, Kim. Your sarcasm's showing...

Re: What type of hob do I have?
« Reply #2 on: May 17, 2020, 07:54:45 pm »
Aha, ours does, so that makes it a ceramic hob, I guess.

citoyen

  • Cat 6 Racer
Re: What type of hob do I have?
« Reply #3 on: May 17, 2020, 08:16:42 pm »
In the absence of a pan, an induction hob won't get hot.

And even with a pan present, it won't get hot if it's not the right type of pan.

Re: What type of hob do I have?
« Reply #4 on: May 17, 2020, 08:49:09 pm »
That is even more helpful, citoyen, as I had heard something about that and that is why I was trying to figure out whether enamel pans would work and be safe. That is the problem of having some but insufficient knowledge. Thank you.

Re: What type of hob do I have?
« Reply #5 on: May 17, 2020, 08:55:21 pm »
The easy way to tell the difference is to turn the hob on and see if gets hot.

Ceramic hobs are halogen rings under a glass plate usually. The halogen ring pumps out infrared radiation, the rings heat up to up to up to 700 deg C.

Induction hobs do not use radiated heat at all they stay cold (apart from any heat that is re re- re-radiated from the pan into the glass top). Instead an oscillating magnetic field induces eddy current in ferrous pans . The pans themselves produce the heat rather than the hob getting hot. Its quicker and more controllable since like gas when you tun it down or switch it off there is immediately less or no heat input to the pan. The way it works means you have to use ferrous pans or they wont heat up. Enamelled cast iron works fine.
I think you'll find it's a bit more complicated than that.

citoyen

  • Cat 6 Racer
Re: What type of hob do I have?
« Reply #6 on: May 18, 2020, 09:06:27 am »
I was trying to figure out whether enamel pans would work and be safe.

If you don't have an induction hob yet, the easiest way to tell if a pan will work on one is to test it with a magnet.

I'm not aware of any safety concerns with induction, but I dare say there are some internet cranks who will tell you the magnetic radiation is deadly in the same way that 5G masts and vaccinations are deadly.

T42

  • Old fool in a hurry
Re: What type of hob do I have?
« Reply #7 on: May 18, 2020, 09:16:25 am »
Natch an induction hob will heat up by conduction from the pan.
I've dusted all those old bottles and set them up straight.

Re: What type of hob do I have?
« Reply #8 on: May 18, 2020, 10:23:00 am »
Natch an induction hob will heat up by conduction from the pan.

Indeed but not nearly as much as hob that's heating a pan by radiated heat.
I think you'll find it's a bit more complicated than that.

Re: What type of hob do I have?
« Reply #9 on: May 18, 2020, 07:49:08 pm »
I think that’s a bog standard electric hob, not induction nor ceramic.
We are making a New World (Paul Nash, 1918)

Cudzoziemiec

  • Waking up now, put the kettle on!
Re: What type of hob do I have?
« Reply #10 on: May 18, 2020, 08:05:04 pm »
So if your pans have got a layer of aluminium inside the base, which ISTR ours have for claimed better heat transfer, that will actually make them less efficient on an induction hob? Similarly posh copper ones. Not that it matters to us, our hob is ye olde gas.
Days become simply the spaces between dreams, spaces between the shifting floors of time...

citoyen

  • Cat 6 Racer
Re: What type of hob do I have?
« Reply #11 on: May 19, 2020, 08:32:42 am »
So if your pans have got a layer of aluminium inside the base, which ISTR ours have for claimed better heat transfer, that will actually make them less efficient on an induction hob?

Not sure. I'm thinking probably not because of the way it works - only the steel bits of the pan will absorb energy from the hob, and the aluminium bits will absorb energy from the steel bits. But the inner workings of induction hobs are way beyond the limits of my scientific knowledge.

DaT

Re: What type of hob do I have?
« Reply #12 on: May 19, 2020, 08:39:38 am »
I’m a chef so I’ve cooked on gas my whole life. Had electric at home years ago and hated it so always stayed with gas. We bought an induction hob recently and it’s fantastic, even better than gas. They’re a bit pricy but I recommend them every time someone says there looking for a new cooker now.

Re: What type of hob do I have?
« Reply #13 on: May 19, 2020, 08:42:29 am »
If our induction hob cooker ever packs up (its 10 years old now) I would buy another induction one its been great. The only change I would make is to see if I could get one with rotary power controls rather than touch ones embedded in the glass as that would be a bit less fumbly to control.
I think you'll find it's a bit more complicated than that.

Re: What type of hob do I have?
« Reply #14 on: May 19, 2020, 03:00:51 pm »
We have an induction hob and it has taken over from the microwave for some uses, like heating cooked tomatoes and baked beans, as it is so much faster.

The single gas ring that is part of it gets very occasional use, for instance when heating gravy in a baking tin that is too thin for the induction rings.

As others have said, there is no way we are going back to anything else.
Quote from: Kim
Paging Diver300.  Diver300 to the GSM Trimphone, please...

citoyen

  • Cat 6 Racer
Re: What type of hob do I have?
« Reply #15 on: May 19, 2020, 03:38:14 pm »
Same here. We're on our second induction hob and wouldn't have any other kind.

But to go back to the actual question road runner asked... there's no reason not to use enamel pans on a ceramic hob.

Re: What type of hob do I have?
« Reply #16 on: May 19, 2020, 07:17:06 pm »
Enamel pans work on every heat source as they are all cast iron aren't they? Wobbly bottoms wont conduct as well as flat based pans do.

ian

  • fatuously disingenuous
    • The Suburban Survival Guide
Re: What type of hob do I have?
« Reply #17 on: May 19, 2020, 07:48:44 pm »
So if your pans have got a layer of aluminium inside the base, which ISTR ours have for claimed better heat transfer, that will actually make them less efficient on an induction hob?

Not sure. I'm thinking probably not because of the way it works - only the steel bits of the pan will absorb energy from the hob, and the aluminium bits will absorb energy from the steel bits. But the inner workings of induction hobs are way beyond the limits of my scientific knowledge.

They're quite simple, the hob is basically a copper coil with an a/c current passing through it that induces a surface current in the base of ferrous (steel, iron) cookware (think of transformers, not those, the buzzy ones that 'may cause death'). This induced current, owing to resistance, generates heat. It doesn't work very well with non-magnetic materials like aluminium, but these materials conduct heat very well from the ferrous base of the pan (far better than the ferrous material). The ferrous material should be thin, it's a surface effect. Big hunks of iron won't be as effectively or efficiently heated.

Pans generally need a flat bottom because of the inverse square law (you were paying attention in physics, weren't you? admittedly I switched off soon after) so you can't just plonk a wok on them.

I don't have one, not sure why, other than my inner caveman likes fire and it wouldn't be me if I didn't periodically set fire to a tea towel.
!nataS pihsroW

Re: What type of hob do I have?
« Reply #18 on: May 19, 2020, 08:03:39 pm »
The ferrous material should be thin, it's a surface effect. Big hunks of iron won't be as effectively or efficiently heated.

Are you saying that Le Creuset and induction hobs are not the best working partners?

Cudzoziemiec

  • Waking up now, put the kettle on!
Re: What type of hob do I have?
« Reply #19 on: May 19, 2020, 08:38:25 pm »
I don't have one, not sure why, other than my inner caveman likes fire and it wouldn't be me if I didn't periodically set fire to a tea towel.
When I were a PSO, I – it might have been one of my flatmates but I'm claiming the glory anyway – set fire to the entire hob. When I say hob, it was more the layer of congealed fat and dried pasta than the actual hob itself, but still...
Days become simply the spaces between dreams, spaces between the shifting floors of time...

fuaran

  • rothair gasta
Re: What type of hob do I have?
« Reply #20 on: May 19, 2020, 08:52:28 pm »
The ferrous material should be thin, it's a surface effect. Big hunks of iron won't be as effectively or efficiently heated.

Are you saying that Le Creuset and induction hobs are not the best working partners?
Le Creuset pans work great on an induction hob.
Just don't drop the pan on a glass hob. It may crack the hob (though the pan will be undamaged).

Kim

  • Timelord
Re: What type of hob do I have?
« Reply #21 on: May 19, 2020, 09:07:57 pm »
Pans generally need a flat bottom because of the inverse square law (you were paying attention in physics, weren't you? admittedly I switched off soon after) so you can't just plonk a wok on them.

I was, sadly, paying attention in physics.  It's an inverse cube law for magnetic fields (unless you use single-ended magnets, I suppose).

This is why your laptop doesn't get its had drive reformatted when you take it on the tube, and why your wireless bike computer doesn't work properly.
Careful, Kim. Your sarcasm's showing...

Cudzoziemiec

  • Waking up now, put the kettle on!
Re: What type of hob do I have?
« Reply #22 on: May 19, 2020, 09:12:58 pm »
The only reason my wireless bike computer didn't work properly was because I didn't usually remember to press the button to wake it up. But it would have been safe to drop it on an induction hob, so that's okay. Unless the hob was already hot from something else.
Days become simply the spaces between dreams, spaces between the shifting floors of time...

ian

  • fatuously disingenuous
    • The Suburban Survival Guide
Re: What type of hob do I have?
« Reply #23 on: May 19, 2020, 09:30:59 pm »
Pans generally need a flat bottom because of the inverse square law (you were paying attention in physics, weren't you? admittedly I switched off soon after) so you can't just plonk a wok on them.

I was, sadly, paying attention in physics.  It's an inverse cube law for magnetic fields (unless you use single-ended magnets, I suppose).

This is why your laptop doesn't get its had drive reformatted when you take it on the tube, and why your wireless bike computer doesn't work properly.

Too many dimensions for me, I never did good with maths. Anyway, field strength falls off rapidly, which is also why 5G transmitters are very unlikely to bake our heads.
!nataS pihsroW

citoyen

  • Cat 6 Racer
Re: What type of hob do I have?
« Reply #24 on: May 20, 2020, 08:48:31 am »
So if your pans have got a layer of aluminium inside the base, which ISTR ours have for claimed better heat transfer, that will actually make them less efficient on an induction hob?

It doesn't work very well with non-magnetic materials like aluminium, but these materials conduct heat very well from the ferrous base of the pan (far better than the ferrous material). The ferrous material should be thin, it's a surface effect. Big hunks of iron won't be as effectively or efficiently heated.

So to answer Cudzo's question, such pans will actually be more efficient. Which correlates with my experience - we have some such pans and they do seem to heat up quicker than the Le Creuset ones. Not that this is in any way a scientific observation.

Quote
you were paying attention in physics, weren't you?

I wasn't even physically present at quite a few physics lessons, never mind mentally present. Somehow scraped a B at GCSE and that was me done with science for ever more. Which is a source of some regret, I admit.