Author Topic: Induction Hobs and technology  (Read 3207 times)

ancientone

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Induction Hobs and technology
« on: November 13, 2010, 04:23:53 PM »
The induction hob is  easy to use,very efficient,safe(ref old people and children) yet there seems to be very little in the way of promotion of this technology. One major manufacturer states,in their catalogue,that it is faster than gas. It's much cleaner also virtually noiseless. Could this technology be used in the production of central heating boilers? Cleaner,safer,quieter.No chance of Carbon Monoxide. With the future production of electricity likely to be Wind,Hydro,Solar or Nuclear it would have a cleaner energy source. Some might generate their own.(You can't have your own gas rig). Is this the way forward or is there major problems?

Ancientone

Paul Marriott

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Re: Induction Hobs and technology
« Reply #1 on: November 22, 2010, 01:22:12 PM »
Induction stove technology cannot be used for making "more efficient" boilers. At best, all electric resistance heaters are 100% efficient. Induction stovetops only appear more efficient than regular electric rings because they are  moreeffective at transferring the heat to the pan, not because of greater efficiency. The same advantage applies over gas stovetops too.

The only way to get electric heating that is more efficient than straight resistance heating is to use a heatpump, where the apparent efficiency is multiplied by the coefficient of performance. So if your heatpump has a COP of 2.5, then for every 1kW of electrical energy you put in, you will get 2.5kW of heat out - with the "extra" 1.5kW coming from the air (in the case of an ASHP) or the ground (in the case of a GSHP).

Paul.

Dave Howorth

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Re: Induction Hobs and technology
« Reply #2 on: November 24, 2010, 10:04:10 PM »
The only way to get electric heating that is more efficient than straight resistance heating is to use a heatpump, where the apparent efficiency is multiplied by the coefficient of performance. So if your heatpump has a COP of 2.5, then for every 1kW of electrical energy you put in, you will get 2.5kW of heat out - with the "extra" 1.5kW coming from the air (in the case of an ASHP) or the ground (in the case of a GSHP).

Here's some live real-time heatpump data: http://www.elisanet.fi/sanyoco2log/

Of course, the Finns have been using heat pumps a lot more than we have, so they've no doubt ironed out the teething problems. ::)

ancientone

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Re: Induction Hobs and technology
« Reply #3 on: January 11, 2011, 04:40:54 PM »
Induction hobs do not transfer heat to a pan. There is no heating element. The pan is the original generator of cooking heat.The hob induces the pan to create heat using magnetic fields.Without a pan there cannot be heat.It is not the same,nor can it be compared to gas or other electric hobs. Refer The Owlcroft Company.There may be a design for an induction boiler possibly, Korean.

Mark Bennett

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Re: Induction Hobs and technology
« Reply #4 on: January 11, 2011, 06:31:32 PM »
Induction hobs do not transfer heat to a pan. There is no heating element. The pan is the original generator of cooking heat.The hob induces the pan to create heat using magnetic fields.Without a pan there cannot be heat.It is not the same,nor can it be compared to gas or other electric hobs.

Much of this is true, but it is certainly possible to compare one form of heating food with another, e.g. microwaves, hobs etc.

There may be a design for an induction boiler possibly, Korean.

But what would be the point? An immersion heater is already 100% efficient, how would an induction heater improve on this?

Induction hobs are relatively expensive technology, so any boiler using the technology (although I can't quite envisage how you would do it - induct currents in the shell of the cylinder, or in a lump of iron inside the cylinder?) would also be expensive and couldn't be much better.

fostertom

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Re: Induction Hobs and technology
« Reply #5 on: January 25, 2011, 02:42:20 PM »
In principle, can induction hobs be efficient? Certainly, they don't waste much heat on heating the room, but how much of that advantage is lost in the electronics?

Paul Marriott

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Re: Induction Hobs and technology
« Reply #6 on: January 26, 2011, 08:41:24 PM »
Induction hobs have an advantage over gas and regular electric rings because they couple more heat into the pan where it's needed. So even though some is lost in the electronics, this is less than the amount that's lost be a regular electric ring heating the air rather than the pan - same thing for gas too which has even bigger losses than electric (though costs less to run in the UK per kWh). The electronics don't actually lose much either - similar to a switching mode power supply so efficiencies are in the 90% range.

Paul

fostertom

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Re: Induction Hobs and technology
« Reply #7 on: January 27, 2011, 01:06:13 PM »
Good news. Any progress with the insulated pans that were being developed - the radiation passing thro the insulation, heating the iron pan and little being lost outward by re-radiation/conduction/convection?

Beyond that, looking forward to pan lids plumbed into the MHRV, so heat lost in steam etc gets captured.