I find that very unlikely. The average central heating boiler is rated at 23kW
(80,000 BTU/hr). 8kWh represents merely about 20 minutes use at full blast!
Most of which is needed for water heating. Modern standards of house
insulation together with double glazing as standard make a big
difference to space heating requirements. Air itself doesn't take that
much heating. And it is possible for a price to insulate so well that
waste heat from appliances can make a real contribution. Both my big
PCs on at once and my office is noticeably warmer and similarly in the
kitchen with appliance heat.
About the smallest size you can get is a nominal 50,000 BTU/hr (14.6 kW). This
one modulates between 30 and 49,800 BTU/hr (8.8 kW - 14.6 kW)
http://cgi.ebay.co.uk/BOILER-IDEAL-ICOS-HE15-CONDENSING-HEATING-GAS-B...
More so that it can get things going in a sensible amount of time. I
expect smaller units will gradually become more common as building
insulation standards are improved. It has still got to be able to
replenish a hot water tank in an acceptable period of time though
(although on demand thermostatic flash water heaters may be a better
solution).
Yes it does need some more. Being Victorian era it doesn't have cavity walls of
course.
Likewise, but my heating usage is much lower than yours. I presume
that most of this difference comes from having double glazing and a
lot of insulation in all the right places. With solid walls it is
worthwhile putting the foil backed with polystyrene behind all the
radiators (esp on any outside walls) - it makes a big difference to
losses.
Incidentally RS sell packs of stick on LCD thermometers (intended for
electronics use) which are very handy for determining how effective
additional insulation is so you can fine tune things experimentally.
Bearing in mind I'm using the place 24/7 - it's only ~ an average use of 2kW. It
represents a cost using gas of £60 pcm which is less than most homes AIUI. But
then I'm not heating every room.
And we have had sub-zero temps recently. You know, Global Warming and all that.
:~)
It is called winter. The sun is very low in the sky when it deigns to
appear at all. What is amazing is that it is so mild here in the UK at
latitude 54.5N. We have to thank the Atlantic Conveyor aka Gulf Stream
for that.
Regards,
Martin Brown