What is head when talking about water systems in a house?
How does it relate to hot/cold water and water for radiators?
Thanks in advance,

CM.

"Charles Middleton" wrote in message
oups.com...

What is head when talking about water systems in a house?
How does it relate to hot/cold water and water for radiators?
Thanks in advance,

Simply head equals pressure. In a house with tank in the loft the presure
is "x" head. The head refferes to the height of the tank from its water
line. The higher the more the pressure. 1 bar is approx 30 foot. If the
tank is 30 foot above you the pressure where you are will be 1 bar. That is
why in 3 story house when the tank is in the loft, on the 4 th floor, the
pressure in the basement is high and on the top floor very low.

A man I know, to increse the pressure on his shower installed another large
100 gallon water tank in the loft. He was confued at why the pressure had
stayed the same.

So if you have a 4 floor house and the pump and boiler in the basement the
pump may not reach the top floor radiators. The more bends and elbows in a
pipe, the more the pressure is reduced, so a punmp has to be sized with the
pipe run taken into acciount. Lots of elbows and the 20 foot head pump may
only raise water 15 foot.

A pump may be rated at 20 foot head. If a 40 foot clear plastic tube is
attached to the outlet of the pump and it runs up directly vertical, if the
pump pumps water from the same level the pump is on, the water should rise
up 20 foot in the plastic tube.

You must have heard the term "a head (pressure) of steam" on films, when the
train driver or ships engineer waits for the steam pressure to build up to
move the ship or train. Or the fireman shovels coal in like hell to keep
"the head up" to keep up the speed.

In an earlier contribution to this discussion,
Charles Middleton wrote:

What is head when talking about water systems in a house?
How does it relate to hot/cold water and water for radiators?
Thanks in advance,

CM.

It's a measure of static pressure expressed in terms of the pressure which
will exist at the bottom of a vertical column of water of specified height.
For example, the head of water at your kitchen tap (for a stored hot water
system) may be about 15 feet (roughly 0.5 bar in pressure terms) - being the
vertical distance of the surface level of the water in the header tank above
the tap.

The static head of water in your central heating system is measured in the
same way (assuming a vented system with a small F&E tank in the attic). The
static head in the downstairs rads will be greater than that in the upstairs
rads due to their relative vertical positions. In a pumped central heating
system there will, of course, be a dynamic pressure which is exerted by the
pump and superimposed on the static pressures.

Hope this makes sense!
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

In an earlier contribution to this discussion,
IMM wrote:


So if you have a 4 floor house and the pump and boiler in the
basement the pump may not reach the top floor radiators.

That might be true if the pump was picking up its water from an
open-to-atmosphere trough in the basement. But, of course, it isn't! It's
being fed with a static head of water commensurate with the 4-floor house -
and only has to generate sufficient *dynamic* pressure to overcome the flow
losses.

Back to your Physics text book, Mr IMM - if you ever had one!
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

In article ,
IMM wrote:
So if you have a 4 floor house and the pump and boiler in the basement
the pump may not reach the top floor radiators. The more bends and
elbows in a pipe, the more the pressure is reduced, so a punmp has to be
sized with the pipe run taken into acciount. Lots of elbows and the 20
foot head pump may only raise water 15 foot.

The *pressure* is reduced by bends and elbows, is it?

Remind me again of what you claim to earn a living at?

--
*'Progress' and 'Change' are not synonyms.

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

"Charles Middleton" wrote in message
oups.com...
What is head when talking about water systems in a house?
How does it relate to hot/cold water and water for radiators?
Thanks in advance,

CM.


The term Head, when used in plumbing, is the height you have from a static
feed tank which is above all other appliances. So, the higher the head of
water, the more pressure you get in the pipes to move the water below it.


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.792 / Virus Database: 536 - Release Date: 09/11/04

In article ,
"IMM" writes:

So if you have a 4 floor house and the pump and boiler in the basement the
pump may not reach the top floor radiators. The more bends and elbows in a
pipe, the more the pressure is reduced, so a punmp has to be sized with the
pipe run taken into acciount. Lots of elbows and the 20 foot head pump may
only raise water 15 foot.

Hum, you have got a couple of different concepts mixed up here.

A pump may be rated at 20 foot head. If a 40 foot clear plastic tube is
attached to the outlet of the pump and it runs up directly vertical, if the
pump pumps water from the same level the pump is on, the water should rise
up 20 foot in the plastic tube.

Yes, but the central heating pump is responsible for circulating
the water in the system, not keeping the upstairs radiators filled
up. Central heating pump only has to overcome the dynamic pressure
drop of the system at the operating flow rate which is normally of
the order of a few feet of head, and is not related to the hight
of the header tank or the fill pressure of a sealed system. A
central heating pump won't normally generate anything like the
head required to pump water from the ground floor to a loft
header tank or even upstairs radiators, and doesn't need to.

--
Andrew Gabriel

In article ,
Andrew Gabriel wrote:
A
central heating pump won't normally generate anything like the
head required to pump water from the ground floor to a loft
header tank or even upstairs radiators, and doesn't need to.

I'm trying to remember my basic physics about the maximum head an impeller
pump can generate? I'd think it unlikely to be more than 1 bar?

--
*Two many clicks spoil the browse *

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

In article ,
"Dave Plowman (News)" writes:
In article ,
Andrew Gabriel wrote:
A
central heating pump won't normally generate anything like the
head required to pump water from the ground floor to a loft
header tank or even upstairs radiators, and doesn't need to.

I'm trying to remember my basic physics about the maximum head an impeller
pump can generate? I'd think it unlikely to be more than 1 bar?

I can't think of a reason for a limit. It basically uses
centrifugal force at the outer edge of a volume of spinning
water, and if you make the diameter larger or the angular
velocity higher, the pressure should increase. Maybe there's
some factor I'm overlooking (cavitation)? Of course, there's
a limit to what a 3" diameter impeller on a 100W motor in a
central heating pump can achieve. I just looked up the spec
of one typical heating pump, and it's 0.5m head.

--
Andrew Gabriel

"Set Square" wrote in message
...
In an earlier contribution to this discussion,
IMM wrote:


So if you have a 4 floor house and the pump and boiler in the
basement the pump may not reach the top floor radiators.

That might be true if the pump was picking up its water from an
open-to-atmosphere trough in the basement. But, of course, it isn't! It's
being fed with a static head of water commensurate with the 4-floor
house -
and only has to generate sufficient *dynamic* pressure to overcome the
flow
losses.

Back to your Physics text book, Mr IMM - if you ever had one!

You need to know more about heating and the many plumbers who have had to
replace a pump with a more powerful version because the tops rads only get
warm, or not at all

"Dave Plowman (News)" wrote in message
...
In article ,
IMM wrote:
So if you have a 4 floor house and the pump and boiler in the basement
the pump may not reach the top floor radiators. The more bends and
elbows in a pipe, the more the pressure is reduced, so a punmp has to be
sized with the pipe run taken into acciount. Lots of elbows and the 20
foot head pump may only raise water 15 foot.

The *pressure* is reduced by bends and elbows, is it?

What the f**k do you know about heating? err, err, er...nothing.

Remind me again of what you claim to earn a living at?

Not twiddling a knob.

On Thu, 11 Nov 2004 18:51:52 +0000, Set Square wrote:

In an earlier contribution to this discussion,
IMM wrote:


So if you have a 4 floor house and the pump and boiler in the
basement the pump may not reach the top floor radiators.

That might be true if the pump was picking up its water from an
open-to-atmosphere trough in the basement. But, of course, it isn't! It's
being fed with a static head of water commensurate with the 4-floor house -
and only has to generate sufficient *dynamic* pressure to overcome the flow
losses.

Back to your Physics text book, Mr IMM - if you ever had one!

Thanks. Whilst he started well when talking about the roof tanks, the plot
got lost on CH circulators.

IMM has some agreement with higher powers than I deal with that exempt him
from the known laws nature.



--
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

"Andrew Gabriel" wrote in message
...
In article ,
"IMM" writes:

So if you have a 4 floor house and the pump and boiler in the basement
the
pump may not reach the top floor radiators. The more bends and elbows
in a
pipe, the more the pressure is reduced, so a punmp has to be sized with
the
pipe run taken into acciount. Lots of elbows and the 20 foot head pump
may
only raise water 15 foot.

Hum, you have got a couple of different concepts mixed up here.

A pump may be rated at 20 foot head. If a 40 foot clear plastic tube is
attached to the outlet of the pump and it runs up directly vertical, if
the
pump pumps water from the same level the pump is on, the water should
rise
up 20 foot in the plastic tube.

Yes, but the central heating pump is responsible for circulating
the water in the system, not keeping the upstairs radiators filled
up. Central heating pump only has to overcome the dynamic pressure
drop of the system at the operating flow rate which is normally of
the order of a few feet of head, and is not related to the hight
of the header tank or the fill pressure of a sealed system. A
central heating pump won't normally generate anything like the
head required to pump water from the ground floor to a loft
header tank or even upstairs radiators, and doesn't need to.

Depends. A pump will have "x" head on it inlet and oulet, in theory
balanaced out. In practice the the boiler gets in the way and a lot of
piping. From what you say a pump need only just move a water a little. If
the restriction is high on the inlet, the suction side you may find there
will be little flow, if any, at the far end.

In article ,
IMM wrote:
You need to know more about heating and the many plumbers who have had
to replace a pump with a more powerful version because the tops rads
only get warm, or not at all

Likely because they're the furthest from the pump and the longer the
pipework, the greater the resistance to the flow.

--
*If you don't like the news, go out and make some.

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

In article ,
IMM wrote:
The *pressure* is reduced by bends and elbows, is it?

What the f**k do you know about heating? err, err, er...nothing.

Obviously rather more than you, though, then?

Remind me again of what you claim to earn a living at?

Not twiddling a knob.

You'd not last five minutes at it. It's something that requires skill. Not
just quoting reams from websites and brochures without understanding a
word of it.

--
*What do little birdies see when they get knocked unconscious? *

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

In an earlier contribution to this discussion,
IMM wrote:


Depends. A pump will have "x" head on it inlet and oulet, in theory
balanaced out. In practice the the boiler gets in the way and a lot of
piping. From what you say a pump need only just move a water a
little. If the restriction is high on the inlet, the suction side
you may find there will be little flow, if any, at the far end.

The important point - which you need to get into *your* head - is that this
has nothing to do with *static* head (which is self-cancelling in a
circulating system) - but is simply a function of circuit resistance.

If you took all the pipework in your notional 4-storey house, and laid it
out in one *horizontal* plane, you would have exactly the same relationship
between pump dynamic pressure and cricuit flow as you had with the original
vertical pipework.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

"Set Square" wrote in message
...
In an earlier contribution to this discussion,
IMM wrote:


Depends. A pump will have "x" head on it inlet and oulet, in theory
balanaced out. In practice the the boiler gets in the way and a lot of
piping. From what you say a pump need only just move a water a
little. If the restriction is high on the inlet, the suction side
you may find there will be little flow, if any, at the far end.

The important point - which you need to get into *your* head - is that
this
has nothing to do with *static* head (which is self-cancelling in a
circulating system) - but is simply a function of circuit resistance.

The pump head overcomes that. Duh!

"Dave Plowman (News)" wrote in message
...
In article ,
IMM wrote:
The *pressure* is reduced by bends and elbows, is it?

What the f**k do you know about heating? err, err, er...nothing.

Obviously rather more than you, though, then?

That is a question. Answer NO.

Stop commenting on fields you know sweet FA about.

Keep twiddling the knob.

"Dave Plowman (News)" wrote in message
...
In article ,
IMM wrote:
You need to know more about heating and the many plumbers who have had
to replace a pump with a more powerful version because the tops rads
only get warm, or not at all

Likely because they're the furthest from the pump and the longer the
pipework, the greater the resistance to the flow.

Go way....you don't say! Duh!

In message , IMM writes

"Dave Plowman (News)" wrote in message
...
In article ,
IMM wrote:
The *pressure* is reduced by bends and elbows, is it?

What the f**k do you know about heating? err, err, er...nothing.

Obviously rather more than you, though, then?

That is a question. Answer NO.

Stop commenting on fields you know sweet FA about.

Keep twiddling the knob.

It's you who claims to be able to give head

.... but whose, we must ask?



--
geoff

Charles Middleton wrote:

What is head when talking about water systems in a house?
How does it relate to hot/cold water and water for radiators?
Thanks in advance,

CM.

Something to do with sucking off. ;-)

Andrew Gabriel wrote:

In article ,
"IMM" writes:

So if you have a 4 floor house and the pump and boiler in the basement the
pump may not reach the top floor radiators. The more bends and elbows in a
pipe, the more the pressure is reduced, so a punmp has to be sized with the
pipe run taken into acciount. Lots of elbows and the 20 foot head pump may
only raise water 15 foot.


Hum, you have got a couple of different concepts mixed up here.

Generally, with IMM, the term 'concept' is not applied.

His only advantage over a partially trained parrot, is that he is likely
to live less long, oh, and he doesn't *always* crap on the floor of his
cage. He's been known to hit the walls as well.....

IMM wrote:

You need to know more about heating and the many plumbers who have had to
replace a pump with a more powerful version because the tops rads only get
warm, or not at all


I am sure that so, but I find bleeding the air out of them is cheaper.

IMM wrote:



What the f**k do you know about heating? err, err, er...nothing.


Remind me again of what you claim to earn a living at?


Not twiddling a knob.


No, I expect you do that in your spare time.

Ed Sirett wrote:



Thanks. Whilst he started well when talking about the roof tanks, the plot
got lost on CH circulators.

IMM has some agreement with higher powers than I deal with that exempt him
from the known laws nature.


Its calle 'conviction plumbing'

Like when teh gibbon that installed by CH boler insisted teh HW tank go
'as high as possible' to get 'good pressure.

This wa on a mains pressure system boiler.

Come to think of it, might have BEEN IMM.
In which case mate, sorry about teh gambling problem and the wife
walking out on you, but don't nick my effing plumbing bits, or its the
fuzz net time OK?

Steve Firth wrote:

IMM wrote:


Stop commenting on fields you know sweet FA about.


You probably know a lot about giving head.

No. He's just a private knob twiddler.

Did you hear the one about the two whales and the fishing boat?

One whale bets the other he can't do a spout and wash the fishermen
off..so the other says. 'You're on', and pops one up right over the boat.

The other whales says 'go on then, eat the *******s'

'Not on mate' replies the first 'I was up for the blow job but I'm not
swallowing any seamen'

On Fri, 12 Nov 2004 01:13:42 +0000, (Steve Firth)
wrote:

IMM wrote:

Depends. A pump will have "x" head on it inlet and oulet, in theory
balanaced out. In practice the the boiler gets in the way and a lot of
piping. From what you say a pump need only just move a water a little. If
the restriction is high on the inlet, the suction side you may find there
will be little flow, if any, at the far end.

This drivel was brought to you by the man who criticises the spelling
and grammar of other newsgroup contributors.


It seems as though either Stanley Unwin or Yoda was his English
teacher.......



--

..andy

To email, substitute .nospam with .gl

"The Natural Philosopher" wrote in message
...
Steve Firth wrote:

IMM wrote:


Stop commenting on fields you know sweet FA about.

snip appalling jokes

"The Natural Philosopher" wrote in message
...
Andrew Gabriel wrote:

In article ,
"IMM" writes:

So if you have a 4 floor house and the pump and boiler in the basement
the
pump may not reach the top floor radiators. The more bends and elbows
in a
pipe, the more the pressure is reduced, so a punmp has to be sized with
the
pipe run taken into acciount. Lots of elbows and the 20 foot head pump
may
only raise water 15 foot.


Hum, you have got a couple of different concepts mixed up here.

Generally, with IMM, the term 'concept' is not applied.

snip tripe by a snot

I saw the prog on Lucan last night. What a crowd of snot *******. The
police could have gone around and got the ******* as he phoned a relative
when they were there. He said I'll see them tomorrow and disappeared. The
police thought a lord would actually turn up the next day and never went for
him. How the class system poisons the minds of people.

Shows how thick the snots are. Trying to bump off the wife that way. What a
silly snot tosser.

"The Natural Philosopher" wrote in message
...
IMM wrote:

You need to know more about heating and the many plumbers who have had
to
replace a pump with a more powerful version because the tops rads only
get
warm, or not at all


I am sure that so, but I find bleeding the air out of them is cheaper.

Of course.

"The Natural Philosopher" wrote in message
...
Ed Sirett wrote:



Thanks. Whilst he started well when talking about the roof tanks, the
plot
got lost on CH circulators.

IMM has some agreement with higher powers than I deal with that exempt
him
from the known laws nature.


Its calle 'conviction plumbing'

Like when teh gibbon that installed by CH boler insisted teh HW tank go
'as high as possible' to get 'good pressure.

What do you expect from the fens.

This wa on a mains pressure system boiler.

He had a tank on its as well. Boy are they out there.

Come to think of it, might have BEEN IMM.

Wouldn't be seen anywhere near the place. And doing work for a snot? Not
on your nelly.

In which case mate, sorry
about teh gambling problem

That is a snot passtime, as per Lucan.

and the wife walking out on you, but
don't nick my effing plumbing bits, or its the
fuzz net time OK?

You grab people by the fuzz?

"raden" wrote in message
...
In message , IMM writes

"Dave Plowman (News)" wrote in message
...
In article ,
IMM wrote:
The *pressure* is reduced by bends and elbows, is it?

What the f**k do you know about heating? err, err, er...nothing.

Obviously rather more than you, though, then?

That is a question. Answer NO.

Stop commenting on fields you know sweet FA about.

Keep twiddling the knob.

It's you who claims to be able to give head

Maxie, I am not claiming to give head.

... but whose, we must ask?

Maxie?

"Steve Firth" wrote in message
. ..
IMM wrote:

Depends. A pump will have "x" head on it inlet and oulet, in theory
balanaced out. In practice the the boiler gets in the way and a lot of
piping. From what you say a pump need only just move a water a little.
If
the restriction is high on the inlet, the suction side you may find
there
will be little flow, if any, at the far end.

snip drivel by a **** kicking bumpkin

"Steve Firth" wrote in message
...
Dave Plowman (News) wrote:

snip drivel by a **** kicking bumpkin and a lunatic

"Steve Firth" wrote in message
.. .
IMM wrote:

Stop commenting on fields you know sweet FA about.


snip drivel by a **** kicking bumpkin

"Andy Hall" wrote in message
...

It seems as though either Stanley Unwin or Yoda was his English
teacher.......

Who is Yoda?

How much did you give to the rich this week?

On Fri, 12 Nov 2004 09:26:27 -0000, "IMM" wrote:


"The Natural Philosopher" wrote in message
...
Andrew Gabriel wrote:

In article ,
"IMM" writes:

So if you have a 4 floor house and the pump and boiler in the basement
the
pump may not reach the top floor radiators. The more bends and elbows
in a
pipe, the more the pressure is reduced, so a punmp has to be sized with
the
pipe run taken into acciount. Lots of elbows and the 20 foot head pump
may
only raise water 15 foot.


Hum, you have got a couple of different concepts mixed up here.

Generally, with IMM, the term 'concept' is not applied.

snip tripe by a snot

I saw the prog on Lucan last night. What a crowd of snot *******. The
police could have gone around and got the ******* as he phoned a relative
when they were there. He said I'll see them tomorrow and disappeared. The
police thought a lord would actually turn up the next day and never went for
him. How the class system poisons the minds of people.

It seems to me that the only person around here with the poisoned mind
as far as class is concerned is your good self.





--

..andy

To email, substitute .nospam with .gl

"IMM" wrote in message
...


snip drivel by a **** kicking bumpkin and a lunatic



Deleting your own words now?

":::Jerry::::" wrote in message
...

"IMM" wrote in message
...


snip drivel by a **** kicking bumpkin and a lunatic

Deleting your own words now?

Another one.

"Andy Hall" wrote in message
...
On Fri, 12 Nov 2004 09:26:27 -0000, "IMM" wrote:


"The Natural Philosopher" wrote in message
...
Andrew Gabriel wrote:

In article ,
"IMM" writes:

So if you have a 4 floor house and the pump and boiler in the
basement
the
pump may not reach the top floor radiators. The more bends and
elbows
in a
pipe, the more the pressure is reduced, so a punmp has to be sized
with
the
pipe run taken into acciount. Lots of elbows and the 20 foot head
pump
may
only raise water 15 foot.


Hum, you have got a couple of different concepts mixed up here.

Generally, with IMM, the term 'concept' is not applied.

snip tripe by a snot

I saw the prog on Lucan last night. What a crowd of snot *******. The
police could have gone around and got the ******* as he phoned a relative
when they were there. He said I'll see them tomorrow and disappeared. The
police thought a lord would actually turn up the next day and never went
for
him. How the class system poisons the minds of people.

It seems to me that the only person around here with the poisoned mind
as far as class is concerned is your good self.

Study British society and the class structure permeates it. It is its
downfall.