Was just thinking some more on the link that Chris put on the "Christmas list suggestion" link;
http://www.hawkin.com/?PAGEID=20670&CTL_CAT_CODE=1167&STK_PROD_CODE=00570&aid=WEBG01
If this can generate hot water that quickly with minimal fuel how about a bigger version to supply the home, some sort of furnace at the base with air intakes and the "big kettle" immediately above?
Is there anything like this on the market?

Big kettles do heat homes. They are called electric central heating boilers and, along with (?worse??) elec convector heaters (on-peak) are usually fitted to new-build 'city living' blocks of flats, in exchange for a slightly lower overall u value. My colleague and I have been asked on a number of occasions to do visits to people having problems with 'Affordable Warmth', and found that they are in brand new flats, with enormous bills. Can't get my breath!

Happy New Year, all.

Nick

Nick, big kettles don't need to be electric (the link wasn't). Over the years I've built plenty of electrically heated homes with reasonable building fabric, it was never the heating that was an issue, just the hot water. The latest Part L change saw the end of electric heating (unless instant hotwater was used, but that's another story or a renewable). How does the energy source affect the u value?
That aside I was looking for a bit of thinking outside of the box, could an alternative cylinder and heat source be more efficient?

Peter Wrote:-
The latest Part L change saw the end of electric heating (unless instant hotwater was used, but that's another story or a renewable).

This confuses me, it is the first i have heard that electric heating has come to an end. Electric heaters are still available to buy and install in every form, for htg space and water. Please tell me more or send me a link.

waveydavey, it's just a case of running the SAP calcs to know that electric heating is on it's way out and that's with the current fuel factor that helps electricity compete with gas, just to get a building regs "just pass" is pretty tough unless you use a renewable or pull a few tricks such as instantaneous water heating (wish I could find a practical product!).
Then you need to look a bit further, up steps the Code for Sustainable Homes Level 3, a 25% improvement is required, currently I'm only aware of one electrical heating product that can achieve the 25% and that's a renewable (depending on your point of view), this is the ASHP, Air Source Heat Pump. (GSHP isn't really cost effective or practical on a lot of schemes)
All affordable housing from April this year needs to be level 3, add in the ambitions of local planning authorities to demand Code Levels and 20% onsite renewable energy generation (ASHP's won't achieve the later) and electric heating looks a bit wobbly.
Take the next step to Code Level 4 (44%), you might just get electric heating (not panel heaters) to work with ASHP, passivhaus standards(or better!), MVHR, Instantaneous hot water heating, but it will be a bit touch and go.
Then 2010 happens when talk says that the fuel factor will be levelled out in SAP and electricity goes toe to toe with gas(if there is any).
Electricity is currently looked at favourably in SAP because the government realises that ultimately there will only be electric heating so at present it is making life tough for the panel heaters in the hope that industry will find a super efficient electrical product.
Sorry haven't got any links, it's just a case of running SAP calcs and trying to hit the 25% and 44%, it's then very obvious that electric heating will only work with renewables.

Peter A: Apologies if I hi-jacked your thread. Yes, I appreciate my comment related not at all to the appliance you referred to. Just the words 'big kettle' and 'heating' reminded me of the absurdity of the 'quick-fix-and-then-sell-it' elec htg installations all round us. I wasn't sure how my comment on u values could have been read to suggest that the energy source affects the u value. It was the 'oh, tweak the fabric a bit and you can get away with a hopeless htg system' ethos shown in these developments that gets me. If that sort of thing is going to go on, alter BRegs so that you have to increase thermal perf MASSIVELY - to near zero-heat standards? - before you can use a less efficient system.
I'll stop rambling now.

Nick