Many thanks to Andy Hall and others for their help earlier this year on the
design of my new plumbing system (http://tinyurl.com/3pwck etc.).
Unfortunately, thanks to a few months illness, I'm still at it - with a few
issues to resolve.

A question regarding an unvented domestic hot water system: Cambridge Water
tested my incoming main supply and informed me that the pressure = 2.8 bar
and the flow rate = 25 litres per minute. Is this sufficiently high for an
unvented supply feeding a family home containing two power showers, a bath,
five sinks, three toilets, a washing machine and a dishwasher?

My feeling is that it isn't. At worst, I would guess that only one shower
and the bath would be running concurrently. Even so, a power shower consumes
15 lpm and a bath consumes 20 lpm.

Is there any way around this problem? A pump and hydraulic accumulator
sounds expensive. Due to a loft conversion, there is not any convenient
space for a cistern, although I'm thinking that I may have to create some...

[For information, the hot water will be heated indirectly in a 250 litre
tank by a condensing boiler. The mains supply pressure will be reduced (to 2
bar?) by a water softener, although a "high flow" softener, such as the
Kinetico 2020c HF, will be fitted to minimise this problem.]

Presumably the central heating could operate as a sealed system, even if the
hot water tank is vented?

TIA

On Wed, 6 Oct 2004 00:40:02 +0100, "John Aston"
wrote:

Many thanks to Andy Hall and others for their help earlier this year on the
design of my new plumbing system (http://tinyurl.com/3pwck etc.).
Unfortunately, thanks to a few months illness, I'm still at it - with a few
issues to resolve.

A question regarding an unvented domestic hot water system: Cambridge Water
tested my incoming main supply and informed me that the pressure = 2.8 bar
and the flow rate = 25 litres per minute. Is this sufficiently high for an
unvented supply feeding a family home containing two power showers, a bath,
five sinks, three toilets, a washing machine and a dishwasher?

My feeling is that it isn't. At worst, I would guess that only one shower
and the bath would be running concurrently. Even so, a power shower consumes
15 lpm and a bath consumes 20 lpm.

I think that it's marginal. The static pressure is reasonable but
not exciting. Flow rate isn't brilliant but not at a level where the
supplier is likely to do anything for nothing.

You could put flow restrictors on the feeds to the bath to protect the
flow to the shower, and if you don't mind reasonable pressure but not
high shower flow, you could do the shame with the showers and perhaps
cut them to 10-12lpm.

At these levels I think I'd try to do something about it.


Is there any way around this problem? A pump and hydraulic accumulator
sounds expensive. Due to a loft conversion, there is not any convenient
space for a cistern, although I'm thinking that I may have to create some...

Don't forget that there are tanks available in different shapes and
sizes from Polytank and that one can always link more than one
together if it helps with the nature of the space available.

About the only other option is to look into having a larger diameter
service pipe installed from the road main into the house. THis can
be disruptive and not inexpensive of course.



[For information, the hot water will be heated indirectly in a 250 litre
tank by a condensing boiler. The mains supply pressure will be reduced (to 2
bar?) by a water softener, although a "high flow" softener, such as the
Kinetico 2020c HF, will be fitted to minimise this problem.]

Certainly a high flow type should be used..



Presumably the central heating could operate as a sealed system, even if the
hot water tank is vented?


Yes it can.



TIA



..andy

To email, substitute .nospam with .gl

Andy Hall wrote in message
...
On Wed, 6 Oct 2004 00:40:02 +0100, "John Aston"
wrote:

snip

Is there any way around this problem? A pump and hydraulic accumulator
sounds expensive. Due to a loft conversion, there is not any convenient
space for a cistern, although I'm thinking that I may have to create
some...

Don't forget that there are tanks available in different shapes and
sizes from Polytank and that one can always link more than one
together if it helps with the nature of the space available.

About the only other option is to look into having a larger diameter
service pipe installed from the road main into the house. THis can
be disruptive and not inexpensive of course.


Hi, Andy.

Unfortunately, I have already replaced the service pipe with a new 32mm
diameter pipe. Cambridge Water tell me that they can't do anything about the
flow/pressure "because the supply is fed directly from a reservoir".

Space in my loft is very limited, but I do have basement space so I could
get an accumulator.

GAH make a "Dualstream" accumulator but you have to buy their rebadged
Ariston unvented hot water cylinder with it. I don't know anything about the
quality of Ariston.

For a 300 litre accumulator and 300 litre cylinder the list price is £2112
(less 40% from a distributor I'm told!). The 300 litre accumulator is 5'2"
high and almost 2' diameter so it takes up a lot of room.

I suppose that I'll have to compare the Dualstream cost with a "cistern and
pump" solution and take a view on it.

(Sorry - Posted this reply using my wife's newsgroup reader by mistake...)

Andy Hall wrote in message
...
On Wed, 6 Oct 2004 00:40:02 +0100, "John Aston"
wrote:

snip

Is there any way around this problem? A pump and hydraulic accumulator
sounds expensive. Due to a loft conversion, there is not any convenient
space for a cistern, although I'm thinking that I may have to create
some...

Don't forget that there are tanks available in different shapes and
sizes from Polytank and that one can always link more than one
together if it helps with the nature of the space available.

About the only other option is to look into having a larger diameter
service pipe installed from the road main into the house. THis can
be disruptive and not inexpensive of course.


Hi, Andy.

Unfortunately, I have already replaced the service pipe with a new 32mm
diameter pipe. Cambridge Water tell me that they can't do anything about the
flow/pressure "because the supply is fed directly from a reservoir".

Space in my loft is very limited, but I do have basement space so I could
get an accumulator.

GAH make a "Dualstream" accumulator but you have to buy their rebadged
Ariston unvented hot water cylinder with it. I don't know anything about the
quality of Ariston.

For a 300 litre accumulator and 300 litre cylinder the list price is £2112
(less 40% from a distributor I'm told!). The 300 litre accumulator is 5'2"
high and almost 2' diameter so it takes up a lot of room.

I suppose that I'll have to compare the Dualstream cost with a "cistern and
pump" solution and take a view on it.

"John Aston" wrote in message
.. .
(Sorry - Posted this reply using my wife's newsgroup reader by mistake...)

Andy Hall wrote in message
...
On Wed, 6 Oct 2004 00:40:02 +0100, "John Aston"
wrote:

snip

Is there any way around this problem? A pump and hydraulic accumulator
sounds expensive. Due to a loft conversion, there is not any convenient
space for a cistern, although I'm thinking that I may have to create
some...

Don't forget that there are tanks available in different shapes and
sizes from Polytank and that one can always link more than one
together if it helps with the nature of the space available.

About the only other option is to look into having a larger diameter
service pipe installed from the road main into the house. THis can
be disruptive and not inexpensive of course.


Hi, Andy.

Unfortunately, I have already replaced the service pipe with a new 32mm
diameter pipe. Cambridge Water tell me that they can't do anything about
the
flow/pressure "because the supply is fed directly from a reservoir".

Space in my loft is very limited, but I do have basement space so I could
get an accumulator.

GAH make a "Dualstream" accumulator but you have to buy their rebadged
Ariston unvented hot water cylinder with it. I don't know anything about
the
quality of Ariston.

For a 300 litre accumulator and 300 litre cylinder the list price is £2112
(less 40% from a distributor I'm told!). The 300 litre accumulator is 5'2"
high and almost 2' diameter so it takes up a lot of room.

I suppose that I'll have to compare the Dualstream cost with a "cistern
and
pump" solution and take a view on it.

I assume you haven't bought any equipment yet. In your situation which I
assume you have 1 bath and two showers, and I would go:

1. Combi boiler (to do the two showers only)
2. A "combination" cylinder with quick recovery coil. (cold tank and hot
cylinder all in one space saving unit). This operates at low pressure
http://www.rcmgroup.co.uk/specialized.htm RCM will make a large cold tank
section for you. They will ake the hot and cold section sizes to order.

The CH side of the combi acts as a normal system boiler heating the cylinder
and CH. The cylinder does the bath and therest of the house to give good
fillups. The water side of the combi only does high pressure showers.
Something like an Alpha CB50, W-B Greenstar high flow condensing combi would
do. The W-B Greenstar 40kW model can deliver 16 litres/min and you need to
add cold to the showers, so a decent shower had if two on at the same time.
This approach is cost effective and no power shower pump used.

Another approach is a "combinatiuon" cylinder witha quick recovery coil
serving all hot outlets and cold for showers using a conventional power
shower pump for then showers and a condesning system boiler. Use a Torbeck
ball valve in the cold section and 22mm cold mains directly to it to give
repaid fills ups. The Torbeck is either on or off.

Will you really have the bath filling and a shower on at the same time? A
relative has had a single shower power shower pump serving two showers for
10 years. Not once has two showers been on at the same time.

On Wed, 06 Oct 2004 00:40:02 +0100, John Aston wrote:

Many thanks to Andy Hall and others for their help earlier this year on the
design of my new plumbing system (http://tinyurl.com/3pwck etc.).
Unfortunately, thanks to a few months illness, I'm still at it - with a few
issues to resolve.

A question regarding an unvented domestic hot water system: Cambridge Water
tested my incoming main supply and informed me that the pressure = 2.8 bar
and the flow rate = 25 litres per minute. Is this sufficiently high for an
unvented supply feeding a family home containing two power showers, a bath,
five sinks, three toilets, a washing machine and a dishwasher?

My feeling is that it isn't. At worst, I would guess that only one shower
and the bath would be running concurrently. Even so, a power shower consumes
15 lpm and a bath consumes 20 lpm.

Is there any way around this problem? A pump and hydraulic accumulator
sounds expensive. Due to a loft conversion, there is not any convenient
space for a cistern, although I'm thinking that I may have to create some...

[For information, the hot water will be heated indirectly in a 250 litre
tank by a condensing boiler. The mains supply pressure will be reduced (to 2
bar?) by a water softener, although a "high flow" softener, such as the
Kinetico 2020c HF, will be fitted to minimise this problem.]

Presumably the central heating could operate as a sealed system, even if the
hot water tank is vented?

Given that you want to soften the water I strongly think that a pumped
storage cistern approach will be best. I'm really surprised that 2.8 bar
static on 32mm (25mm inside) MDPE pipe gives only 25lpm.
This implies that the supply in the road is somewhat restrictive. Did the
Water Company section in the road get replaced all the way to the main? or
just to the meter? or just to the property boundary.

How was the 25 lpm derived?


The are all sorts of tanks for using the eaves and apex of roof spaces if
that is an issue.

--
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 Wed, 06 Oct 2004 00:40:02 +0100, John Aston wrote:

Many thanks to Andy Hall and others for their help earlier this year on
the
design of my new plumbing system (http://tinyurl.com/3pwck etc.).
Unfortunately, thanks to a few months illness, I'm still at it - with a
few
issues to resolve.

A question regarding an unvented domestic hot water system: Cambridge
Water
tested my incoming main supply and informed me that the pressure = 2.8
bar
and the flow rate = 25 litres per minute. Is this sufficiently high for
an
unvented supply feeding a family home containing two power showers, a
bath,
five sinks, three toilets, a washing machine and a dishwasher?

My feeling is that it isn't. At worst, I would guess that only one
shower
and the bath would be running concurrently. Even so, a power shower
consumes
15 lpm and a bath consumes 20 lpm.

Is there any way around this problem? A pump and hydraulic accumulator
sounds expensive. Due to a loft conversion, there is not any convenient
space for a cistern, although I'm thinking that I may have to create
some...

[For information, the hot water will be heated indirectly in a 250 litre
tank by a condensing boiler. The mains supply pressure will be reduced
(to 2
bar?) by a water softener, although a "high flow" softener, such as the
Kinetico 2020c HF, will be fitted to minimise this problem.]

Presumably the central heating could operate as a sealed system, even if
the
hot water tank is vented?

Given that you want to soften the water I strongly think that a pumped
storage cistern approach will be best. I'm really surprised that 2.8 bar
static on 32mm (25mm inside) MDPE pipe gives only 25lpm.
This implies that the supply in the road is somewhat restrictive.

Is the stop cock a full one?

On Wed, 6 Oct 2004 12:36:40 +0100, "John Aston"
wrote:


Hi, Andy.

Unfortunately, I have already replaced the service pipe with a new 32mm
diameter pipe. Cambridge Water tell me that they can't do anything about the
flow/pressure "because the supply is fed directly from a reservoir".

This rather suggests that their main is limited.

The best thing that you can do is to look at all the components after
the service pipe. e.g. stop cock full bore lever ball valve, 22mm
pipe internally to key points or 28mm for anything of any length,
avoid too many bends.



Space in my loft is very limited, but I do have basement space so I could
get an accumulator.

GAH make a "Dualstream" accumulator but you have to buy their rebadged
Ariston unvented hot water cylinder with it. I don't know anything about the
quality of Ariston.

For a 300 litre accumulator and 300 litre cylinder the list price is £2112
(less 40% from a distributor I'm told!). The 300 litre accumulator is 5'2"
high and almost 2' diameter so it takes up a lot of room.

I suppose that I'll have to compare the Dualstream cost with a "cistern and
pump" solution and take a view on it.


This is an expensive hobby.

I think that IMM's idea of some storage above the HW cylinder is
interesting, if you have the height. However, be careful about
making the HW cylinder too small because you risk running out of hot
water for the bath.

However......


I don't subscribe to the notion of a combi with small store running
two showers and certainly not a shower and a bath for three reasons:

- The amount of stored energy is small and once it runs out, the
performance is very poor.

- The hot water is mixed with very little cold in the winter, so the
run time will be quite short.

- You are still governed by the total delivery of water from the main.

I think that I would try to look for different ways to store cold
water high up before getting into accumulators.

If it really doesn't add up, then this may be the sensible option
though.




..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Wed, 6 Oct 2004 12:36:40 +0100, "John Aston"
wrote:


Hi, Andy.

Unfortunately, I have already replaced the service pipe with a new 32mm
diameter pipe. Cambridge Water tell me that they can't do anything about
the
flow/pressure "because the supply is fed directly from a reservoir".

This rather suggests that their main is limited.

The best thing that you can do is to look at all the components after
the service pipe. e.g. stop cock full bore lever ball valve, 22mm
pipe internally to key points or 28mm for anything of any length,
avoid too many bends.



Space in my loft is very limited, but I do have basement space so I could
get an accumulator.

GAH make a "Dualstream" accumulator but you have to buy their rebadged
Ariston unvented hot water cylinder with it. I don't know anything about
the
quality of Ariston.

For a 300 litre accumulator and 300 litre cylinder the list price is
£2112
(less 40% from a distributor I'm told!). The 300 litre accumulator is
5'2"
high and almost 2' diameter so it takes up a lot of room.

I suppose that I'll have to compare the Dualstream cost with a "cistern
and
pump" solution and take a view on it.


This is an expensive hobby.

I think that IMM's idea of some storage above the HW cylinder is
interesting, if you have the height. However, be careful about
making the HW cylinder too small because you risk running out of hot
water for the bath.

However......

snip tripe

And you were doing so well up until now. 5/10

IMM wrote in message ...

I assume you haven't bought any equipment yet.

That's correct.

In your situation which I
assume you have 1 bath and two showers, and I would go:

1. Combi boiler (to do the two showers only)
2. A "combination" cylinder with quick recovery coil. (cold tank and hot
cylinder all in one space saving unit). This operates at low pressure
http://www.rcmgroup.co.uk/specialized.htm RCM will make a large cold tank
section for you. They will ake the hot and cold section sizes to order.

The CH side of the combi acts as a normal system boiler heating the
cylinder
and CH. The cylinder does the bath and therest of the house to give good
fillups. The water side of the combi only does high pressure showers.
Something like an Alpha CB50, W-B Greenstar high flow condensing combi
would
do. The W-B Greenstar 40kW model can deliver 16 litres/min and you need
to
add cold to the showers, so a decent shower had if two on at the same
time.
This approach is cost effective and no power shower pump used.


Sorry, I'm misunderstanding something here. I thought that the total flow
rate was limited by the available flow rate at the incoming service pipe. Or
is hot water stored in the combi boiler and pumped to the shower on demand?
Apologies for my ignorance.


Will you really have the bath filling and a shower on at the same time?
A
relative has had a single shower power shower pump serving two showers for
10 years. Not once has two showers been on at the same time.


I would like to budget for a bath and shower that are on simultaneously. I
have a large family.

"John Aston" wrote in message
.. .

IMM wrote in message
...

I assume you haven't bought any equipment yet.

That's correct.

In your situation which I
assume you have 1 bath and two showers, and I would go:

1. Combi boiler (to do the two showers only)
2. A "combination" cylinder with quick recovery coil. (cold tank and
hot
cylinder all in one space saving unit). This operates at low pressure
http://www.rcmgroup.co.uk/specialized.htm RCM will make a large cold
tank
section for you. They will ake the hot and cold section sizes to
order.

The CH side of the combi acts as a normal system boiler heating the
cylinder
and CH. The cylinder does the bath and therest of the house to give
good
fillups. The water side of the combi only does high pressure showers.
Something like an Alpha CB50, W-B Greenstar high flow condensing combi
would
do. The W-B Greenstar 40kW model can deliver 16 litres/min and you need
to
add cold to the showers, so a decent shower had if two on at the same
time.
This approach is cost effective and no power shower pump used.


Sorry, I'm misunderstanding something here. I thought that the total flow
rate was limited by the available flow rate at the incoming service pipe.
Or
is hot water stored in the combi boiler and pumped to the shower on
demand?
Apologies for my ignorance.

Stored water in the combination cylinder for all the house giving a good
flow, which is not on the mains. The combi cylinder is the bottom right.
http://www.rcmgroup.co.uk/specialized.htm
The mains only supplying the two showers via the combi boiler giving high
pressure showers with a power shower pump. The Alpha CB50 is a stored water
combi, the Greenstar is not.

Will you really have the bath filling and a shower
on at the same time? A relative has had a single
shower power shower pump serving two showers for
10 years. Not once has two showers been on at the same time.

I would like to budget for a bath and shower that are
on simultaneously. I have a large family.

That is fine. Some people tend to oversize water systems. If one bath and
one shower simultaneously then the combination cylinder with a quick
recovery coil and a combi boiler doing only the showers is the way. I assume
the bath will be below or on the same level as the cylinder? If so, then no
problems.

Ed Sirett wrote in message
news
On Wed, 06 Oct 2004 00:40:02 +0100, John Aston wrote:

snip

A question regarding an unvented domestic hot water system: Cambridge
Water
tested my incoming main supply and informed me that the pressure = 2.8
bar
and the flow rate = 25 litres per minute. Is this sufficiently high for
an
unvented supply feeding a family home containing two power showers, a
bath,
five sinks, three toilets, a washing machine and a dishwasher?

snip

Given that you want to soften the water I strongly think that a pumped
storage cistern approach will be best.

Better than an accumulator?

I'm really surprised that 2.8 bar
static on 32mm (25mm inside) MDPE pipe gives only 25lpm.
This implies that the supply in the road is somewhat restrictive.

I wonder if the water meter could be resticting the flow significantly.

Did the Water Company section in the road get replaced all the way to the
main? or just to the meter? or just to the property boundary.

The 32mm MDPE pipe was laid by me from the water meter point at the boundary
of my property to the main stopcock in my house (a distance of 45m).

How was the 25 lpm derived?

Unfortunately I wasn't present when the Cambridge Water engineer came to
measure the flow rate, so I don't know how the figure of 25 lpm was derived.
My own test was very empirical - I switched off all water supplied to the
house and turned on the garden hose. The jet of water did not "feel" very
substantial, particularly if is to be shared among appliances.

The are all sorts of tanks for using the eaves and apex of roof spaces if
that is an issue.

Thanks. I'll look around.

"IMM" wrote in message
...

"John Aston" wrote in message
.. .

IMM wrote in message
...

I assume you haven't bought any equipment yet.

That's correct.

In your situation which I
assume you have 1 bath and two showers, and I would go:

1. Combi boiler (to do the two showers only)
2. A "combination" cylinder with quick recovery coil. (cold tank and
hot
cylinder all in one space saving unit). This operates at low pressure
http://www.rcmgroup.co.uk/specialized.htm RCM will make a large cold
tank
section for you. They will ake the hot and cold section sizes to
order.

The CH side of the combi acts as a normal system boiler heating the
cylinder
and CH. The cylinder does the bath and therest of the house to give
good
fillups. The water side of the combi only does high pressure showers.
Something like an Alpha CB50, W-B Greenstar high flow condensing combi
would
do. The W-B Greenstar 40kW model can deliver 16 litres/min and you
need
to
add cold to the showers, so a decent shower had if two on at the same
time.
This approach is cost effective and no power shower pump used.


Sorry, I'm misunderstanding something here. I thought that the total
flow
rate was limited by the available flow rate at the incoming service
pipe.
Or
is hot water stored in the combi boiler and pumped to the shower on
demand?
Apologies for my ignorance.

Stored water in the combination cylinder for all the house giving a good
flow, which is not on the mains. The combi cylinder is the bottom right.
http://www.rcmgroup.co.uk/specialized.htm
The mains only supplying the two showers via the combi boiler giving high
pressure showers with a power shower pump. The Alpha CB50 is a stored
water
combi, the Greenstar is not.

Will you really have the bath filling and a shower
on at the same time? A relative has had a single
shower power shower pump serving two showers for
10 years. Not once has two showers been on at the same time.

I would like to budget for a bath and shower that are
on simultaneously. I have a large family.

That is fine. Some people tend to oversize water systems. If one bath and
one shower simultaneously then the combination cylinder with a quick
recovery coil and a combi boiler doing only the showers is the way. I
assume
the bath will be below or on the same level as the cylinder? If so, then
no
problems.

Combination cylinders:
http://www.rcmgroup.co.uk/Direct&Indirect.htm

They have units with in litres:
hot : cold
115: 160
115: 228

The large cold storage means you can have a the cold section supplying the
hot and cold in the house and a 15mm pipe filling the unit. The showers are
via the combi.

"John Aston" wrote in message
.. .

Ed Sirett wrote in message
news
On Wed, 06 Oct 2004 00:40:02 +0100, John Aston wrote:

snip

A question regarding an unvented domestic hot water system: Cambridge
Water
tested my incoming main supply and informed me that the pressure = 2.8
bar
and the flow rate = 25 litres per minute. Is this sufficiently high
for
an
unvented supply feeding a family home containing two power showers, a
bath,
five sinks, three toilets, a washing machine and a dishwasher?

snip

Given that you want to soften the water I strongly think that a pumped
storage cistern approach will be best.

Better than an accumulator?


I think Ed means a basement located tank with a pressure pump doing all the
house, hot and cold. I prefer the combination cylinder.

I'm really surprised that 2.8 bar
static on 32mm (25mm inside) MDPE pipe gives only 25lpm.
This implies that the supply in the road is somewhat restrictive.

I wonder if the water meter could be resticting the flow significantly.

They sometimes do. Make sure you have a full bore 1/4 turn stop cock.

Did the Water Company section in the road get replaced all the way to
the
main? or just to the meter? or just to the property boundary.

The 32mm MDPE pipe was laid by me from the water meter point at the
boundary
of my property to the main stopcock in my house (a distance of 45m).

How was the 25 lpm derived?

Unfortunately I wasn't present when the Cambridge Water engineer came to
measure the flow rate, so I don't know how the figure of 25 lpm was
derived.
My own test was very empirical - I switched off all water supplied to the
house and turned on the garden hose. The jet of water did not "feel" very
substantial, particularly if is to be shared among appliances.

The garden hose is usually at the end a run in 15 mm pipe running through
double check valve. If you can, take a large bore hose directly from the
stop cock and measure that. If it is substantially better then run 22mm to
any mains fed appliances.

The are all sorts of tanks for using the eaves and apex of roof spaces
if
that is an issue.

Thanks. I'll look around.

Andy Hall wrote:

On Wed, 6 Oct 2004 12:36:40 +0100, "John Aston"
wrote:


Hi, Andy.

Unfortunately, I have already replaced the service pipe with a new 32mm
diameter pipe. Cambridge Water tell me that they can't do anything about the
flow/pressure "because the supply is fed directly from a reservoir".


This rather suggests that their main is limited.

You cannot be seriosu.

Any main that feeds more than a couple of houses will be large enough to
feed one at high volume.

I think I am at about 3 bar hgere and water simply gushes out.

My main restriction is internal pipework and the water softener.


The best thing that you can do is to look at all the components after
the service pipe. e.g. stop cock full bore lever ball valve, 22mm
pipe internally to key points or 28mm for anything of any length,
avoid too many bends.


Totally agree here.

"John Aston" wrote in message
.. .
My own test was very empirical - I switched off all water supplied to
the
house and turned on the garden hose. The jet of water did not "feel"
very
substantial, particularly if is to be shared among appliances.

My outdoor tap delivers water at less than half the rate that I can get
at another tap internally. I have no idea why this is since I didn;t fit
the tap and I really don't need lots of water delivered quickly in the
garden.

However, you might find that your outdoor tap is similarly slow compared
to your internal, and you might be in better shape than you think.

Neil

On Wed, 6 Oct 2004 00:40:02 +0100, "John Aston"
wrote:

Many thanks to Andy Hall and others for their help earlier this year on the
design of my new plumbing system (http://tinyurl.com/3pwck etc.).
Unfortunately, thanks to a few months illness, I'm still at it - with a few
issues to resolve.

A question regarding an unvented domestic hot water system: Cambridge Water
tested my incoming main supply and informed me that the pressure = 2.8 bar
and the flow rate = 25 litres per minute. Is this sufficiently high for an
unvented supply feeding a family home containing two power showers, a bath,
five sinks, three toilets, a washing machine and a dishwasher?

Hi,

Before going for an expensive solution it may be worth checking that
they don't mean 25lpm _at_ 2.8 bar.

Also a garden tap is quite restrictive, a better measure would be to
open all direct mains taps at a time when the mains water pressure is
likely to be lowest.

[For information, the hot water will be heated indirectly in a 250 litre
tank by a condensing boiler. The mains supply pressure will be reduced (to 2
bar?) by a water softener, although a "high flow" softener, such as the
Kinetico 2020c HF, will be fitted to minimise this problem.]

Presumably the central heating could operate as a sealed system, even if the
hot water tank is vented?

One way round could be to use the hot tank as a heat bank with a
tanked supply for the bath and direct mains for the showers, both
heated via separate plate exchangers.

cheers,
Pete.

"Pete C" wrote in message
...
On Wed, 6 Oct 2004 00:40:02 +0100, "John Aston"
wrote:

Many thanks to Andy Hall and others for their help earlier this year on
the
design of my new plumbing system (http://tinyurl.com/3pwck etc.).
Unfortunately, thanks to a few months illness, I'm still at it - with a
few
issues to resolve.

A question regarding an unvented domestic hot water system: Cambridge
Water
tested my incoming main supply and informed me that the pressure = 2.8
bar
and the flow rate = 25 litres per minute. Is this sufficiently high for
an
unvented supply feeding a family home containing two power showers, a
bath,
five sinks, three toilets, a washing machine and a dishwasher?

Hi,

Before going for an expensive solution it may be worth checking that
they don't mean 25lpm _at_ 2.8 bar.

Also a garden tap is quite restrictive, a better measure would be to
open all direct mains taps at a time when the mains water pressure is
likely to be lowest.

[For information, the hot water will be heated indirectly in a 250 litre
tank by a condensing boiler. The mains supply pressure will be reduced
(to 2
bar?) by a water softener, although a "high flow" softener, such as the
Kinetico 2020c HF, will be fitted to minimise this problem.]

Presumably the central heating could operate as a sealed system, even if
the
hot water tank is vented?

One way round could be to use the hot tank as a heat bank with a
tanked supply for the bath and direct mains for the showers, both
heated via separate plate exchangers.

The initial problem is that he "thinks" his mains water supply can't handle
demand. A "full" mains pressure system appears out of the question. He
needs to assess the proper flowrate and pressure of his supply. He may be
OK.

If the mains is fine then a heat bank would be fine. One plate should be
fine with one bath and 2 showers.

If the mains is not that good then an element of stored water is required.
He could use a cold tank/cylinder setup heated to 70-80C with the draw-off
blended down, via a blending valve, to 50-55C. A bronze pump could pump
water out of the cylinder into a plate heat exchanger which will provide
mains fed showers.

I did that for a neighbour, who wanted a power shower. It was about the same
price to buy the plate and pump, etc, at the time.

In this case, if the mains can't cope, I would most likely go for a:

- combination cylinder for all low pressure hot water
- high flow combi for mains showers.

Divide and rule. A combination cylinder is about the same size as an
unvented cylinder but on low pressure, so no BBA approved fitter or large
overflows, pressure safety devices, etc.

"Neil Jones" wrote in message
...

"John Aston" wrote in message
.. .
My own test was very empirical - I switched off all water supplied to
the house and turned on the garden hose. The jet of water did not "feel"
"feel" very substantial, particularly if is to be shared among
appliances.


My outdoor tap delivers water at less than half the rate that I can get
at another tap internally. I have no idea why this is since I didn;t fit
the tap and I really don't need lots of water delivered quickly in the
garden.

However, you might find that your outdoor tap is similarly slow compared
to your internal, and you might be in better shape than you think.

Neil


Well, the garden tap does have its own stopcock and a double check valve in
line, so you could be right.

I'll do a test to see how long it takes to fill a large bucket from the main
supply stopcock where water comes in to the house...

"The Natural Philosopher" wrote in message
...
snip
I think I am at about 3 bar hgere and water simply gushes out.
My main restriction is internal pipework and the water softener.


Just out of interest, is your water softener a high flow type? Does it feed
a vented or unvented hot water system?

"John Aston" wrote in message
...
"Neil Jones" wrote in message
...

"John Aston" wrote in message
.. .

My own test was very empirical - I switched off all water supplied to
the house and turned on the garden hose. The jet of water did not
"feel"
"feel" very substantial, particularly if is to be shared among
appliances.

My outdoor tap delivers water at less than half the rate that I can get
at another tap internally. I have no idea why this is since I didn;t fit
the tap and I really don't need lots of water delivered quickly in the
garden.

However, you might find that your outdoor tap is similarly slow compared
to your internal, and you might be in better shape than you think.

Neil

Well, the garden tap does have its own stopcock and a double check valve
in
line, so you could be right.

I'll do a test to see how long it takes to fill a large bucket from the
main
supply stopcock where water comes in to the house...

Then if it has a conventional stop cock replace it with a 1/4 turn full bore
one (get a good quality one). And then see if the flow increase. I have
found a 25% improvement in flow in some cases when replacing old stop cocks.
In borderline cases, like yours it is essential to fit these. Also any cold
feed should be large bore and bends used.

On Thu, 07 Oct 2004 08:50:55 +0100, The Natural Philosopher
wrote:

Andy Hall wrote:

On Wed, 6 Oct 2004 12:36:40 +0100, "John Aston"
wrote:


Hi, Andy.

Unfortunately, I have already replaced the service pipe with a new 32mm
diameter pipe. Cambridge Water tell me that they can't do anything about the
flow/pressure "because the supply is fed directly from a reservoir".


This rather suggests that their main is limited.

You cannot be seriosu.

Any main that feeds more than a couple of houses will be large enough to
feed one at high volume.

I was really referring to the statement from the supplier.

If the flow is being measured at the end of the 32mm service pipe, the
pressure was 2.8 bar and the flow only 25lpm, it suggests that
something else is wrong.



I think I am at about 3 bar hgere and water simply gushes out.

My main restriction is internal pipework and the water softener.


The best thing that you can do is to look at all the components after
the service pipe. e.g. stop cock full bore lever ball valve, 22mm
pipe internally to key points or 28mm for anything of any length,
avoid too many bends.


Totally agree here.

..andy

To email, substitute .nospam with .gl

Neil Jones wrote:

"John Aston" wrote in message
.. .

My own test was very empirical - I switched off all water supplied to

the

house and turned on the garden hose. The jet of water did not "feel"

very

substantial, particularly if is to be shared among appliances.


My outdoor tap delivers water at less than half the rate that I can get
at another tap internally. I have no idea why this is since I didn;t fit
the tap and I really don't need lots of water delivered quickly in the
garden.

However, you might find that your outdoor tap is similarly slow compared
to your internal, and you might be in better shape than you think.

Non return valves? They slow it down a lot.

Neil

"The Natural Philosopher" wrote in message
...
Neil Jones wrote:

"John Aston" wrote in message
.. .

My own test was very empirical - I switched off all water supplied to

the

house and turned on the garden hose. The jet of water did not "feel"

very

substantial, particularly if is to be shared among appliances.


My outdoor tap delivers water at less than half the rate that I can get
at another tap internally. I have no idea why this is since I didn;t fit
the tap and I really don't need lots of water delivered quickly in the
garden.

However, you might find that your outdoor tap is similarly slow compared
to your internal, and you might be in better shape than you think.

Non return valves? They slow it down a lot.

It is compulsory to have one on an outside tap.

John Aston wrote:

"The Natural Philosopher" wrote in message
...
snip

I think I am at about 3 bar hgere and water simply gushes out.
My main restriction is internal pipework and the water softener.



Just out of interest, is your water softener a high flow type? Does it feed
a vented or unvented hot water system?


High flow ish. Its on 22mm copper feeds. System is unvented.

One shower at a time and its totally fabulous. Skin ripped off back etc.
Two showers together is only as good as yer typical large combi.

Pipework is mixture of 22mm and 15mm.

IMM wrote:

"The Natural Philosopher" wrote in message
...

Neil Jones wrote:


"John Aston" wrote in message
t...


My own test was very empirical - I switched off all water supplied to

the


house and turned on the garden hose. The jet of water did not "feel"

very


substantial, particularly if is to be shared among appliances.


My outdoor tap delivers water at less than half the rate that I can get
at another tap internally. I have no idea why this is since I didn;t fit
the tap and I really don't need lots of water delivered quickly in the
garden.

However, you might find that your outdoor tap is similarly slow compared
to your internal, and you might be in better shape than you think.


Non return valves? They slow it down a lot.


It is compulsory to have one on an outside tap.


True, but utterly irrelevant.

"John Aston" wrote in message
...

I'll do a test to see how long it takes to fill a large bucket from the
main
supply stopcock where water comes in to the house...



I did the test at 8.30 this morning.

My main stopcock in the house is a 32mm bore quarter-turn valve*. I couldn't
take the water directly from the stopcock outlet. It had to first go through
a straight 2m run of 15mm pipe before I could discharge it into a bucket.
(*Note: There is also a 25mm quarter-turn stopcock at the water meter end of
the supply pipe.)

I comfortably filled two 15 litre buckets in one minute.

"John Aston" wrote in message
...

"John Aston" wrote in message
...

I'll do a test to see how long it takes to fill
a large bucket from the main
supply stopcock where water comes in to
the house...

I did the test at 8.30 this morning.

My main stopcock in the house is a 32mm bore quarter-turn valve*. I
couldn't
take the water directly from the stopcock outlet. It had to first go
through
a straight 2m run of 15mm pipe before I could discharge it into a bucket.
(*Note: There is also a 25mm quarter-turn stopcock at the water meter end
of
the supply pipe.)

I comfortably filled two 15 litre buckets in one minute.

Your problems appear over. 30 litres/min is good enough. This should be
fine for 2 showers and one bath on a mains pressure system. Go for:

1. A heat bank

2. More cost effective:

View two combi boilers. One doing one zone of space heating (upstairs) the
other doing another (downstairs). Each boiler will have a programmer/stat
for each zone, preferably a Honeywell CM67, or equiv. Combine the DHW
outlets just before the bath using non-return valves and a small shock
arrestor expansion vessel, as per Worcester-Bosch Tech dept. It will fill a
bath pronto and give good power showers for two showers.

With combi's the most important figure is the flowrate. 11 litres/min is
fine for showes and the odd slow filling bath. Here is a recent post of
mine...


For an even better flow rate and cheap too for what you get, assess using
two Worcester-Bosch Junior combi's.

For high flowrates it is cost effective to use two Juniors and combine the
DHW outlets. Worcester-Bosch will supply a drawing on how to do it, or ask
me here. Two Juniors are available for around £1000 to £1100 depending on
what sized units you buy. They have 24 and 28 kW models, you could one 24kW
and one 28 kW. That is cheaper than the Worcester HighFlow 18 litres/min
floor mounted combi and can deliver about 21.5 litres/min @ 35 degree temp
rise and never run out of hot water. The highest flowrates of any
infinitely continuous combi is 22 litres/min @ 30 litre/min temp rise, which
is the ECO-Hometec which costs near £2K.

Have one combi do the downstairs heating on its own programmer/timer
(Honeywell CM67 or equiv) and one do upstairs. No complex and space
consuming zone valves used. Natural zoning, so you don't have to heat
upstairs when you are not up there saving fuel. The running cost will be
approx the same as a condensing boiler heating the whole house. No external
zone valves either, and simple wiring up too. The Juniors are simple and
don't even have internal 3-way valves.

If having two showers, have the shower split between the combi's to reduce
influence from one to the other.

Also if one goes down you will have another combi to give some heat in the
house and DHW too. Combine the outlets for the DHW bath pipes and all the
baths you want very quickly and no waiting. Best have the showers on
separate combi's.

Do not exceed the gas meter flowrate of 212 cu foot per hour. To calulate,
e.g., a boiler is 100,000 BTU/hr "input". Divide by 1000 giving 100 cu foot
per hour. Add up all the appliances.

The Juniors are not condensing combi's, yet overall heating costs will be
equivalent to one condensing boiler as the upstairs will not be heated most
of the time.

A win, win, situation.

Its advantages a

- cheap to install.
- quick to install.
- space saving (releases an airing cupboard). Both can go in the loft, or
at the back of the existing airing cupboard.
- never without heat in the house as two boioers are used.
- high flowrates (will do two showers and fill a bath in few minutes),
- No waiting for a cylinder to re-heat
- Natural zoning, one does upstairs and one does down
- hardly any electrical control work (running a wire to a programmers/stat
and power to each,
- simple no brainer installation,
- minimal components used.
- less piping used
- cheap to run overall as upstairs would be off most of the time
- etc.

On Fri, 8 Oct 2004 10:27:16 +0100, "John Aston"
wrote:


"John Aston" wrote in message
...

I'll do a test to see how long it takes to fill a large bucket from the
main
supply stopcock where water comes in to the house...



I did the test at 8.30 this morning.

My main stopcock in the house is a 32mm bore quarter-turn valve*. I couldn't
take the water directly from the stopcock outlet. It had to first go through
a straight 2m run of 15mm pipe before I could discharge it into a bucket.
(*Note: There is also a 25mm quarter-turn stopcock at the water meter end of
the supply pipe.)

I comfortably filled two 15 litre buckets in one minute.


OK. That changes the picture completely. You can go for the
planned pressurised storage system and get very good results.

Two things.

Make sure that you go for a large enough HW cylinder - I would suggest
a 150litre one or more. I have a 200 litre HW cylinder for
similar requirements to yours and it does the job admirably, even in
coldest weather.

The other thing is to plan the internal pipe sizes carefully.

If the water softener is a long way from the stop tap then perhaps a
28mm pipe to it, but certainly 22mm.

For the run from there to the HW cylinder, 22mm.

If there is a run for cold water to several bathroom taps make that
22mm as well.

You can then drop down to smaller sizes closer to the taps or fit flow
restrictors.

The trick becomes to size and arrange things to provide reasonable
flow balancing.




..andy

To email, substitute .nospam with .gl

John Aston wrote:

I comfortably filled two 15 litre buckets in one minute.

Check the flow rate again at 6.30pm on a weekday. IME a 2:1 variation
can be experienced.

Regards
Capitol

Andy Hall wrote:

On Fri, 8 Oct 2004 10:27:16 +0100, "John Aston"
wrote:


"John Aston" wrote in message
...

I'll do a test to see how long it takes to fill a large bucket from the

main

supply stopcock where water comes in to the house...



I did the test at 8.30 this morning.

My main stopcock in the house is a 32mm bore quarter-turn valve*. I couldn't
take the water directly from the stopcock outlet. It had to first go through
a straight 2m run of 15mm pipe before I could discharge it into a bucket.
(*Note: There is also a 25mm quarter-turn stopcock at the water meter end of
the supply pipe.)

I comfortably filled two 15 litre buckets in one minute.



OK. That changes the picture completely. You can go for the
planned pressurised storage system and get very good results.

Two things.

Make sure that you go for a large enough HW cylinder - I would suggest
a 150litre one or more. I have a 200 litre HW cylinder for
similar requirements to yours and it does the job admirably, even in
coldest weather.

The other thing is to plan the internal pipe sizes carefully.

If the water softener is a long way from the stop tap then perhaps a
28mm pipe to it, but certainly 22mm.

For the run from there to the HW cylinder, 22mm.

If there is a run for cold water to several bathroom taps make that
22mm as well.

You can then drop down to smaller sizes closer to the taps or fit flow
restrictors.

The trick becomes to size and arrange things to provide reasonable
flow balancing.




I second this advice in every detail. Essentially its what I have, and
it works well.



.andy

To email, substitute .nospam with .gl

On Thu, 07 Oct 2004 01:23:30 +0100, John Aston wrote:


Ed Sirett wrote in message
news
On Wed, 06 Oct 2004 00:40:02 +0100, John Aston wrote:

snip

A question regarding an unvented domestic hot water system: Cambridge
Water
tested my incoming main supply and informed me that the pressure = 2.8
bar
and the flow rate = 25 litres per minute. Is this sufficiently high for
an
unvented supply feeding a family home containing two power showers, a
bath,
five sinks, three toilets, a washing machine and a dishwasher?

snip

Given that you want to soften the water I strongly think that a pumped
storage cistern approach will be best.

Better than an accumulator?


The problem is that a water softener is a _huge_ restriction on the flow and
with any form of direct HW systems it will be the bottle neck.


I'm really surprised that 2.8 bar
static on 32mm (25mm inside) MDPE pipe gives only 25lpm.
This implies that the supply in the road is somewhat restrictive.

I wonder if the water meter could be resticting the flow significantly.

It does not make a problem elsewhere.


--
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 Thu, 07 Oct 2004 01:23:30 +0100, John Aston wrote:


Ed Sirett wrote in message
news
On Wed, 06 Oct 2004 00:40:02 +0100, John Aston wrote:

snip

A question regarding an unvented domestic hot water system: Cambridge
Water
tested my incoming main supply and informed me that the pressure =
2.8
bar
and the flow rate = 25 litres per minute. Is this sufficiently high
for
an
unvented supply feeding a family home containing two power showers, a
bath,
five sinks, three toilets, a washing machine and a dishwasher?

snip

Given that you want to soften the water I strongly think that a pumped
storage cistern approach will be best.

Better than an accumulator?


The problem is that a water softener is a _huge_ restriction on the flow
and
with any form of direct HW systems it will be the bottle neck.

Best have a phosphor in-line descaler.

I'm really surprised that 2.8 bar
static on 32mm (25mm inside) MDPE pipe gives only 25lpm.
This implies that the supply in the road is somewhat restrictive.

I wonder if the water meter could be resticting the flow significantly.

It does not make a problem elsewhere.


--
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
snip

The problem is that a water softener is a _huge_ restriction on the flow
and
with any form of direct HW systems it will be the bottle neck.

snip

Is this your personal experience?

The Kinetico 2020c High Flow Softener has a service flow rate of 33 lpm and
a peak flow rate of 51 lpm. Providing that I use a suitably large pipe
diameter, is this really going to appreciably slow down my 30 lpm supply?

On Sat, 9 Oct 2004 23:40:52 +0100, "John Aston"
wrote:


Ed Sirett wrote in message
news
snip

The problem is that a water softener is a _huge_ restriction on the flow
and
with any form of direct HW systems it will be the bottle neck.

snip

Is this your personal experience?

The Kinetico 2020c High Flow Softener has a service flow rate of 33 lpm and
a peak flow rate of 51 lpm. Providing that I use a suitably large pipe
diameter, is this really going to appreciably slow down my 30 lpm supply?


There are some things that you can do to mitigate this:

- Look for the highest flow model that makes sense. This does not
necessarily mean picking one that is suitable for a larger number of
people in the house - that is more of an issue with single chamber
machines which regenerate at night, and those for more people simply
have a larger resin chamber to be able to deliver a greater volume of
water over a day.
You can get commercial models with higher flow, but they get rapidly
expensive.. If you look at specs. you can ask the suppliers for
their flow/pressure graphs (for the system, not just the valve) and
pick from these. Some machines have 1" rather than 3/4" fittings
which can help.

- You can get wide bore hoses. Often, the ones normally supplied
have as little as 12mm bore, so it's useful to get larger ones. I
replaced mine on a Kinetico a while ago and it did help somewhat.

- The stop valves supplied with the machines are sometimes not full
bore. You can use 22mm or as discussed before, 28mm quarter turn
lever ball valves.

- You have to have a double check valve with a water softener, and
these do tend to restrict flow. You can fit a larger one than that
implied by the pipe - e.g. a 28mm one on a 22mm pipe.


..andy

To email, substitute .nospam with .gl

On Sat, 09 Oct 2004 23:40:52 +0100, John Aston wrote:


Ed Sirett wrote in message
news
snip

The problem is that a water softener is a _huge_ restriction on the flow
and
with any form of direct HW systems it will be the bottle neck.

snip

Is this your personal experience?

The Kinetico 2020c High Flow Softener has a service flow rate of 33 lpm and
a peak flow rate of 51 lpm. Providing that I use a suitably large pipe
diameter, is this really going to appreciably slow down my 30 lpm
supply?

Yes this is my diret experience at one site.
It would clearly not have been had they used the Kinetico High Flow unit
which I expect is a tad more pricy than a typical unit.


--
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

On Sat, 09 Oct 2004 23:02:00 +0100, IMM wrote:


"Ed Sirett" wrote in message
news
On Thu, 07 Oct 2004 01:23:30 +0100, John Aston wrote:


Ed Sirett wrote in message
news On Wed, 06 Oct 2004 00:40:02 +0100, John Aston wrote:

snip

A question regarding an unvented domestic hot water system: Cambridge
Water
tested my incoming main supply and informed me that the pressure =
2.8
bar
and the flow rate = 25 litres per minute. Is this sufficiently high
for
an
unvented supply feeding a family home containing two power showers, a
bath,
five sinks, three toilets, a washing machine and a dishwasher?

snip

Given that you want to soften the water I strongly think that a pumped
storage cistern approach will be best.

Better than an accumulator?


The problem is that a water softener is a _huge_ restriction on the flow
and
with any form of direct HW systems it will be the bottle neck.

Best have a phosphor in-line descaler.

As to whether this is best or not will depend on the reason the OP wishes
to threat the water.
Adding phosphates is not the same as exchanging ions and that's not the same
as removing ions.


--
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
The problem is that a water softener is a _huge_ restriction on the
flow
and
with any form of direct HW systems it will be the bottle neck.

Best have a phosphor in-line descaler.

As to whether this is best or not will depend on the reason the OP wishes
to threat the water.
Adding phosphates is not the same as exchanging ions and that's not the
same
as removing ions.

This is a borderline mains pressure system. Anything that may restrict
flow/pressure should be avoided. Most people only want to descale. A
phosphor canister does that well and does not restrict flow.

Ed Sirett wrote:

On Thu, 07 Oct 2004 01:23:30 +0100, John Aston wrote:


Ed Sirett wrote in message
news
On Wed, 06 Oct 2004 00:40:02 +0100, John Aston wrote:


snip

A question regarding an unvented domestic hot water system: Cambridge

Water

tested my incoming main supply and informed me that the pressure = 2.8

bar

and the flow rate = 25 litres per minute. Is this sufficiently high for

an

unvented supply feeding a family home containing two power showers, a

bath,

five sinks, three toilets, a washing machine and a dishwasher?

snip

Given that you want to soften the water I strongly think that a pumped
storage cistern approach will be best.

Better than an accumulator?



The problem is that a water softener is a _huge_ restriction on the flow and
with any form of direct HW systems it will be the bottle neck.


No. just *A* bottle neck.

Mine is totally capable if one shower at insane flows, and two showers
at normal flows.



I'm really surprised that 2.8 bar
static on 32mm (25mm inside) MDPE pipe gives only 25lpm.
This implies that the supply in the road is somewhat restrictive.

I wonder if the water meter could be resticting the flow significantly.


It does not make a problem elsewhere.

IMM wrote:

"Ed Sirett" wrote in message
news

The problem is that a water softener is a _huge_ restriction on the

flow

and

with any form of direct HW systems it will be the bottle neck.

Best have a phosphor in-line descaler.


As to whether this is best or not will depend on the reason the OP wishes
to threat the water.
Adding phosphates is not the same as exchanging ions and that's not the

same

as removing ions.


This is a borderline mains pressure system. Anything that may restrict
flow/pressure should be avoided. Most people only want to descale.

That is simply not true.

Most people want to eliminate nasty scums from their baths, and scale
deposits as well.

A
phosphor canister does that well and does not restrict flow.