Heating house with induction

[msmiha]

Hi!

So I've got this idea to heat the house with the induction current. Same principle can be seen in the induction cookers. The idea is to build a "big induction cooker" that could heat a house if it would be mounted on central heating system. I've google up if such a system is already on the market, but surprisingly there was not a lot of hits. Why is that? Is this a stupid idea? Would efficiency of such a system be poor? However I have found with similar idea. So what do you thing could this be done? Would this be a efficient way to heat the house in winter?

 

[andre_luis]

As far as I can see, the biggest drawback of using an electromagnetic based heater is its intrinsic ability to spread certain level of EMI emissions, however it seems advantageous in the case where you don’t want to put the heater in direct contact with the water, like a portable system ( although this can be done with heat exchangers ).

 

[AhmedGalal]

I think it's very HAMFUL "Cancer"

 

[brushhead]

In order to heat a house, you're probably talking around 15kW. That's an awful lot of of electricity compared to the same energy consumption of old fashioned gas fired central heating.

 

[andre_luis]

I think it's very HAMFUL "Cancer"

I guess he's referring not to cook the whole house and people within :razz:, but the water inside a pipe or boiler at the basement, replacing the traditional heating system. Anyway, I doubt it could be done in any frequency below GHz, which would flood the surrounding with noise impeding communication in mobile telephony.

 

[brushhead]

No not that high, you would only have to run probably to 200kHz, depending on the size of the susceptor, ie the metal (pipe?)you're heating up. I do have experience in induction heating. Losses would make it was impractical.

 

[andre_luis]

According to the Figure1 at the following link, we can see that an oven operating at 200KHz would be very inneficient: **broken link removed**

Anyway, whatever the frequency adopted, answering the original question, I believe it is not an advisable idea to do an induction-based heating system.

 

[FvM]

The initial post misses any hint how induction heating should be used to heat a house, in so far I don't hear a clear question.

The specific point of induction cookers is that it can effectively heat cooking pots and frying pans made of ferromagnetic material (steel) by eddy currents. I don't see a similar point with residential heating. So what's the discussion all about?

 

[msmiha]

The initial post misses any hint how induction heating should be used to heat a house, in so far I don't hear a clear question.

The specific point of induction cookers is that it can effectively heat cooking pots and frying pans made of ferromagnetic material (steel) by eddy currents. I don't see a similar point with residential heating. So what's the discussion all about?

Hi FvM!

Why not? My idea is to use a steal heat exchanger (steel tubing with chambers) through which would flow water. Around that steel tubing I would wrapped coil and heat everything up. This heat exchanger would be connected to central heating system. So basically eddy current would heat that heat exchanger and this would heat a water that is running through it.

 

[FvM]

This clarifies your idea.

But I don't see any advantage over a conventional resistive heater, but relevant losses (at least 2 - 3 percent) by the necessary inverter circuit and higher price.

The smallest possible AC heater has the resistance wire coils directly immersed in the water (proper earthing of the surrounding tube/vessel required), used in some tankless instant water heater systems. More ruggedized and with electrical isolation, industry standard stainless steel heating elements.

 

[AhmedGalal]

Thanks for declaration

 

[msmiha]

This means I wont gain anything against traditionally resistant heating? This explains why there aren't many systems in use for this purposes. However I thought there would take far less time to heat water with a induction, than with traditionally resistant heating (like with the induction cooking plate). Consequently, I thought there will be better efficiency ratio, compared to traditional resistant heaters. But it looks like I was wrong.

 

[dick_freebird]

For inductive heating, you have generally a close-coupled
magnetic field (workpiece inside solenoid winding, or for
cooking, a flat coil with the susceptor directly above).
That works OK. But now you want to heat very remote
features (which would need to be placed, and ensured
that convection is as desired) which will be poorly
coupled. Direct electric heat is wasteful, using high
grade energy to do a low grade job, and doing this with
HF losses on top makes even less economic sense.

Then there's the question of how the refrigerator's
steel skin will like being inductively heated, how the
various electronics will see that high power EM field
and all that - which maybe a one-off hobby project
could deal with, but is liable to be a hurt waiting to
happen when you expose the concept to the wider
universe of human ignorance and home furnishing
variation.

Forced air probably still wins over forced ether.

 

[mtwieg]

This means I wont gain anything against traditionally resistant heating?

Not if you just want to heat a pipe carrying water. The electrical efficiency of a standard heating element is basically 100% already. The thermodynamic efficiency is based on how good your insulation is.

Inductive cooking is nice because there is only heat when the cookware (or any large metal object) is near the coil, which makes it safer than gas or heating elements which might start a fire if you leave them on by mistake.