Warning about cheap TVs currently on sale

I personally think we should ban conferences, as they waste a heck of a lot
of power.
Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"Cuzman" wrote in message
news
Simon Slavin wrote:

" I've been taking part in a conference on power use... "


I heard that there are these cheap things you can buy which end up costing
you more in the long run. I can't be specific, but I can give a
generalisation.

It's like buying a cheap pair of shoes and realizing that the soles wear
out twice as quickly as the shoes which cost 25% more. Out of six billion
people on the planet yu must be the first person to work that you
generally get what you pay for, or, more than often, less than what you
pay for.

Perhaps you should ask the government if you can run one of their recently
acquired banks, cos you've got it all sorted out.

In article ,
Agamemnon wrote:
But how efficient is heating up water and pumping it around the house,
when most of the rooms are empty, compared to direct radiation from the
back of TV. What about all the heat from the boiler that goes out of the
flue as hot air?

Very little with a modern boiler. They all use heat recovery from the flue
gasses.

--
*Being healthy is merely the slowest possible rate at which one can die.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Brian Gaff wrote:
Many modern boilers have very cool flues I notice. Thus one assumes they
must capture the heat somehow internally.

Commonly called condensing boilers. Identifiable by the plume of water
vapour from the flue on cold days. For others, obviously. ;-)

I am all electric as its considered safer for us blind folk you know,
always setting fire to ourselves aren't we?

Not quite sure how that applies to a heating system - although I can see
how it matters with a hob. A decent one with weather compensation should
only really require an on off switch.

--
*He who laughs last has just realised the joke.

Dave Plowman London SW
To e-mail, change noise into sound.

"Brian Gaff" wrote in message
m...
And as for plastic bags, I now have to buy rolls of them for me rubbish
whereas before I just used the supermarket ones.
bah humbug.

Yes, and the ones you buy contain far more plastic (because they are a
heavier gauge) and thus create more landfill.

Bill

And if I can't have a cheep power hungry TV heating up the room then I will
have to pay more for the central hearting.

Only when the weather is cold! On a hot summer night, you would have
to put a fan on or turn the air conditioning system on to cool down
this unwanted heat generated.


Bloody environmentalist morons.

You have only thought about one part of the year, and not the rest of
it! Who is short-sighted now?


It's bad enough they had to phase out 100W light bulbs. How am I supposed to
stay warm while reading in bed?

Blankets and pyjamas? Or how about not reading in bed? What is wrong
with reading in another part of the house that is warm anyway, eg the
kitchen or living room?

Don't these idiots ever think.

Are you referring to yourself?

How much
energy and damage to the atmosphere do those useless florescent energy
efficient light bulbs cost to manufacture compared to cheep 100W ones.

I have never heard of a lightbulb that makes bird noises!!

If
the heat for the house doesn't come from them then something else will have
to provide it,

This is not always so! It could be warm out anyway!

John

In article ,
Bob Latham wrote:
In article ,
Dave Plowman (News) wrote:
In article , Brian Gaff
wrote:
Many modern boilers have very cool flues I notice. Thus one assumes
they must capture the heat somehow internally.

Commonly called condensing boilers. Identifiable by the plume of water
vapour from the flue on cold days. For others, obviously. ;-)

From what I understand and I'm not an expert, there is a problem with
condensing boilers though. It seems that they use two heat exchangers,
the second of which works in the normal way. The first one however is
used to heat the returning (coldest) water before it enters the main
part of the boiler.

Older designs - which were actually modifications from non condensing -
could but newer ones have a purpose built heat exchanger. Although the
principle is the same.

The condensing action recovers heat (latent) that is used to change a
liquid into a gas and hence returns *mostly* steam into water. The
problem though is that this only happens whilst the returning water is
cold enough. When the water warms up, the first heat exchanger is too
hot to condense the steam in the flue and the condensing action stops as
does a lot of the heat recovery.

A decent modern boiler will modulate the flame and pump speed to maintain
the optimum. With mine this means slightly slower warm up times compared
to the old non condensing boiler. Although I could over-ride this if
needed to get faster warm up by allowing the boiler to go into non
condensing mode.

To improve the situation, some people seem to advocate fitting over sized
radiators in every room, the idea being to get the returning water
temperature lower so as to maintain condensing action longer.

Yes. If the system was undersized so the boiler can rarely get into
condensing mode this is so. But most were designed to cope with
temperatures well below the winter norm so can operate in condensing mode
for most of the time. Obviously changing otherwise ok rads for larger ones
is expensive - so you'd need to work out if the investment was worth it in
fuel savings. I did and it wasn't.

What I would love to know is what is the real world improvement of a
condensing boiler over just a new boiler without changing the radiators.

Here somewhere over 20% in gas usage. Of course the rise in gas prices
means I'm actually paying more than this time last year - I installed the
new boiler last spring. The old boiler was a balanced flue type with pilot
light mounted internally where the waste heat wasn't wasted - at least in
the winter. With up to date controls - programmable thermostat for the
main living area and TRVs elsewhere. The new boiler is weather
compensated. But the hot water remains as was - a storage system.

Oh, and I think these boilers have to have fans in the flue because you
can no longer rely on hot air rising to remove the fumes.

Fan assisted flues came in long before condensing boilers. They allow a
longer flue than the older balanced flue terminals.

--
*Someday, we'll look back on this, laugh nervously and change the subject

Dave Plowman London SW
To e-mail, change noise into sound.

"Agamemnon" wrote in message
. uk...

"Richard Tobin" wrote in message
...
In article ,
Agamemnon wrote:

And if I can't have a cheep power hungry TV heating up the room then I
will
have to pay more for the central hearting.

Electricity: 11.518 p/kWh
Gas: 3.398 p/kWh

But how efficient is heating up water and pumping it around the house,
when
most of the rooms are empty, compared to direct radiation from the back of
TV. What about all the heat from the boiler that goes out of the flue as
hot
air?


There are several kinds of radiation that's emitted from televisions, not
all of it is heat.
Using televisions as heaters would not be easy to do as you would have to
quote consumption & picture quality & cost... rough to mix all 3

In article ,
mr deo wrote:

There are several kinds of radiation that's emitted from televisions, not
all of it is heat.

It's all heat sooner or later. Sound, light, x-rays - they all just
heat something up. Some may escape - if your neighbours can see or
hear your TV, then you're heating their house up too.

-- Richard
--
Please remember to mention me / in tapes you leave behind.

Agamemnon wrote:

"Richard Tobin" wrote in message
...
In article ,
Agamemnon wrote:

And if I can't have a cheep power hungry TV heating up the room then I
will
have to pay more for the central hearting.

Electricity: 11.518 p/kWh
Gas: 3.398 p/kWh

But how efficient is heating up water and pumping it around the house, when
most of the rooms are empty, compared to direct radiation from the back of

With proper controls (thermostatic rad valves, appropriate zoning, and
boiler interlock (i.e. programmable thermostat) it is actually quite
efficent.

TV. What about all the heat from the boiler that goes out of the flue as
hot
air?

a modern boiler will loose well under 10% or the energy input out of the
flue.

Your TV may be nearly 100% efficient at turning electricity into heat,
but electricity is a secondary energy source, with less than 60%
efficiency when you include the generation and distribution elements.

So in general, the only time that using the TV as a heat source is
preferable or at least equal to other heating methods, is when your
whole heating system is electric (resistive) only.

(one also needs to factor in that during some of the year the heat
contribution from the TV is unwelcome)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Bob Latham wrote:

From what I understand and I'm not an expert, there is a problem with
condensing boilers though. It seems that they use two heat exchangers, the
second of which works in the normal way. The first one however is used to
heat the returning (coldest) water before it enters the main part of the
boiler.

The ones with additional HEs were basically kludges to modify existing
designs. Purpose designed condensers use one larger (and much more
efficient) HE. (and make it from a material that does not mind getting
wet - many of the kludge designs still used cast iron primary HEs that
promptly rotted away quickly in the presence of mildly acidic condensate
water)

The condensing action recovers heat (latent) that is used to change a
liquid into a gas and hence returns *mostly* steam into water. The problem

Yup, the liquid in question being the water manufactured when oxidising
a hydro-carbon...

though is that this only happens whilst the returning water is cold
enough. When the water warms up, the first heat exchanger is too hot to
condense the steam in the flue and the condensing action stops as does a
lot of the heat recovery.

There is a rise in efficiency when the return temp falls below the dew
point of the condensate (approx 54 deg C). However the larger more
efficient HE recovers more heat at all temperatures. So there is always
nett gain over boilers that used to be designed to have a very low
risk of condensing.

You also need to factor in that most boilers are modulating these days
and have reasonably sophisticated control systems. This will ensure that
the boiler is kept in its more efficient operating conditions for longer
by attempting to match the heat input from the boiler to the heat loss
of the building. This also improves comfort with more consistent
temperature control and less overshoot.

To improve the situation, some people seem to advocate fitting over sized
radiators in every room, the idea being to get the returning water
temperature lower so as to maintain condensing action longer.

This is only really worth doing if the existing rads were bordering on
the small side. Even then it will not make any difference for the vast
bulk of the year. However with the smaller rads, the efficiency might
fall on the very coldest days since the boiler will need to up its flow
temperature in order to get the house warm enough.

What I would love to know is what is the real world improvement of a
condensing boiler over just a new boiler without changing the radiators.

For all but 10 - 20 days a year, probably about what it says on the tin.
The best non condenser is perhaps 80% - 85% efficient, and current
boilers will be in the 91% to 96% range.

Having said that, the environmental benefit of ripping and replacing a
working system before it is required just to get better boiler
efficiency is doubtful at best.

Oh, and I think these boilers have to have fans in the flue because you
can no longer rely on hot air rising to remove the fumes.

All modern boilers use premix burners and fanned flues - this applies to
condensers and the older models as well. In fact there is little
difference in complexity between a modern electronic control boiler and
its condensing evolution.

The non fan assisted flue models with natural draft flues are
significantly less efficient - often in the 50 - 65% range.

The history of designs is charted he

http://wiki.diyfaq.org.uk/index.php?...iler_Evolution


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/