Induction hob

[Oliver90owner]

Thanks Nowty. Yes, that fan is not there just to rotate aimlessly. It is there to remove the energy dissipated by the microwave magnetron, as heat - wasted heat.

It really is an open and shut case - unless some dim user fills the kettle with far more water than needed. Modern electric kettles use an element in the base of the kettle, not one some distance from the bottom of the vessel. Most are also made of plastic, mainly, meaning reasonable insulating properties along with lowish heat capacity.

A simple search from the ‘net would reveal the following, if one searches:

The modern magnetron is a fairly efficient device. In a microwave oven, for instance, a 1.1-kilowatt input will generally create about 700 watts of microwave power, an efficiency of around 65%. (The high-voltage and the properties of the cathode determine the power of a magnetron.)

Losing about a third of the input power as heat (plus the fan and rotating table power) makes it a non-starter for efficiently heating plain water.

[Joeboy]

A quick update on the induction hob. Been out with SWMBO looking at various hobs and she quite fancied a ceramic hob until i explained the response time in comparison to gas. She then went off on her own tangent rip roaring through the cupboards and had me test all the pans with a magnet. Turns out we have a single frying pan and three of Tefal induction pans that I spotted a year or so ago for a fiver. The Neff twin plate induction hob SWMBO brought home a few years ago as untested FOC.

She rearranged the worksurfaces in the kitchen and we are now a twin induction hob and 5 rig gas burner couple. Add in the other twin and also single element portable cookers we have and we are 10 rings cooking capable and sorted for Christmas!

A decent compromise, she wins, keeps all her pots and pans she likes and i get to live another day while forcing any use of gas further and further away. Total cost to engage with the world of induction cooking? Fiver!





We can run like this for a while and then we'll see if she fancies a countersunk twin unit installed but i'll wait for her to come to me on that one.

Edit- did a quick 500ml water to boil test to see power consumption and speed.
Induction hob did it in 2min 40s for 0.07kWh
Kettle did it in 1min 40s for 0.06kWh

[nowty]

Edit- did a quick 500ml water to boil test to see power consumption and speed.
Induction hob did it in 2min 40s for 0.07kWh
Kettle did it in 1min 40s for 0.06kWh

You'll have to re-run that test for the gas hob.

Bit of number crunching to do though.

[Joeboy]

Hold the boat, monster Pyrex pot is magnetic too, what a time I'm having!

[Joeboy]

Edit- did a quick 500ml water to boil test to see power consumption and speed.
Induction hob did it in 2min 40s for 0.07kWh
Kettle did it in 1min 40s for 0.06kWh

You'll have to re-run that test for the gas hob.

Bit of number crunching do though.

Can't. It would break the 'no gas' run that we are on.

[nowty]

Edit- did a quick 500ml water to boil test to see power consumption and speed.
Induction hob did it in 2min 40s for 0.07kWh
Kettle did it in 1min 40s for 0.06kWh

You'll have to re-run that test for the gas hob.

Bit of number crunching do though.

Can't. It would break the 'no gas' run that we are on.

I'll re-run the tests myself and even include a microwave. I can still do it within my 1kWh per day of gas allowance .

EDIT - Actually I cannot do the electrical ones very easily as I have not got a power meter and there are too many loads going on simultaneously but I will do the 500ml of water on the gas hob using my gas smart meter. And not to waste it will make several cups of tea / coffee for my visitors.

[Joeboy]

You'll have to re-run that test for the gas hob.

Bit of number crunching do though.

Can't. It would break the 'no gas' run that we are on.

I'll re-run the tests myself and even include a microwave. I can still do it within my 1kWh per day of gas allowance .

In the last 84 days we have used 67kWh of gas and 95% of that can be laid at my own door for wrong setup of timings and having to run hot water or heating a couple of times. 0.79kWh per day, cooking itself has been pretty much knocked out the park for gas.

I'll be interested to see your results Nowty. I did my wee test as i read two claims online that an induction hob could beat a kettle for boiling water. I have no idea of the age of this hob and maybe tech has moved on. Nonetheless, the kettle fairly skelped the induction hob in that test. In saying that i'd look daft trying to make veg soup in the kettle!

[Joeboy]

Are your visitors onside with tests during visits?

Our last gas use of any kind was 10th April (a sliver of gas). We have used a total of 650kWh gas since 1st Jan. I am really enjoying closing out the hopefully final gaps for non essential gas use. A sense of undeniable empowerment in this whole process.

To put the 650kWh since 1st Jan 22 into perspective for those new to the forum, back in Jan 18 we used 4,256kWh in that single month alone. Jan to May in 2018 was 15,366kWh...

That's a 95.77% reduction in gas use on a 5 month comparison. I don't even know what to say about that.

SWMBO has become so enthused about this lifestyle it's amazing, I am truly fortunate.

[nowty]

I'll be interested to see your results Nowty. I did my wee test as i read two claims online that an induction hob could beat a kettle for boiling water. I have no idea of the age of this hob and maybe tech has moved on. Nonetheless, the kettle fairly skelped the induction hob in that test. In saying that i'd look daft trying to make veg soup in the kettle!

(nowtyexperiment for searching)
The results are in and there was someone who I cannot remember or even the thread, who recently said the kettle wins hands down and I think they are correct. However you cant cook in a kettle.

I was surprised how poorly the induction hob fared but it could be with my cookware, they are aluminium with a composite steel base, maybe not as good as having an all steel pan. Also the pan did not fully cover the active heating area.

Similar deal as Joeboy, 500ml of cold tap water heating test.

Gas hob, pan 3/4 full on medium size burner – 6 min 10 sec, 0.019m3 gas or 0.21 kWh
Same pan on 2kW induction hob – 5 min 20 sec, 0.18 kWh (EDIT - probably over estimated power draw because of small pan)
Full glass jug 1.6kW microwave – 5 min 10 secs, 0.14 kWh
2kW glass kettle – 1 min 50 secs, 0.061 kWh

And just for fun and nostalgia (for folk of st elsewhere), a picture of the same kettle boiling 1000ml of water after 15 mins directly connected to 2 x 335w solar panels. Don't do this at home folks, DC and all that.

[Joeboy]

I'll be interested to see your results Nowty. I did my wee test as i read two claims online that an induction hob could beat a kettle for boiling water. I have no idea of the age of this hob and maybe tech has moved on. Nonetheless, the kettle fairly skelped the induction hob in that test. In saying that i'd look daft trying to make veg soup in the kettle!

The results are in and there was someone who I cannot remember or even the thread, who recently said the kettle wins hands down and I think they are correct. However you cant cook in a kettle.

I was surprised how poorly the induction hob fared but it could be with my cookware, they are aluminium with a composite steel base, maybe not as good as having an all steel pan. Also the pan did not fully cover the active heating area.

Similar deal as Joeboy, 500ml of cold tap water heating test.

Gas hob, pan 3/4 full on medium size burner – 6 min 10 sec, 0.019m3 gas or 0.21 kWh
Same pan on 2kW induction hob – 5 min 20 sec, 0.18 kWh
Full glass jug 1.6kW microwave – 5 min 10 secs, 0.14 kWh
2kW glass kettle – 1 min 50 secs, 0.061 kWh

And just for fun and nostalgia (for folk of st elsewhere), a picture of the same kettle boiling 1000ml of water after 15 mins directly connected to 2 x 335w solar panels. Don't do this at home folks, DC and all that.

We match on kettles, also surprised at induction hob reading. I used a Tefal pan covering full induction area. Hopefully someone else will try the test(s). Liking the DC kettle direct from PV!
The gas is so far off the pace.