"Tony Bryer" wrote in message
...
In article , Matt
Beard wrote:

If this isn't a CPSU then what is? It even has
an optional immersion
heater in the cylinder!

Using the definitions in SAP, a storage combi is much like a
boiler/pump/cylinder system in one box. In a CPSU the burner heats a
thermal store which has a heat exchanger coil running through and DHW
is heated as it runs through this coil. IOW in a storage combi, the
water in the store comes out of the taps; in a CPSU it doesn't.

A CPSU has BOTH the DHW and CH taken from the thermal store, or heat bank.
The Worcester-Bosch HighFlow, and Vokera, have heat banks and are classed
as combi's because only the DHW runs through the heat bank.

On 22 Jun 2004 05:42:56 -0700, (timegoesby)
wrote:



I have been assessing this Alpha combi and the new Powermax, as I like
packaged heating and hot water. I find these idiot proof as I don't
have to think out the system or control wiring. The Alpha is indeed a
two stage flow combi, so you never run out of hot water. I confirmed
this with Alpha. The Powermaxes have large storage unvented vessels
which make it unlikly to run out of hot water. The reheating times on
both are very good, which leads me to believe they will be reheating
water fast as you use it. This very fast reheating must extend the
cylinder size as such.

Be careful on that. It can only, by definition heat the water as
rapidly as the energy going in - in this case 25kW - not very
exciting. If the cylinder runs out of hot water, it is going to give
a fairly poor performance equivalent to a low to mid range combi.

There is no functional difference between the Potterton product and a
standard boiler plus fast recover cylinder.

The only reason it can claim to have "continuous" hot water is on the
basis that the cylinder doesn't run out. It certainly is not
heating the water as fast as it is being used. 30-48lpm needs more
than 25kW to provide it. The manufacturer does not state the
temperature rise in these figures either which suggests some
"marketing" of the figures.



Sedbuk does class both as a combi. I am leaning towards the Alpha.

Sedbuk has it wrong. Potterton does not claim that for their
product..


..andy

To email, substitute .nospam with .gl

On Tue, 22 Jun 2004 22:21:51 +0100, "IMM" wrote:


"Andy Hall" wrote in message
news
On Tue, 22 Jun 2004 00:23:33 +0100, "IMM" wrote:



The IMI Powermax, the old version.
The new "Potterton" Powermax is a combi,
and classed as one. Look up Powermax in sedbuk.

It may be by Sedbuk, but there are numerous
other mistakes in their database

If you look at the Potterton web site or
more specifically download
the brochure, they don't use the word
combi or anything like it in the
description, going for descriptions like
"packaged system in a box"

Which is a combi.

A combi is generally accepted to be an instantaneous water heater and
heating boiler.


SEDBUK make the classification, not the makers.

In this case they didn't look closely.

Potterton's marketing
people are attempting to put the Powermax in a category of its own. Those
who know these things can see through this. You can't.

Of course Potterton are trying to differentiate their product. This
is because it is nothing more than a packaging exercise. There is
nothing clever about it. Functionally, it is much more like a
system boiler with added cylinder in the case than anything to do with
a combi.


If you look at the cut away view of
the thing it's basically a
conventional boiler and water cylinder
in one box with a high
recovery coil.

Hardly rocket science.

But they put it in one box and matched the cylinder/boiler/controls to
maximise efficiency.

It doesn't need to be done this way to achieve that. It is a
packaging exercise. There is nothing in it, as its spec shows, that
makes it more efficient than any other condensing boilers. Also,
there is quite a bit of specmanship in the claims bing made regarding
performance.

There's nothing wrong with a clever packaging exercise, but this is
not a revolutionary new invention.


..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On 22 Jun 2004 05:42:56 -0700, (timegoesby)
wrote:



I have been assessing this Alpha combi and the new Powermax, as I like
packaged heating and hot water. I find these idiot proof as I don't
have to think out the system or control wiring. The Alpha is indeed a
two stage flow combi, so you never run out of hot water. I confirmed
this with Alpha. The Powermaxes have large storage unvented vessels
which make it unlikly to run out of hot water. The reheating times on
both are very good, which leads me to believe they will be reheating
water fast as you use it. This very fast reheating must extend the
cylinder size as such.

Be careful on that. It can only, by definition heat the water as
rapidly as the energy going in - in this case 25kW - not very
exciting. If the cylinder runs out of hot water, it is going to give
a fairly poor performance equivalent to a low to mid range combi.

But it still does not run out of hot water, a fact you can't seen to
comprehend, which any conventional cylinder/boiler setup will run out. The
Alpha is approx 19 litres/min of water at 65C, and when the cylinder is
exhausted the flow reduces and approx 11 l/min is delivered FOR EVER. So a
very large bath can be filled reasonably quickly. The recovery rate of the
cylinder is zippo too.

There is no functional difference
between the Potterton product and a
standard boiler plus fast recover cylinder.

Nonsense!!! Potterton engineers (who are far more expert than some smart
arse DIYers) have matched the boiler/cylinder size/coil/recovery rate, etc,
to maximize efficiency. They have also simplified the electrical side of it
too. All in one box and a doddle to fit.

The only reason it can claim to
have "continuous" hot water is on the
basis that the cylinder doesn't run out.
It certainly is not heating the water as
fast as it is being used.

That depends on how much is being used. Someone having a normal flowrate
shower may not be emptying the cylinder faster than the boiler is
re-heating, so infinitely continuous hot water.

Sedbuk does class both as a combi.
I am leaning towards the Alpha.

Sedbuk has it wrong.

Sedbuk has it right!!! See my explanation of what a combi and CPSU is.

Potterton does not claim that for their
product..

Their marketing department can what they like. The BRE is there is tell us
the real story, not maker marketing, which you suck in and blow out.

An explanation for you....

Firstly, a combi is a "combination" of the heating and water system in one
case, eliminating external tanks and cylinders, and generally supply hot
water at high main pressure. To confuse a little, some can run at very low
pressures and even off tanks. Generally most are fed from the mains. It is
generally a matter of mounting the boiler and connect up the pipes. The
expert designers have done the hard work for you and put all in one case.

There are three types of combi:

1) The Infinitely Continuous Combi -

Heats cold mains water instantly as it runs through the combi. It never runs
out of hot water. This is the most common type of combi, generally having
lower flowrates than Nos 2 & 3 below. The largest flow rate instant combi is
a two bathroom model, 22 litres/min ECO-Hometec. Being a condenser it is
very economical too. http://www.eco-hometec.co.uk

2) Unvented Cylinder Combi -

An unvented cylinder is a similar to a conventional cylinder but run off the
high-pressure cold mains. A combi with an integral unvented cylinder has
approx 60 litre cylinder heated to approx 80C, with a quick recovery coil
that takes all the boilers output. A fast acting cylinder thermostat ensures
the boiler pumps heat into the cylinder ASAP with a recovery rate from cold
around 5-8 mins (Ariston claim 8 mins). The 80C water is blended down to
about 45-50C. e.g's, Ariston Genus 27 Plus, Glow Worm, Powermax, Alpha
CB50.

3) Invinately Continuous/Unvented cylinder combi -

The Alpha CB50 is a combination of both having atwo stage flowrate, of high
flowrate when using the stored water with an automatic flow regulator
switching in to reduce flow to an invinately continuous flowrate of approx
11 litres/min.
http://www.alpha-boilers.com/products/CB50.html

4) Heat Bank Combi -

Incoming water is instantly heated running through a plate heat exchanger
(as is most instantaneous combi's) that takes its heat from a "domestic hot
water only" store of water at approx 80C (instantaneous combi's take the
heat from a heat-exchanger heater via the burner). A fast acting thermostat
ensures the boiler pumps all of its heat into the store ASAP with a recovery
rate about 5-8 mins from cold. The 80C water is blended down to about
45-50C. They are generally two stage flow rates, in that when the thermal
store is exhausted it reverts to what the bunrer can produce, which isapprox
11-12 litre/minute. e.g. Vokera & Worcester floor standing models (standard
washing machine sizes).

N.B. The heat bank is a variation of a thermal store, but is "not" a thermal
store in the conventional sense in that a coil carrying cold mains water
runs though a store of hot water kept at about 80C. Heat-banks are far more
efficient and give higher flowrates than conventional coiled thermal stores.
The stainless steel plate heat-exchangers do not scale up so easily.

5) Combined Primary Storage Unit
(Not classed as a combi, but a derivative of a combi, but still a one box
solution, so still in the same family)

These are a combination of a large thermal store, or heat bank, and boiler
in one casing. The units are large (larger than standard washing machine
size) and floor mounted. The heating is taken off the thermal store, which
in many cases the DHW taken off the store using a plate heat-exchanger
(heat-bank). Unlike the Heat-bank in 3) above the thermal store supplies
heating "and" DHW, giving the "combined" to the title. They are available
from 1 to 2.5 bathroom models. Gledhill do an excellent condensing
version, the Gulfsream 2000. http://www.gledhill.net

Nos. 2) 3) 4) & 5) have high flowrates. No. 1 "generally" has low flowrates
but there are always exceptions and some can be high - e.g. the ECO-Hometec
infinitely continuous combi, actually has a very high flowrate.

Nos 2), 3) 4) & 5) use stored water, but in different ways. Unlike No. 1
"some" versions will eventually run cold, but that takes quite a time, hence
some are referred to as "two bathroom" models, having the ability to fill
two baths with very fast recovery rates. As hot water is being drawn off
the high rating burner is also reheating. Very rare do these combi's run
out of hot water in average use. When taking one shower the burner may be
re-heating faster than what can be drawn-off. No. 3) above uses stored
water but will not run out of hot water (high and low flowrates). Most
versions of N. 4) above are two stage flowrate models (high and low
flowrates) and will also not run out of hot water.

There are combi models that give hot water and heating simultaneously as
Combined Primary Storage Units do. Most don't as they are hot water
priority.

"IMM" wrote in message
...

"Lurch" wrote in message
...
On Tue, 22 Jun 2004 01:25:32 +0100, "IMM" strung
together this:

My Glow-worm Cxi came with a flying lead on which (at a minimum, non
Part L complying of course) you needed to put a 13A plug. I'm not
sure
whether this counts as 'wiring'

Yes it does, it was wired both at the factory and upon installation. A
combi does need wiring to work.

They don't understand.

Bold statement coming from one so clueless.

Bean, you haven't a clue.



IMM,

We ALL know what you meant to say, that combi boilers do not require as mush
wiring as other boilers, but that is not what you originally said and all
you are doing is digging yourself in deeper - do yourself a favour and just
admit that you got it wrong.

"Andy Hall" wrote in message
...
On Tue, 22 Jun 2004 22:21:51 +0100, "IMM" wrote:


"Andy Hall" wrote in message
news
On Tue, 22 Jun 2004 00:23:33 +0100, "IMM" wrote:



The IMI Powermax, the old version.
The new "Potterton" Powermax is a combi,
and classed as one. Look up Powermax in sedbuk.

It may be by Sedbuk, but there are numerous
other mistakes in their database

If you look at the Potterton web site or
more specifically download
the brochure, they don't use the word
combi or anything like it in the
description, going for descriptions like
"packaged system in a box"

Which is a combi.

A combi is generally accepted to be
an instantaneous water heater and
heating boiler.

You mean what YOU accept it to be. See my post explaining all the types of
combi.

SEDBUK make the classification, not the makers.

In this case they didn't look closely.

Loosing this one aren't you! As usual.

Potterton's marketing
people are attempting to put the Powermax in a category of its own.
Those
who know these things can see through this. You can't.

Of course Potterton are trying to differentiate their product. This
is because it is nothing more than a packaging exercise. There is
nothing clever about it. Functionally, it is much more like a
system boiler with added cylinder in the case than anything to do with
a combi.

The word combi is short for "combination". All the heating and hot water
are combined into one box. A one box solution. Now you know.

If you look at the cut away view of
the thing it's basically a
conventional boiler and water cylinder
in one box with a high
recovery coil.

Hardly rocket science.

But they put it in one box and matched
the cylinder/boiler/controls to
maximise efficiency.

It doesn't need to be done this
way to achieve that.

Unless you are a heating engineer, it is best leave it to the design
engineers. You are neither.

It is a packaging exercise.

Ah! he is learning. Yes they packackage the CH and DHW into one box.

There's nothing wrong with a clever packaging exercise, but this is
not a revolutionary new invention.

No one said it was.

On Tue, 22 Jun 2004 23:24:28 +0100, "IMM" wrote:


"Andy Hall" wrote in message
.. .
On Tue, 22 Jun 2004 22:21:51 +0100, "IMM" wrote:



A combi is generally accepted to be
an instantaneous water heater and
heating boiler.

You mean what YOU accept it to be.

It is also what the industry accepts it to be - a boiler for producing
instantaneous hot water and space heating as well.

You bang on about the apparent virtues of this versus storage systems
enough.




Of course Potterton are trying to differentiate their product. This
is because it is nothing more than a packaging exercise. There is
nothing clever about it. Functionally, it is much more like a
system boiler with added cylinder in the case than anything to do with
a combi.

The word combi is short for "combination". All the heating and hot water
are combined into one box. A one box solution. Now you know.

On that basis, one could argue that CPSUs and other combined systems
are combis.

The essence is still the same. In this case a relatively small 25kW
boiler is augmented with a cylinder.



If you look at the cut away view of
the thing it's basically a
conventional boiler and water cylinder
in one box with a high
recovery coil.

Hardly rocket science.

But they put it in one box and matched
the cylinder/boiler/controls to
maximise efficiency.

It doesn't need to be done this
way to achieve that.

Unless you are a heating engineer, it is best leave it to the design
engineers. You are neither.

Neither are you. However I can spot spec. extrapolation when I see
it, and this is being done here with respect to HW delivery. A lot
is left unsaid. There's no clever engineering in it.



..andy

To email, substitute .nospam with .gl

On Tue, 22 Jun 2004 23:15:58 +0100, "IMM" wrote:



But it still does not run out of hot water, a fact you can't seen to
comprehend, which any conventional cylinder/boiler setup will run out.

Not true. The heat is being replaced in the cylinder by the boiler.
The effectiveness of that will depend on the power level of the boiler
and efficiency of the heat exchanger. Once the HW is used up, the
temperature of the produced HW will fall or can be maintained at a
higher temperature if the flow is reduced.

The
Alpha is approx 19 litres/min of water at 65C, and when the cylinder is
exhausted the flow reduces and approx 11 l/min is delivered FOR EVER.

Well obviously. There's no difference between this and what I
described above. If the flow rate is reduced, the temperature rise
from cold mains can be maintained.

A much better solution is to have the cylinder adequately sized in the
first place so that all the water likely to be required in the
practical situation can be drawn at the higher flow rate and the
condition of rate reduction does not arise.

So a
very large bath can be filled reasonably quickly. The recovery rate of the
cylinder is zippo too.

There is no functional difference
between the Potterton product and a
standard boiler plus fast recover cylinder.

Nonsense!!! Potterton engineers (who are far more expert than some smart
arse DIYers) have matched the boiler/cylinder size/coil/recovery rate, etc,
to maximize efficiency. They have also simplified the electrical side of it
too. All in one box and a doddle to fit.

Lovely. If you believe the brochures. There is a lot of missing
information related to the performance and even Potterton engineers
are not able to defy thermodynamics.



The only reason it can claim to
have "continuous" hot water is on the
basis that the cylinder doesn't run out.
It certainly is not heating the water as
fast as it is being used.

That depends on how much is being used. Someone having a normal flowrate
shower may not be emptying the cylinder faster than the boiler is
re-heating, so infinitely continuous hot water.

At 25kW heat input, the water is going to be being used in a decent
shower faster than it is being produced.



..andy

To email, substitute .nospam with .gl

"IMM" wrote in message
...

"Matt Beard" wrote in message
...
In article ,
says...

* They require a minimum of a 40A circuit.
* They have small inlet and outlet size
(3/8" seems typical)

There are models aroud with 15mm connections.

Is it OK to restrict the output
of the combi to a 15mm pipe then, I
would have thought that this would limit
the flow rate.

Most combi's have a 15mm connection.

* They all recommend "spray taps" and
most say they are not suitable
for baths, however it seems that they
can supply a shower.

Spray, or aerated, tap are advisable for all installations as they use
less
water. They are the normal in most of Europe, except in backward
Britain.

Sounds interesting... I guess they don't use
them on the bath though.

They do.

When you say to install in the draw-off,
I assume you are meanng that
I should install it so that all of the hot
water that is normally heated by the combi
flows through the electric heater (turned off
normally!).

Yes.

I'm still concerned about restricting the flow though.

I can see that this would produce
the desired result, but
am concerned that the small bore of
the inlet and outlet pipes of the
electric heater would restrict the flow.

You may only want to fix it on a section
of the draw-off that does not
require a large flow: kitchen and basin
for e,g. Larger bores are available.

Hmm, This would need some careful planning.
Perhaps split the output of the combi into
1 x 22mm and 1 x 15mm.

15mm on both legs.

Take the 15mm
through the electric
backup heater and on to the kitchen
and all sink taps. The 22mm can co
to the bath taps (giving good flow, but
not working in backup mode -
which is OK because the electric heater
will not do a bath anyway).
What about the shower, should this be
in the high-flow-no-backup or the
low-flow-with-backup? I would prefer a high
flow shower, but I don't
like the idea of being without either bath or
shower if anything were to
go wrong with the boiler.

Have the shower and sink go through the electric heater, then hot water at
kitchen and shower.

this the best way to go,
or should I fit it in some other way.

You could fit it in parallel and have a
manual 3-way valve that diverts
the flow to the taps or through the
instant heater.

Sounds maybe even better, but wouldn't
this be a complicated little set
of pipework?

No. The combi draw-off to the 3 way valve . One outlet of the valve to
the
electric heater, the other to the taps. The outlet of the electric
heater,
tees into the draw-off.

I tried to sketch it out, but it starts looking like an
oil refinery!!

You could have one cheap 1/4 turn full bores valve. From combi's DHW
draw-off insert a full bore valve. Fit a tee before and after the valve and
have the electric heater between the tees. When the valve is open, most
flow runs around the electric heater. When close all runs though the
heater. Simple and effective.

"Andy Hall" wrote in message
...
On Tue, 22 Jun 2004 23:15:58 +0100, "IMM" wrote:

But it still does not run out of hot water,
a fact you can't seem to comprehend, which
any conventional cylinder/boiler setup will run out.

Not true.

This one is dumb! Read my explaination.

The Alpha is approx 19 litres/min of
water at 65C, and when the cylinder is
exhausted the flow reduces and approx
11 l/min is delivered FOR EVER.

Well obviously.

Gosh! he is learning.

There's no difference between this and what I
described above. If the flow rate is reduced,
the temperature rise from cold mains can be
maintained.

The Alpha has an internal coil specifically designed to operate efficiently
at the low flowrate stage. You willNEVER run out of hot water. The W-B
HighFlow and Vokera using heat banks will not run out of hot water, but you
have to manually reduce the tap to lower the flowrate. The CB50 does it
automatically.

A much better solution is to have
the cylinder adequately sized in the
first place

As stored water combi's have.

snip drivel

Nonsense!!! Potterton engineers (who are far more expert than some smart
arse DIYers) have matched the boiler/cylinder size/coil/recovery rate,
etc,
to maximize efficiency. They have also simplified the electrical side of
it
too. All in one box and a doddle to fit.

Lovely. If you believe the brochures.

I believe in performance they deliver. You are the one quoting, and
believing brochures, not me.

The only reason it can claim to
have "continuous" hot water is on the
basis that the cylinder doesn't run out.
It certainly is not heating the water as
fast as it is being used.

That depends on how much is being used. Someone having a normal flowrate
shower may not be emptying the cylinder faster than the boiler is
re-heating, so infinitely continuous hot water.

At 25kW heat input, the water is going to be being used in a decent
shower faster than it is being produced.

28kW on the Alpha, and delivering around 11 litres/min, which the whole of
Europe, whoc have bought combi's of that flowrate by the millions, deem
suitable for one shower.

Now you know. Er, no. he doesn't. It will not sink in.

On Wed, 23 Jun 2004 00:11:18 +0100, "IMM" wrote:



The Alpha has an internal coil specifically designed to operate efficiently
at the low flowrate stage. You willNEVER run out of hot water. The W-B
HighFlow and Vokera using heat banks will not run out of hot water, but you
have to manually reduce the tap to lower the flowrate. The CB50 does it
automatically.

The whole thing can be avoided by having an adequately sized cylinder
in the first place.



Nonsense!!! Potterton engineers (who are far more expert than some smart
arse DIYers) have matched the boiler/cylinder size/coil/recovery rate,
etc,
to maximize efficiency. They have also simplified the electrical side of
it
too. All in one box and a doddle to fit.

Lovely. If you believe the brochures.

I believe in performance they deliver. You are the one quoting, and
believing brochures, not me.

I pointed out the areas where the brochures conveniently avoid
mentioning awkward data like the real flow rate for winter temperature
mains water after the little cylinder empties..




28kW on the Alpha, and delivering around 11 litres/min, which the whole of
Europe, whoc have bought combi's of that flowrate by the millions, deem
suitable for one shower.


Because that's what's available on the market. Twice that rate is
needed for a worthwhile shower.


..andy

To email, substitute .nospam with .gl

In article ,
IMM wrote:
But it still does not run out of hot water, a fact you can't seen to
comprehend, which any conventional cylinder/boiler setup will run out.

Rubbish. A fast recovery cylinder will allow continuous 'hot' water -
given that you refuse to define what you mean by hot, or the flow.

--
*There's two theories to arguing with a woman. Neither one works *

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

"Andy Hall" wrote in message
...
28kW on the Alpha, and delivering around 11 litres/min, which the whole
of
Europe, whoc have bought combi's of that flowrate by the millions, deem
suitable for one shower.


Because that's what's available on the market. Twice that rate is
needed for a worthwhile shower.

54kW or 22 litres/min? You must the size fo house to need so much.

In article ,
IMM wrote:
The word combi is short for "combination". All the heating and hot water
are combined into one box. A one box solution. Now you know.

But wouldn't the case stop the heat from the rads getting into the room
efficiently?

--
*Even a blind pig stumbles across an acorn now and again *

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

IMM wrote:

28kW on the Alpha, and delivering around 11 litres/min, which the whole of
Europe, whoc have bought combi's of that flowrate by the millions, deem
suitable for one shower.

In the winter, that is going to be a feeble 6.6L/min of water if you
want it at the original 65 deg C...

(I do wish boiler manufactureres would use a more relistic temperature
delta for their hot water output than 35 degrees)


--
Cheers,

John.

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

Dave Plowman (News) wrote:

Rubbish. A fast recovery cylinder will allow continuous 'hot' water -
given that you refuse to define what you mean by hot, or the flow.

You should know that IMM will adjust definitions so as to best suit the
argument he is currently loosing... perhaps he should run for public office?

(Would fit right in with Mandelson, Byers, Darling, Jowell et al.
Comparable level of competence as well).

--
Cheers,

John.

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

On Wed, 23 Jun 2004 01:14:12 +0100, "nomatter" wrote:


"Andy Hall" wrote in message
.. .
28kW on the Alpha, and delivering around 11 litres/min, which the whole
of
Europe, whoc have bought combi's of that flowrate by the millions, deem
suitable for one shower.


Because that's what's available on the market. Twice that rate is
needed for a worthwhile shower.

54kW or 22 litres/min? You must the size fo house to need so much.


Two showers? Shower and a bath? Decent flow rate on one shower?

11 lpm doesn't do it.....


..andy

To email, substitute .nospam with .gl

"John Rumm" wrote in message
...
Dave Plowman (News) wrote:

Rubbish. A fast recovery cylinder will allow continuous 'hot' water -
given that you refuse to define what you mean by hot, or the flow.

You should know that IMM

snip tripe

"Andy Hall" wrote in message
...
On Wed, 23 Jun 2004 00:11:18 +0100, "IMM" wrote:



The Alpha has an internal coil specifically
designed to operate efficiently
at the low flowrate stage. You will NEVER
run out of hot water. The W-B
HighFlow and Vokera using heat banks
will not run out of hot water, but you
have to manually reduce the tap to lower
the flowrate. The CB50 does it
automatically.

The whole thing can be avoided

What can be avoided? Auto 2 stage flowrates?

by having an adequately sized cylinder
in the first place.

??? Do you mean we should all have large cylinders taking up needed space
that also look like a school boiler house

I believe in the performance they deliver.
You are the one quoting, and
believing brochures, not me.

I pointed out the areas where the
brochures conveniently avoid
mentioning

I said "I believe in the performance they deliver" and they deliver.

28kW on the Alpha, and delivering around
11 litres/min, which the whole of
Europe, who have bought combi's of that
flowrate by the millions, deem
suitable for one shower.

Because that's what's available on the market.

Nonsense!! High mad low flowrate combi's are on the market and now auto
duel flowrates too. They have the choice and those with the low flowrates
deem then more than suitable for showers.

Twice that rate is
needed for a worthwhile shower.

You are prattling balls. Or are you a devil cult member wanting to rid the
world of its natural, resources?

"Andy Hall" wrote in message
...
On Wed, 23 Jun 2004 01:14:12 +0100, "nomatter" wrote:


"Andy Hall" wrote in message
.. .
28kW on the Alpha, and delivering around 11 litres/min, which the
whole
of
Europe, whoc have bought combi's of that flowrate by the millions,
deem
suitable for one shower.


Because that's what's available on the market. Twice that rate is
needed for a worthwhile shower.

54kW or 22 litres/min? You must the size fo house to need so much.


Two showers? Shower and a bath? Decent flow rate on one shower?

11 lpm doesn't do it.....

The man is telling you to size to suit.

"John Rumm" wrote in message
...
IMM wrote:

28kW on the Alpha, and delivering around 11 litres/min, which the whole
of
Europe, whoc have bought combi's of that flowrate by the millions, deem
suitable for one shower.

In the winter, that is going to be a feeble 6.6L/min of water if you
want it at the original 65 deg C...

Where do they come from? A shower is approx 43C.

On Wed, 23 Jun 2004 13:56:27 +0100, "IMM" wrote:



The whole thing can be avoided

What can be avoided? Auto 2 stage flowrates?

Yes. It's a completely unneccessary compromise


by having an adequately sized cylinder
in the first place.

??? Do you mean we should all have large cylinders taking up needed space
that also look like a school boiler house

No, because the space is not significant and it doesn't look like a
school boiler house. You're suggesting putting a large box weighing
over 130kg on the kitchen wall that even then doesn't do the job
properly. Kitchen wall space in most homes is at far more premium
than the airing cupboard.



I believe in the performance they deliver.
You are the one quoting, and
believing brochures, not me.

I pointed out the areas where the
brochures conveniently avoid
mentioning

I said "I believe in the performance they deliver" and they deliver.


I believe in a few things as well, but not generally not from glossy
brochures.

28kW on the Alpha, and delivering around
11 litres/min, which the whole of
Europe, who have bought combi's of that
flowrate by the millions, deem
suitable for one shower.

Because that's what's available on the market.

Nonsense!! High mad low flowrate combi's are on the market and now auto
duel flowrates too. They have the choice and those with the low flowrates
deem then more than suitable for showers.

???


Twice that rate is
needed for a worthwhile shower.

You are prattling balls. Or are you a devil cult member wanting to rid the
world of its natural, resources?

What on earth are you talking about?


..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Wed, 23 Jun 2004 13:56:27 +0100, "IMM" wrote:



The whole thing can be avoided

What can be avoided? Auto 2 stage flowrates?

Yes. It's a completely unneccessary compromise

Prattling balls as usual. One of these NEVER runs out of hot water.

by having an adequately sized cylinder
in the first place.

??? Do you mean we should all have large cylinders taking up needed
space
that also look like a school boiler house

No, because the space is not
significant

In most smallish Britush homes it is.

and it doesn't look like a
school boiler house.

It does.

You're suggesting putting a large box

Not large.

weighing over 130kg

Weight doesn't matter as you don't lift it to have hot water.

on the kitchen wall that even
then doesn't do the job
properly.

It more than does the job and NEVER runs out of hot water.

Kitchen wall space in most homes is at far more premium
than the airing cupboard.

So you say. It can go under the stairs, in the loft, etc.

I believe in the performance they deliver.
You are the one quoting, and
believing brochures, not me.

I pointed out the areas where the
brochures conveniently avoid
mentioning

I said "I believe in the performance
they deliver" and they deliver.

I believe in a few things as well, but
not generally not from glossy
brochures.

Read back on the thread. You believe the Potterrton glossy on what is a
combi rather than the Builing Research Establishment.

28kW on the Alpha, and delivering around
11 litres/min, which the whole of
Europe, who have bought combi's of that
flowrate by the millions, deem
suitable for one shower.

Because that's what's available on the market.

Nonsense!! High and low flowrate combi's are on the market and now auto
duel flowrates too. They have the choice and those with the low
flowrates
deem then more than suitable for showers.

???

Twice that rate is
needed for a worthwhile shower.

You are prattling balls. Or are you a devil cult member wanting to rid
the
world of its natural, resources?

What on earth are you talking about?

You are a waster.

On Wed, 23 Jun 2004 16:16:58 +0100, "IMM" wrote:


"Andy Hall" wrote in message
.. .
On Wed, 23 Jun 2004 13:56:27 +0100, "IMM" wrote:



The whole thing can be avoided

What can be avoided? Auto 2 stage flowrates?

Yes. It's a completely unneccessary compromise

Prattling balls as usual. One of these NEVER runs out of hot water.

I know you are. The rate reduces to low level, an issue which can be
avoided.




No, because the space is not
significant

In most smallish Britush homes it is.

Perhaps there should be land value tax on airing cupboards to deal
with this.


and it doesn't look like a
school boiler house.

It does.

You're suggesting putting a large box

Not large.

weighing over 130kg

Weight doesn't matter as you don't lift it to have hot water.




on the kitchen wall that even
then doesn't do the job
properly.

It more than does the job and NEVER runs out of hot water.

We already covered that point and the limitations.


Kitchen wall space in most homes is at far more premium
than the airing cupboard.

So you say. It can go under the stairs, in the loft, etc.

or even the airing cupboard....



I believe in the performance they deliver.
You are the one quoting, and
believing brochures, not me.

I pointed out the areas where the
brochures conveniently avoid
mentioning

I said "I believe in the performance
they deliver" and they deliver.

I believe in a few things as well, but
not generally not from glossy
brochures.

Read back on the thread. You believe the Potterrton glossy on what is a
combi rather than the Builing Research Establishment.

I think that the boot is on the other foot.




What on earth are you talking about?

You are a waster.

I think that that is the pot calling the kettle black
..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Wed, 23 Jun 2004 16:16:58 +0100, "IMM" wrote:


"Andy Hall" wrote in message
.. .
On Wed, 23 Jun 2004 13:56:27 +0100, "IMM" wrote:



The whole thing can be avoided

What can be avoided? Auto 2 stage flowrates?

Yes. It's a completely unneccessary compromise

Prattling balls as usual. One of
these NEVER runs out of hot water.

I know you are. The rate reduces to
low level, an issue which can be
avoided.

Yes you are right, a 60kW combi would solve the problem and still within the
capacity of the smallest domestic gas supply.

No, because the space is not
significant

In most smallish British homes it is.

Perhaps there should be land value
tax on airing cupboards to deal
with this.

That may help. But as an airing cupboard is not land, it is difficult to
tax it.

and it doesn't look like a
school boiler house.

It does.

You're suggesting putting a large box

Not large.

weighing over 130kg

Weight doesn't matter as you don't lift it to have hot water.

on the kitchen wall that even
then doesn't do the job
properly.

It more than does the job and
NEVER runs out of hot water.

We already covered that point
and the limitations.

No limitations. It NEVER runs out of hot water.

Kitchen wall space in most homes is at far more premium
than the airing cupboard.

So you say. It can go under the stairs, in the loft, etc.

or even the airing cupboard....

No. as it take up needed space in there. Even if it was in the cupboard it
would only be on a back wall taking little space compared to a large
cylinder.

I believe in the performance they deliver.
You are the one quoting, and
believing brochures, not me.

I pointed out the areas where the
brochures conveniently avoid
mentioning

I said "I believe in the performance
they deliver" and they deliver.

I believe in a few things as well, but
not generally not from glossy
brochures.

Read back on the thread. You believe the Potterrton glossy on what is a
combi rather than the Builing Research Establishment.

I think that the boot is on the other foot.

Yes, my foot.

What on earth are you talking about?

You are a waster.

I think that that is the pot calling the kettle black
.andy

You are mad

On Wed, 23 Jun 2004 17:21:07 +0100, "IMM" wrote:


Yes you are right, a 60kW combi would solve the problem and still within the
capacity of the smallest domestic gas supply.

I understood that a domestic gas supply will deliver 62kW. It
doesn't leave much, does it......


In most smallish British homes it is.

Perhaps there should be land value
tax on airing cupboards to deal
with this.

That may help. But as an airing cupboard is not land, it is difficult to
tax it.

I am sure that you would find a way if you could.





No limitations. It NEVER runs out of hot water.

It drops to 11lpm. That's a BIG limitation.


Kitchen wall space in most homes is at far more premium
than the airing cupboard.

So you say. It can go under the stairs, in the loft, etc.

or even the airing cupboard....

No. as it take up needed space in there. Even if it was in the cupboard it
would only be on a back wall taking little space compared to a large
cylinder.

????

The space would be the same as a cylinder and equivalent boiler unless
you have a way to compress water. If you have, I would patent it
quickly.



..andy

To email, substitute .nospam with .gl

On Tue, 22 Jun 2004 22:36:19 +0100, Andy Hall wrote:

On 22 Jun 2004 05:42:56 -0700, (timegoesby)
wrote:



I have been assessing this Alpha combi and the new Powermax, as I like
packaged heating and hot water. I find these idiot proof as I don't
have to think out the system or control wiring. The Alpha is indeed a
two stage flow combi, so you never run out of hot water. I confirmed
this with Alpha. The Powermaxes have large storage unvented vessels
which make it unlikly to run out of hot water. The reheating times on
both are very good, which leads me to believe they will be reheating
water fast as you use it. This very fast reheating must extend the
cylinder size as such.

Be careful on that. It can only, by definition heat the water as
rapidly as the energy going in - in this case 25kW - not very
exciting. If the cylinder runs out of hot water, it is going to give
a fairly poor performance equivalent to a low to mid range combi.

There is no functional difference between the Potterton product and a
standard boiler plus fast recover cylinder.

The only reason it can claim to have "continuous" hot water is on the
basis that the cylinder doesn't run out. It certainly is not
heating the water as fast as it is being used. 30-48lpm needs more
than 25kW to provide it. The manufacturer does not state the
temperature rise in these figures either which suggests some
"marketing" of the figures.



If they can make the claim that such a unit provides 'continuous' HW then
that term could (equally misleadingly) be applied to any modern
conventional heating system with stored HW.

The limiting factor is likely to be the heat transfer rate between the
primary and the stored HW.

The key question (after dismissing the disingenuous claims) is whether
a) There is enough energy stored and added during the time of the
largest demand. (probably one large hot bath full).
b) That system is cabable of regenerating within a short enough time that
a series of largish demands can be met.

The only advantages I can see for a one box approach (other than saving
installer labour) are

a) The system might be able to sense that a demand is occuring and respond
more promptly than a conventional system. A typical conventional system
clocks the fact that a bath has been runn in a few minutes, so the extra
is not that great.

b) The store can be run hotter than would be prudent in a conventional
system. Again the difference beween storing at 80C v.60C is only
percentages rather than a factor. Also there are draw backs with a hotter
store.
1) The heat losses from the store must be higher and there may well be
_less_ room for insulation.
2) The HW output must be blended to prevent a low flow rate demand producing
hazardously hot water.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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

"Ed Sirett" wrote in message
news
On Tue, 22 Jun 2004 22:36:19 +0100, Andy Hall wrote:

On 22 Jun 2004 05:42:56 -0700, (timegoesby)
wrote:



I have been assessing this Alpha combi and the new Powermax, as I like
packaged heating and hot water. I find these idiot proof as I don't
have to think out the system or control wiring. The Alpha is indeed a
two stage flow combi, so you never run out of hot water. I confirmed
this with Alpha. The Powermaxes have large storage unvented vessels
which make it unlikly to run out of hot water. The reheating times on
both are very good, which leads me to believe they will be reheating
water fast as you use it. This very fast reheating must extend the
cylinder size as such.

Be careful on that. It can only, by definition heat the water as
rapidly as the energy going in - in this case 25kW - not very
exciting. If the cylinder runs out of hot water, it is going to give
a fairly poor performance equivalent to a low to mid range combi.

There is no functional difference between the Potterton product and a
standard boiler plus fast recover cylinder.

The only reason it can claim to have "continuous" hot water is on the
basis that the cylinder doesn't run out. It certainly is not
heating the water as fast as it is being used. 30-48lpm needs more
than 25kW to provide it. The manufacturer does not state the
temperature rise in these figures either which suggests some
"marketing" of the figures.



If they can make the claim that such a unit provides 'continuous' HW then
that term could (equally misleadingly) be applied to any modern
conventional heating system with stored HW.

The limiting factor is likely to be the heat transfer rate between the
primary and the stored HW.

The key question (after dismissing the disingenuous claims) is whether
a) There is enough energy stored and added during the time of the
largest demand. (probably one large hot bath full).
b) That system is cabable of regenerating within a short enough time that
a series of largish demands can be met.

The only advantages I can see for a one box approach (other than saving
installer labour) are

a) The system might be able to sense that a demand is occuring and respond
more promptly than a conventional system. A typical conventional system
clocks the fact that a bath has been runn in a few minutes, so the extra
is not that great.

b) The store can be run hotter than would be prudent in a conventional
system. Again the difference beween storing at 80C v.60C is only
percentages rather than a factor. Also there are draw backs with a hotter
store.
1) The heat losses from the store must be higher and there may well be
_less_ room for insulation.
2) The HW output must be blended to prevent a low flow rate demand
producing
hazardously hot water.



A very pertinent factor will be the maintenance costs viz all the parts of a
"box" will be sourced via the manufacturer at a premium. Seperate boiler and
cylinder with controls will be available from "any good store" at
competitive prices

"Andy Hall" wrote in message
...
On Wed, 23 Jun 2004 17:21:07 +0100, "IMM" wrote:


Yes you are right, a 60kW combi would solve the problem and still within
the
capacity of the smallest domestic gas supply.

I understood that a domestic gas supply will deliver 62kW. It
doesn't leave much, does it......

Still within.

In most smallish British homes it is.

Perhaps there should be land value
tax on airing cupboards to deal
with this.

That may help. But as an airing cupboard is not land, it is difficult to
tax it.

I am sure that you would find a way if you could.

No., just tax land.

No limitations. It NEVER runs out of hot water.

It drops to 11lpm. That's a BIG limitation.

It is not. You ALWAYS have hot water. The 1st stage give v good
flowrates.

Kitchen wall space in most homes is at far more premium
than the airing cupboard.

So you say. It can go under the stairs, in the loft, etc.

or even the airing cupboard....

No. as it take up needed space in there. Even if it was in the cupboard
it
would only be on a back wall taking little space compared to a large
cylinder.

????

The space would be the same
as a cylinder

No it would not be. A cylinder takes up lots of space.

"Ed Sirett" wrote in message
news
The only advantages I can see for a one box approach (other than saving
installer labour) are

a) The system might be able to sense that a demand is occuring and respond
more promptly than a conventional system. A typical conventional system
clocks the fact that a bath has been runn in a few minutes, so the extra
is not that great.

b) The store can be run hotter than would be prudent in a conventional
system. Again the difference beween storing at 80C v.60C is only
percentages rather than a factor. Also there are draw backs with a hotter
store.
1) The heat losses from the store must be higher and there may well be
_less_ room for insulation.
2) The HW output must be blended to prevent a low flow rate demand
producing
hazardously hot water.

You are having a laugh of course. Only TWO advantages. Look harder please.

On Wed, 23 Jun 2004 22:13:46 +0100, "IMM" wrote:


"Andy Hall" wrote in message
.. .
On Wed, 23 Jun 2004 17:21:07 +0100, "IMM" wrote:


Yes you are right, a 60kW combi would solve the problem and still within
the
capacity of the smallest domestic gas supply.

I understood that a domestic gas supply will deliver 62kW. It
doesn't leave much, does it......

Still within.

Hardly a good design to sail it so close to the wind. Not the design
approach of a professional engineer.




No limitations. It NEVER runs out of hot water.

It drops to 11lpm. That's a BIG limitation.

It is not.

On that we'll have to agree to differ.

You ALWAYS have hot water. The 1st stage give v good
flowrates.

For a while.



would only be on a back wall taking little space compared to a large
cylinder.

That would be because.... hmmm..... let me see..... ah yes, the stored
water volume is smaller.



????

The space would be the same
as a cylinder

No it would not be. A cylinder takes up lots of space.


Groan.....



..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Wed, 23 Jun 2004 22:13:46 +0100, "IMM" wrote:


"Andy Hall" wrote in message
.. .
On Wed, 23 Jun 2004 17:21:07 +0100, "IMM" wrote:


Yes you are right, a 60kW combi would solve the problem and still
within
the
capacity of the smallest domestic gas supply.

I understood that a domestic gas supply will deliver 62kW. It
doesn't leave much, does it......

Still within.

Hardly a good design to sail it so close to the wind.

Still within. A domestic meter can take 100% overload. The occasional blip
over is no problem. Didn't know that did you.

No limitations. It NEVER runs out of hot water.

It drops to 11lpm. That's a BIG limitation.

It is not.

On that we'll have to agree to differ.

No. Me thinking you haven't a clue.

You ALWAYS have hot water. The 1st stage give v good
flowrates.

For a while.

Enough for normal domestic use and then no water run out at all. Brilliant
eh!

would only be on a back wall taking
little space compared to a large
cylinder.

That would be because.... hmmm..... let
me see..... ah yes, the stored
water volume is smaller.

Very clever!! 10/10. Another point is that the box is desighned to save
space too. So overall only 5/10.

????

The space would be the same
as a cylinder

No it would not be. A cylinder takes up lots of space.

Groan.....

Some do that as well.

"John" wrote in message
...

"Ed Sirett" wrote in message
news
On Tue, 22 Jun 2004 22:36:19 +0100, Andy Hall wrote:

On 22 Jun 2004 05:42:56 -0700, (timegoesby)
wrote:



I have been assessing this Alpha combi and the new Powermax, as I like
packaged heating and hot water. I find these idiot proof as I don't
have to think out the system or control wiring. The Alpha is indeed a
two stage flow combi, so you never run out of hot water. I confirmed
this with Alpha. The Powermaxes have large storage unvented vessels
which make it unlikly to run out of hot water. The reheating times on
both are very good, which leads me to believe they will be reheating
water fast as you use it. This very fast reheating must extend the
cylinder size as such.

Be careful on that. It can only, by definition heat the water as
rapidly as the energy going in - in this case 25kW - not very
exciting. If the cylinder runs out of hot water, it is going to give
a fairly poor performance equivalent to a low to mid range combi.

There is no functional difference between the Potterton product and a
standard boiler plus fast recover cylinder.

The only reason it can claim to have "continuous" hot water is on the
basis that the cylinder doesn't run out. It certainly is not
heating the water as fast as it is being used. 30-48lpm needs more
than 25kW to provide it. The manufacturer does not state the
temperature rise in these figures either which suggests some
"marketing" of the figures.



If they can make the claim that such a unit provides 'continuous' HW
then
that term could (equally misleadingly) be applied to any modern
conventional heating system with stored HW.

The limiting factor is likely to be the heat transfer rate between the
primary and the stored HW.

The key question (after dismissing the disingenuous claims) is whether
a) There is enough energy stored and added during the time of the
largest demand. (probably one large hot bath full).
b) That system is cabable of regenerating within a short enough time
that
a series of largish demands can be met.

The only advantages I can see for a one box approach (other than saving
installer labour) are

a) The system might be able to sense that a demand is occuring and
respond
more promptly than a conventional system. A typical conventional system
clocks the fact that a bath has been runn in a few minutes, so the extra
is not that great.

b) The store can be run hotter than would be prudent in a conventional
system. Again the difference beween storing at 80C v.60C is only
percentages rather than a factor. Also there are draw backs with a
hotter
store.
1) The heat losses from the store must be higher and there may well be
_less_ room for insulation.
2) The HW output must be blended to prevent a low flow rate demand
producing
hazardously hot water.

A very pertinent factor will be the maintenance costs viz all the parts of
a
"box" will be sourced via the manufacturer at a premium. Seperate boiler
and
cylinder with controls will be available from "any good store" at
competitive prices

It is not a pertinent factor. Boilers don't brake down every month.

On Wed, 23 Jun 2004 22:44:21 +0100, "IMM" wrote:




Still within. A domestic meter can take 100% overload. The occasional blip
over is no problem. Didn't know that did you.

Obviously system components are designed with a margin. It remains
bad practice to use them close to and certainly beyond their
specification.



Enough for normal domestic use and then no water run out at all. Brilliant
eh!

For those with low expectations perhaps/



would only be on a back wall taking
little space compared to a large
cylinder.

That would be because.... hmmm..... let
me see..... ah yes, the stored
water volume is smaller.

Very clever!! 10/10. Another point is that the box is desighned to save
space too. So overall only 5/10.

So it's a T.A.R.D.I.S as well is it?


????

The space would be the same
as a cylinder

No it would not be. A cylinder takes up lots of space.

Groan.....

Some do that as well.


..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Wed, 23 Jun 2004 22:44:21 +0100, "IMM" wrote:




Still within. A domestic meter can take 100% overload. The occasional
blip
over is no problem. Didn't know that did you.

Obviously system components are designed with a margin. It remains
bad practice to use them close to and certainly beyond their
specification.

A U6 212 cu/ft per/hr meter could handle 350 cu/foot no problem at all, and
were installed to do so, despite having 212 on the front. The limiting
factor was the supply pipe, which being 1" should deliver 350 no problem
anyhow.

Enough for normal domestic use and
then no water run out at all. Brilliant
eh!

For those with low expectations perhaps/

I can't comment on your devil doomsday wishes.

would only be on a back wall taking
little space compared to a large
cylinder.

That would be because.... hmmm..... let
me see..... ah yes, the stored
water volume is smaller.

Very clever!! 10/10. Another point is that the box is designed to save
space too. So overall only 5/10.

So it's a T.A.R.D.I.S as well is it?

Sort of.

On Wed, 23 Jun 2004 23:32:52 +0100, "IMM" wrote:



A U6 212 cu/ft per/hr meter could handle 350 cu/foot no problem at all, and
were installed to do so, despite having 212 on the front. The limiting
factor was the supply pipe, which being 1" should deliver 350 no problem
anyhow.

Could you produce a letter from Transco approving this as a working
specification?



Enough for normal domestic use and
then no water run out at all. Brilliant
eh!

For those with low expectations perhaps/

I can't comment on your devil doomsday wishes.

????



would only be on a back wall taking
little space compared to a large
cylinder.

That would be because.... hmmm..... let
me see..... ah yes, the stored
water volume is smaller.

Very clever!! 10/10. Another point is that the box is designed to save
space too. So overall only 5/10.

So it's a T.A.R.D.I.S as well is it?

Sort of.


Ahh.. I thought so...


..andy

To email, substitute .nospam with .gl

IMM wrote:

In the winter, that is going to be a feeble 6.6L/min of water if you
want it at the original 65 deg C...


Where do they come from? A shower is approx 43C.

Simple maths...

You start off with the stored water in the "system in a box" boiler at
65 deg and ample flow rate. As it runs out you revert to instant water
heating. That can sustain the temperature at the above mentioned 6.6
lpm, or if you accept a fall in temp you can have the 11 lpm flowrate.
Either will result in a significant drop in flow rate at the tap (i.e.
well under half of what you started out with). If you have a non
thermostatic shower you are likely to get you gonads frozen off.

--
Cheers,

John.

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

"John Rumm" wrote in message
...
IMM wrote:

In the winter, that is going to be a feeble 6.6L/min of water if you
want it at the original 65 deg C...


Where do they come from? A shower is approx 43C.

Simple maths...

You start off with the stored water in the "system in a box" boiler at
65 deg and ample flow rate. As it runs out you revert to instant water
heating.

The boiler reheats the cylinder as hot water is being drawn-off.

That can sustain the temperature at the above mentioned 6.6
lpm, or if you accept a fall in temp you can have the 11 lpm flowrate.
Either will result in a significant drop in flow rate at the tap (i.e.
well under half of what you started out with). If you have a non
thermostatic shower you are likely to get you gonads frozen off.

I see no maths only figures plucked from the air.

"Andy Hall" wrote in message
...

On Wed, 23 Jun 2004 23:32:52 +0100, "IMM" wrote:

A U6 212 cu/ft per/hr meter could handle 350 cu/foot no problem at all,
and
were installed to do so, despite having 212 on the front. The limiting
factor was the supply pipe, which being 1" should deliver 350 no problem
anyhow.

Could you produce a letter from Transco approving this as a working
specification?

No. You have to take a professionals word for it.

Enough for normal domestic use and
then no water run out at all. Brilliant
eh!

For those with low expectations perhaps/

I can't comment on your devil doomsday wishes.

????

would only be on a back wall taking
little space compared to a large
cylinder.

That would be because.... hmmm..... let
me see..... ah yes, the stored
water volume is smaller.

Very clever!! 10/10. Another point is that the box is designed to
save
space too. So overall only 5/10.

So it's a T.A.R.D.I.S as well is it?

Sort of.


Ahh.. I thought so...

The penny may be droppping.

On Thu, 24 Jun 2004 01:12:09 +0100, "IMM" wrote:


"John Rumm" wrote in message
. ..
IMM wrote:

In the winter, that is going to be a feeble 6.6L/min of water if you
want it at the original 65 deg C...


Where do they come from? A shower is approx 43C.

Simple maths...

You start off with the stored water in the "system in a box" boiler at
65 deg and ample flow rate. As it runs out you revert to instant water
heating.

The boiler reheats the cylinder as hot water is being drawn-off.

That can sustain the temperature at the above mentioned 6.6
lpm, or if you accept a fall in temp you can have the 11 lpm flowrate.
Either will result in a significant drop in flow rate at the tap (i.e.
well under half of what you started out with). If you have a non
thermostatic shower you are likely to get you gonads frozen off.

I see no maths only figures plucked from the air.


That is generally your modus operandi, yes....


..andy

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