On 25 Dec, 10:33, Andy Hall wrote:
On 2007-12-25 09:45:29 +0000, said:
If you care about needlessly throwing heat out the window,
then the 220kWh (270kWh for the 4 oven) it takes to run an aga a week
may be of some concern to you.
Two points.
- The figures provided by Aga are conservatively pessimistic. I have
measured my gas consumption at the equivalent of around 700W in the
fully charged steady state. It does, of course, use more when cooking
on the top plates.
So, a "few hundred watts" is now 700W! Please make up your mind. I
choose to accept aga's official figures which I consider overly
optimistic, based on the electricity bills of two neighbours who had
electric agas installed this year. If you were being honest with
yourself you would quote your gas consumption for the average week,
but you are not. Strangely, my central heating consumption is pretty
low too when my house is up to temperature.
- Heat is not thrown out of the window any more than with any other
form of heating.
I'd agree if it were normal behaviour to leave a kW heater on
permanently, but it's not, and would be regarded as utterly foolish.
If the 425kWh of gas that a 2 oven aga uses a week were put through a
modern condensing boiler, that would be equivalent to 2.5kW heater!
Your aga will be giving off at least a kW of "waste"
power all the time it is on - which is all the time.
Incorrect. As I have said, I have measured mine in steady state at
around 700W and the heat is not wasted.
Incorrect. Your aga is cooling if it is only consuming 700W at 52%
efficiency. Please don't be so foolish as to argue this point, just
give it a moments thought instead. If you claim that an aga can be
kept at temperature by 4 lightbulbs, I will just laugh. I thought it
was "a few hundred watts" anyway.
If someone has a "normal" electric cooker I think that they are a bit
daft. These things are poorly insulated to the point that the room
temperature can rise by several degrees. Hardly surprising when 10kW
is added to the room heating. Then the window has to be opened to
dump the wasted heat.
This is so funny, hoist by your own petard!
According to Aga, a 2 oven uses 425kWh of
natural gas a week, to produce 220kWh of heat. I suppose you could
take the view that you are wasting so much energy anyway, what's the
point in wasting a bit less by fitting a more efficient burner. A 52%
efficient burner is pretty shocking considering you can get range
cookers every bit as good as an aga with condensing burners nowadays.
Aga don't make cookers with condensing burners.
Sandyford do, so do Rayburn.
Leaving that aside, you are not reading and understanding the figures
correctly.
The energy efficiency depends on the gas used and the heat released
where it is not wanted.
You are the one with the comprehension problems. An aga needs 220kWh
of heat a week according to aga. A gas aga requires 425kWh of gas a
week according to aga. The inefficiency has nothing to do with heat
being released where it's not wanted. It seems agas are just over 50%
efficient whatever the fuel (apart from electricity).
The other component would be energy released through the flue.
You are conveniently ignoring the fact that the burner is of low
efficiency.
Here's a recent article you might find enlightening:
http://money.independent.co.uk/prope...cle3133377.ece
What do you recommend for a second cooker by the way?
Nothing. It isn't necessary.
I didn't say it was necessary - it's just sensible.