Thats nearly the worst of all options. Not only are plugin electrics the most expensive to run, but the low power output and lack of fan mean it'll need to be switched on a while before the room's used, wasting even more money.
NT
So, just run me through what you would have to do during the course of a typical day to achieve the differing temperatures required throughout the house?
Chris
Very expensive mod to zone off this one room from the rest of the house. And a normal boiler might run at reduced efficiency when just heating one small room.
The room is warmed by the central heating morning and evening when the rest of the house is in use. All that's needed is to maintain that temperature during the day. And all electric heaters are 100% efficient. Apart from a fan heater where the fan uses extra energy. ;-)
fan heaters are also 100% efficient, all the input energy ends up as heat.
Shh, don't tell mine, it runs six five zones as small as one room. No it doesn't modulate, yes it is more efficient to cycle the boiler at full power.
and where do you think that extra energy ends up?
and you can only claim the 100% efficiency if you start measuring after the 60% loss in the power stations and whatever it is in the supply network. (I learned a few days ago that our overhead HV conductors run at around 90-100C.)
Rubbish. The BIG costs are heating HUGE spaces that is unavoidable unless you are zoned to the hilt and even then running a whole house boiler to heat just one room is crappily inefficient.
Its FAR cheaper to heat a smaller space with expensive electricity than to try and modulate a whole house boiler down to do it and zone it accordingly..
Really? Yours are totally silent are they?
grid is in the 95-98% range overall.
power stations vary from 33% (coal) through OCGT (37%) to CCGT(60%+)
Nuclear about 33% but fuel usage is the least of all the costs, so who cares?
(interesting thought is a combined cycle nuclear turbine, with a compressor blowing air over white hod fuel rods driving a gas turbine, and then a steam plant,.. efficient, but probably not very radiation tight :-))
sound energy ends up as heat, too.
For this application a heat pump aircon unit will make a good deal of sense. The air handler can be high up on a wall out of the way. Running costs comparable to using gas, quick warm up as with a fan heater, plus the ability to cool in the summer for when the office get too warm from computers etc.
How precisely is it more costly to heat one room with CH, with the other rooms TRVs set to off? Where are you proposing a large amount of heat is being lost?
NT
Depends how you set it up.
NT
TRV set to off still means hot water going round pipes. Plenty of losses there. even if lagged.
The boiler will inevitably short cycle leading to hugely reduced efficiency - raw fuel chucked out the back before it fires... and heat being lost in the boiler room itself as the boiler has to heat up, then cool down, then heat up....
All about using systems in ways they were not designed to cope with.
Not to mention the fact that if the master stat is NOT in the office, the boiler will stay pumping all the time.
If you consider that there is a fixed heat loss from the system via the pipes, and a fixed amount of fuel lost when it starts up, you can see that at very low outputs its nearly ALL being lost, and almost no output.
Of course unless the pipes run through the loft the heat will end up in the house as a whole, but that is not what we are considering. We don't want to heat the house, just one room.
Its a tsndar problem of modulating heat systems: There are fixed losses. If iy wamp them by using high oputputs, they are insignificant. If you throttle back they become very significant.
Guess why a 3 liter car no matter how efficient never returns the same MPG even in a light body as a 1200 engine..the BIG engine has BIG frictional losses. Its efficient enough at 100bhp but its woeful at 30bhp.
In message , NT writes
I doubt a gas boiler keeping one rad warm gets anywhere near that.
Yes, but you're an idiot.
And what happens to the noise---- It turns into heat!
Not so. They make a noise which takes energy, and moving air around also.
It make a noise for a start.
Was talking about the end user part. In the same way as you'd measure a boiler efficiency.
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