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  #41   Report Post  
Posted to uk.d-i-y
Doctor Drivel
 
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Default Combi boiler - condensing - or not?


"Tony Bryer" wrote in message
...
On Fri, 17 Mar 2006 15:54:23 -0000 Doctor Drivel wrote :
Chav, you really are a dumbo. Here is the GasTec report:
http://www.zenexenergy.com/downloads/Final%20GasTec%20report%20for%20Zenex.pdf


Which says that during the summer season you can expect to cut your
DHW energy usage by 12%. On a modern house DHW is responsible for about
one third of energy use and most of this will be during the heating
season (greater part of year and colder water coming in).

"Added to this figure should be the instantaneous saving of ~2.47% that
this achieved whilst the boiler is operational in DHW mode. The total
saving is thus projected to be ~(38+2.47) % ie fractionally in excess
of 40%.


It is a thermal store of condensate. In CH running the wasted heat heats the
store of water to ~50-60C. As they said in most cases of small DHW
draw-offs the vast majority of heat will come from this small store. So, in
winter much of the wasted CH heat is reclaimed, and it is then used for DHW
use.

There are clear gain. When makers are attempting to grap the extra 1
litre/min of the competition, this is a real quantum jump in efficiency.

With some clever piping and controls this could also be used to boost UFH as
well.

  #42   Report Post  
Posted to uk.d-i-y
Tim Downie
 
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Default Combi boiler - condensing - or not?

Andy Hall wrote:

For heating running for a third of the day, the implication would be
of 5.5kWh per day. However, it's unlikely that all of the heat could
be recovered - perhaps 30% - so we are talking about say 2kWh/day.


Why only 30%? Genuine question. If you run gases in opposite directions
you always have a thermal gradient between incoming and outgoing gas which
makes countercurrent heat exchangers potentially very effective.

This works out to about £15/year.


Unless more than 30% is attainable.

Of course, this is estimation, but I think it's reasonable
approximation within half an order of magnitude

There are other places to obtain a better ROI.


Not if you can knock one up for £15. ;-) Bit of plastic drain pipe and a SS
exhaust cutoff from the local Quikfit.

Tim


  #43   Report Post  
Posted to uk.d-i-y
Andy Hall
 
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Default Combi boiler - condensing - or not?

On Fri, 17 Mar 2006 17:03:26 -0000, "Tim Downie"
wrote:

Andy Hall wrote:

For heating running for a third of the day, the implication would be
of 5.5kWh per day. However, it's unlikely that all of the heat could
be recovered - perhaps 30% - so we are talking about say 2kWh/day.


Why only 30%? Genuine question. If you run gases in opposite directions
you always have a thermal gradient between incoming and outgoing gas which
makes countercurrent heat exchangers potentially very effective.

This works out to about £15/year.


Unless more than 30% is attainable.


OK, so even if it's 50 or 60%, it's still marginal.



Of course, this is estimation, but I think it's reasonable
approximation within half an order of magnitude

There are other places to obtain a better ROI.


Not if you can knock one up for £15. ;-) Bit of plastic drain pipe and a SS
exhaust cutoff from the local Quikfit.


Possibly, but unless you had a long length of it, you wouldn't get the
surface area needed to achieve the transfer. Think about heat
exchangers inside boilers and also plate heat exchangers for heating
water. These have huge surface areas by comparison.


--

..andy

  #44   Report Post  
Posted to uk.d-i-y
Tony Bryer
 
Posts: n/a
Default Combi boiler - condensing - or not?

On Fri, 17 Mar 2006 19:22:02 +0000 Andy Hall wrote :
Possibly, but unless you had a long length of it, you wouldn't get
the surface area needed to achieve the transfer. Think about heat
exchangers inside boilers and also plate heat exchangers for heating
water. These have huge surface areas by comparison.


I assume that what is envisaged is an insulated doughnut containing
combi pre-heat water with a length of ss flue passing though the middle
so that the heat from the flue pre-heats the water. A key problem ISTM
is that when the boiler stops you have this doughnut of warm water but
if you don't make use of it pretty quickly it will lose heat back into
the flue to the outside cold air. Likewise on one of those spring or
autumn days that is nice and mild but cold at night this heat exchanger
will turn into a pre-cooler.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm
[Latest version QSEDBUK 1.12 released 8 Dec 2005]


  #45   Report Post  
Posted to uk.d-i-y
Ed Sirett
 
Posts: n/a
Default Combi boiler - condensing - or not?

On Thu, 16 Mar 2006 14:03:59 -0800, CharlieR wrote:

Hi - I'm new to this forum but would appreciate some helpful advice.
I live in a flat and am having the kitchen refitted, which means moving
or replacing our existing boiler (Alpha Ocean Style FF - about 12 yrs
old).
I'm told that if we replace it we have to have a condensing boiler (new
building regs), but I understand that there are problems with the plume
from this type of boiler as we have a balcony roof above where the flue
would exit, and it's close to a door and a window.
The cheaper option is to just move the Alpha, but I'm worried this may
affect it (cause leaks). Or can we get a new non-condensing boiler
fitted?
I've spoken to 4 different heating companies (incl BG) and have had
different comments and advice from each.
Any help much appreciated. Thanks.


Look over the BoilerCHoice FAQ it may help.



--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html




  #46   Report Post  
Posted to uk.d-i-y
John Rumm
 
Posts: n/a
Default Combi boiler - condensing - or not?

Doctor Drivel wrote:

Chav, you really are a dumbo. Here is the GasTec report:
http://www.zenexenergy.com/downloads/Final%20GasTec%20report%20for%20Zenex.pdf


Chump, gullible could have been a word made for you...

Look at the hot water draw off pattern they used for testing. Lots of
unrealistically small 1.8l bursts that could be satisfied from the
stored water. For many instalations you will use 1.8l just running off
the dead leg. 24l for a shower - great if you only want 2 mins in there
- but remember some folks might actually want to get clean. What about
baths - even your mythical 100L bath will make a big dent in those
figures. They also seem to be assuming that a 30kW combi will be running
at that power output into the CH for three hours a day in order to have
enough captured waste heat in the first place.

Not exactly a realistic scenario is it. Still realism was never your
strong point was it.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/
  #47   Report Post  
Posted to uk.d-i-y
Andy Hall
 
Posts: n/a
Default Combi boiler - condensing - or not?

On Fri, 17 Mar 2006 20:57:58 +0000, John Rumm
wrote:

Doctor Drivel wrote:

Chav, you really are a dumbo. Here is the GasTec report:
http://www.zenexenergy.com/downloads/Final%20GasTec%20report%20for%20Zenex.pdf


Chump, gullible could have been a word made for you...

Look at the hot water draw off pattern they used for testing. Lots of
unrealistically small 1.8l bursts that could be satisfied from the
stored water. For many instalations you will use 1.8l just running off
the dead leg. 24l for a shower - great if you only want 2 mins in there
- but remember some folks might actually want to get clean. What about
baths - even your mythical 100L bath will make a big dent in those
figures. They also seem to be assuming that a 30kW combi will be running
at that power output into the CH for three hours a day in order to have
enough captured waste heat in the first place.

Not exactly a realistic scenario is it. Still realism was never your
strong point was it.


It's amazing what a manufacturer can achieve by paying for a test
report.

--

..andy

  #48   Report Post  
Posted to uk.d-i-y
Doctor Drivel
 
Posts: n/a
Default Combi boiler - condensing - or not?


"John Rumm" wrote in message
...
Doctor Drivel wrote:

Chav, you really are a dumbo. Here is the GasTec report:
http://www.zenexenergy.com/downloads/Final%20GasTec%20report%20for%20Zenex.pdf


Chump, gullible


Chav, take it with a respected Gas test house in Holland if your Chavness
thinks otherwise.

  #49   Report Post  
Posted to uk.d-i-y
Doctor Drivel
 
Posts: n/a
Default Combi boiler - condensing - or not?


"John Rumm" wrote in message
...

Not exactly a realistic scenario is it. Still realism was never your
strong point was it.


Chav, you must read again. You are clearly not a very bright person.

  #50   Report Post  
Posted to uk.d-i-y
Doctor Drivel
 
Posts: n/a
Default Combi boiler - condensing - or not?


"Andy Hall" aka Matt wrote in message
...
On Fri, 17 Mar 2006 20:57:58 +0000, John Rumm
wrote:

Doctor Drivel wrote:

Chav, you really are a dumbo. Here is the GasTec report:
http://www.zenexenergy.com/downloads/Final%20GasTec%20report%20for%20Zenex.pdf


Chump, gullible could have been a word made for you...

Look at the hot water draw off pattern they used for testing. Lots of
unrealistically small 1.8l bursts that could be satisfied from the
stored water. For many instalations you will use 1.8l just running off
the dead leg. 24l for a shower - great if you only want 2 mins in there
- but remember some folks might actually want to get clean. What about
baths - even your mythical 100L bath will make a big dent in those
figures. They also seem to be assuming that a 30kW combi will be running
at that power output into the CH for three hours a day in order to have
enough captured waste heat in the first place.

Not exactly a realistic scenario is it. Still realism was never your
strong point was it.


It's amazing what a manufacturer can achieve by paying for a test
report.


Matt, yep, an objective report. Amazing isn't it.



  #51   Report Post  
Posted to uk.d-i-y
John Rumm
 
Posts: n/a
Default Combi boiler - condensing - or not?

Andy Hall wrote:

Not exactly a realistic scenario is it. Still realism was never your
strong point was it.



It's amazing what a manufacturer can achieve by paying for a test
report.


Yup, just define the criteria so that it is narrow enough, cough up the
cash and you can get away with murder.... after all it worked on Hutton!


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/
  #52   Report Post  
Posted to uk.d-i-y
Andy Hall
 
Posts: n/a
Default Combi boiler - condensing - or not?

On Fri, 17 Mar 2006 22:16:47 -0000, "Doctor Drivel"
wrote:


"Andy Hall" aka Matt wrote in message
.. .
On Fri, 17 Mar 2006 20:57:58 +0000, John Rumm
wrote:

Doctor Drivel wrote:

Chav, you really are a dumbo. Here is the GasTec report:
http://www.zenexenergy.com/downloads/Final%20GasTec%20report%20for%20Zenex.pdf

Chump, gullible could have been a word made for you...

Look at the hot water draw off pattern they used for testing. Lots of
unrealistically small 1.8l bursts that could be satisfied from the
stored water. For many instalations you will use 1.8l just running off
the dead leg. 24l for a shower - great if you only want 2 mins in there
- but remember some folks might actually want to get clean. What about
baths - even your mythical 100L bath will make a big dent in those
figures. They also seem to be assuming that a 30kW combi will be running
at that power output into the CH for three hours a day in order to have
enough captured waste heat in the first place.

Not exactly a realistic scenario is it. Still realism was never your
strong point was it.


It's amazing what a manufacturer can achieve by paying for a test
report.


Matt, yep, an objective report. Amazing isn't it.


Remind me to email you some other product reports and the number of
one of my offshore accounts so that you can make the payment for your
purchases.

Do you buy Lottery tickets at all?



--

..andy

  #53   Report Post  
Posted to uk.d-i-y
Andy Hall
 
Posts: n/a
Default Combi boiler - condensing - or not?

On Fri, 17 Mar 2006 22:30:37 +0000, John Rumm
wrote:

Andy Hall wrote:

Not exactly a realistic scenario is it. Still realism was never your
strong point was it.



It's amazing what a manufacturer can achieve by paying for a test
report.


Yup, just define the criteria so that it is narrow enough, cough up the
cash and you can get away with murder.... after all it worked on Hutton!



It certainly did. Literally.....



--

..andy

  #54   Report Post  
Posted to uk.d-i-y
Andy Hall
 
Posts: n/a
Default Combi boiler - condensing - or not?

On Fri, 17 Mar 2006 22:14:14 -0000, "Doctor Drivel"
wrote:


"John Rumm" wrote in message
...
Doctor Drivel wrote:

Chav, you really are a dumbo. Here is the GasTec report:
http://www.zenexenergy.com/downloads/Final%20GasTec%20report%20for%20Zenex.pdf


Chump, gullible


Chav, take it with a respected Gas test house in Holland if your Chavness
thinks otherwise.


Don't be silly.

You can give a commission to any test house or consulting firm and
define the criteria in such a way as to produce the outcome that you
want to have for marketing purposes.

They do need to tell any lies, but the results will not be objective
either.

I suppose that you believe advertorials in magazines as well....




--

..andy

  #55   Report Post  
Posted to uk.d-i-y
Doctor Drivel
 
Posts: n/a
Default Combi boiler - condensing - or not?


"Andy Hall" aka Matt wrote in message
...
On Fri, 17 Mar 2006 22:14:14 -0000, "Doctor Drivel"
wrote:


"John Rumm" wrote in message
...
Doctor Drivel wrote:

Chav, you really are a dumbo. Here is the GasTec report:
http://www.zenexenergy.com/downloads/Final%20GasTec%20report%20for%20Zenex.pdf

Chump, gullible


Chav, take it with a respected Gas test house in Holland if your Chavness
thinks otherwise.


Don't be silly.

You can give a commission to any test house or consulting firm and
define the criteria in such a way as to produce the outcome that you
want to have for marketing purposes.

They do need to tell any lies, but the results will not be objective
either.


Matt, have you any evidence of this firm skulduggery?



  #56   Report Post  
Posted to uk.d-i-y
Andy Hall
 
Posts: n/a
Default Combi boiler - condensing - or not?

On Sat, 18 Mar 2006 00:02:16 -0000, "Doctor Drivel"
wrote:


"Andy Hall" aka Matt wrote in message
.. .
On Fri, 17 Mar 2006 22:14:14 -0000, "Doctor Drivel"
wrote:


"John Rumm" wrote in message
...
Doctor Drivel wrote:

Chav, you really are a dumbo. Here is the GasTec report:
http://www.zenexenergy.com/downloads/Final%20GasTec%20report%20for%20Zenex.pdf

Chump, gullible

Chav, take it with a respected Gas test house in Holland if your Chavness
thinks otherwise.


Don't be silly.

You can give a commission to any test house or consulting firm and
define the criteria in such a way as to produce the outcome that you
want to have for marketing purposes.

They do need to tell any lies, but the results will not be objective
either.


Matt, have you any evidence of this firm skulduggery?


OK. One more time.

Take a read through the report. Properly.

"Testwork"

"Zenex retained GaC to determine the energy savings possible from the
Energy GasSaver."

This means that Zenex paid Gastec to do test work and produce a
report. It was not that Gastec did this independently and out of the
goodness of their hearts.

The basic pattern of use of the heating that was assumed is not
reasonable, and neither is the volume of hot water use.

Much of the rest of the report is based on theoretical assumptions
which the author points out should be verified experimentally.

Nobody is suggesting any impropriety in what was actually done.
However, the measurements and assumptions are a long way from
practical use and the further experiments recommended were not done as
part of this work.

In other words, it's the minimum amount to suggest some promise in the
product (but not under realistic conditions of use). The
comprehensive work to actually establish useful data experimentally
was either not carried out or not included in the report.

It doesn't have a lot of real value.


--

..andy

  #57   Report Post  
Posted to uk.d-i-y
Doctor Drivel
 
Posts: n/a
Default Combi boiler - condensing - or not?


"Andy Hall" akak Matt wrote in message
...
On Sat, 18 Mar 2006 00:02:16 -0000, "Doctor Drivel"
wrote:


"Andy Hall" aka Matt wrote in message
. ..
On Fri, 17 Mar 2006 22:14:14 -0000, "Doctor Drivel"
wrote:


"John Rumm" wrote in message
...
Doctor Drivel wrote:

Chav, you really are a dumbo. Here is the GasTec report:
http://www.zenexenergy.com/downloads/Final%20GasTec%20report%20for%20Zenex.pdf

Chump, gullible

Chav, take it with a respected Gas test house in Holland if your
Chavness
thinks otherwise.

Don't be silly.

You can give a commission to any test house or consulting firm and
define the criteria in such a way as to produce the outcome that you
want to have for marketing purposes.

They do need to tell any lies, but the results will not be objective
either.


Matt, have you any evidence of this firm skulduggery?


OK. One more time.


Matt, so you haven't then.

  #58   Report Post  
Posted to uk.d-i-y
Doctor Drivel
 
Posts: n/a
Default Combi boiler - condensing - or not?


"Andy Hall" wrote in message
news
On Sat, 18 Mar 2006 11:04:12 -0000, "Doctor Drivel"
wrote:


"Andy Hall" akak Matt wrote in message
. ..
On Sat, 18 Mar 2006 00:02:16 -0000, "Doctor Drivel"
wrote:


"Andy Hall" aka Matt wrote in message
m...
On Fri, 17 Mar 2006 22:14:14 -0000, "Doctor Drivel"
wrote:


"John Rumm" wrote in message
...
Doctor Drivel wrote:

Chav, you really are a dumbo. Here is the GasTec report:
http://www.zenexenergy.com/downloads/Final%20GasTec%20report%20for%20Zenex.pdf

Chump, gullible

Chav, take it with a respected Gas test house in Holland if your
Chavness
thinks otherwise.

Don't be silly.

You can give a commission to any test house or consulting firm and
define the criteria in such a way as to produce the outcome that you
want to have for marketing purposes.

They do need to tell any lies, but the results will not be objective
either.

Matt, have you any evidence of this firm skulduggery?

OK. One more time.


Matt, so you haven't then.



Just read the report. If you can't figure out the fallacies

Matt, you are not a position to recognise fallacies.

  #59   Report Post  
Posted to uk.d-i-y
Gav
 
Posts: n/a
Default Combi boiler - condensing - or not?

CharlieR wrote:
Hi - I'm new to this forum but would appreciate some helpful advice.
I live in a flat and am having the kitchen refitted, which means moving
or replacing our existing boiler (Alpha Ocean Style FF - about 12 yrs
old).
I'm told that if we replace it we have to have a condensing boiler (new
building regs), but I understand that there are problems with the plume
from this type of boiler as we have a balcony roof above where the flue
would exit, and it's close to a door and a window.
The cheaper option is to just move the Alpha, but I'm worried this may
affect it (cause leaks). Or can we get a new non-condensing boiler
fitted?
I've spoken to 4 different heating companies (incl BG) and have had
different comments and advice from each.
Any help much appreciated. Thanks.

as a budding(30 year old) gas/heating engineeer and plumber, i would
bite the bullit and go for the condenser, do you live on top floor? if
so have you got sole access to loft? if so stck it up there out of the way!

if not, and plume will cause problems, as said before look through the
regs and find a good way of avoiding 'em or move it yourself!
  #60   Report Post  
Posted to uk.d-i-y
Gav
 
Posts: n/a
Default Combi boiler - condensing - or not?

Gav wrote:
CharlieR wrote:
Hi - I'm new to this forum but would appreciate some helpful advice.
I live in a flat and am having the kitchen refitted, which means moving
or replacing our existing boiler (Alpha Ocean Style FF - about 12 yrs
old).
I'm told that if we replace it we have to have a condensing boiler (new
building regs), but I understand that there are problems with the plume
from this type of boiler as we have a balcony roof above where the flue
would exit, and it's close to a door and a window.
The cheaper option is to just move the Alpha, but I'm worried this may
affect it (cause leaks). Or can we get a new non-condensing boiler
fitted?
I've spoken to 4 different heating companies (incl BG) and have had
different comments and advice from each.
Any help much appreciated. Thanks.

as a budding(30 year old) gas/heating engineeer and plumber, i would
bite the bullit and go for the condenser, do you live on top floor? if
so have you got sole access to loft? if so stck it up there out of the way!

if not, and plume will cause problems, as said before look through the
regs and find a good way of avoiding 'em or move it yourself!

if you email me i will forward the info i have on deciding where to site
the flue
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