Header tank above cylinder
 

Is it right that the higher the cold water storage tank is above a standard vented cylinder the better pressure is available out of the hot water taps???

Is there a minimum height the tank has to be above the cylinder?

"pauliepie" wrote
| Is it right that the higher the cold water storage tank
| is above a standard vented cylinder the better pressure
| is available out of the hot water taps???

No. It is the height of the tank above the *tap* that matters.

| Is there a minimum height the tank has to be above the cylinder?

No; some combination tanks have the cold tank immediately above the hot, in
the same assembly.

Owain

Also if the tap is a bath mixer with shower say 1.5m long hose,this will
reduce your head of pressure at outlet

For good pressure at shower head you need a minium of 1m from bottom of cold
tank to the shower head,and preferably balanced pipework.

So if you have a standard airing cupboard with a 36x18 cylinder and a 30 gal cold water storage tank above it and the shower head on the opposite wall in the bathroom mounted the same height as the tank...It is best to move the tank in the loft!!!!

What if there is no room to put a tank in the loft, there will be 1m above the taps but not above the shower head?

I guess its the same for a heating header tank, does this have to be a certain height above the top radiator/pipework.

Is there a rule to say that the htg hdr tank has to be higher than the cold water tank or vice versa?

Many thanks guys

"pauliepie" wrote in message
...

So if you have a standard airing cupboard with a 36x18 cylinder and a 30
gal cold water storage tank above it and the shower head on the opposite
wall in the bathroom mounted the same height as the tank...It is best to
move the tank in the loft!!!!

What if there is no room to put a tank in the loft, there will be 1m
above the taps but not above the shower head?

I guess its the same for a heating header tank, does this have to be a
certain height above the top radiator/pipework.

Is there a rule to say that the htg hdr tank has to be higher than the
cold water tank or vice versa?

Many thanks guys

Best remove the cylinder and tank and fit a thermal store. Then high
pressure hot water all around. Cheap enough from:
http://www.newarkcyl.freeserve.co.uk

Alos look at:
http://www.mcdonald-engineers.com
http://www.elsonho****er.co.uk/ (make square stirage vessels)
http://www.heatweb.com (make heat banks and storage vessels to size)
http://www.albion-online.co.uk (make thermal stores and stioarge vessels)
http://www.range-cylinders.co.uk (make cylindrical heat banks and storage
vessels. Will make to order)
http://www.gledhill.net (make heat banks and storage vessels)
http://www.newarkcyl.freeserve.co.uk (make cylindrical thermal stores and
storage vessels. (They are quite cheap and will make to order)
http://www.telford-group.com make cylindrical thermal stores and storage
vessels
http://www.chelmerheating.co.uk (make cylindrical thermal stores)
http://www.rcmgroup.co.uk/




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"Doctor Evil" wrote in message
...

"pauliepie" wrote in message
...

So if you have a standard airing cupboard with a 36x18 cylinder and a 30
gal cold water storage tank above it and the shower head on the opposite
wall in the bathroom mounted the same height as the tank...It is best to
move the tank in the loft!!!!

What if there is no room to put a tank in the loft, there will be 1m
above the taps but not above the shower head?

I guess its the same for a heating header tank, does this have to be a
certain height above the top radiator/pipework.

Is there a rule to say that the htg hdr tank has to be higher than the
cold water tank or vice versa?

Many thanks guys

Best remove the cylinder and tank and fit a thermal store. Then high
pressure hot water all around. Cheap enough from:
http://www.newarkcyl.freeserve.co.uk

Or just replace the cylinder with a shower coil cylinder. This is a normal
low pressure cylinder that has a dedicated shower only coil running though
it at the top. The cold mains runs into the coil and is instantly heated
giving a high pressure shower. You can fit a blending valve on the hot
water draw-off set to 50C and have the stored water at 60, 70, 80C or
whatever. A superior alternative to a power shower pump.

They are also available in combination cylinders with the cold water tank
and hot water cylinder combined, eliminating tanks in the loft.

Alsp look at:
http://www.mcdonald-engineers.com
http://www.elsonho****er.co.uk/ (make square stirage vessels)
http://www.heatweb.com (make heat banks and storage vessels to size)
http://www.albion-online.co.uk (make thermal stores and stioarge vessels)
http://www.range-cylinders.co.uk (make cylindrical heat banks and storage
vessels. Will make to order)
http://www.gledhill.net (make heat banks and storage vessels)
http://www.newarkcyl.freeserve.co.uk (make cylindrical thermal stores and
storage vessels. (They are quite cheap and will make to order)
http://www.telford-group.com make cylindrical thermal stores and storage
vessels
http://www.chelmerheating.co.uk (make cylindrical thermal stores)
http://www.rcmgroup.co.uk/




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On Fri, 25 Feb 2005 08:29:03 +0000, pauliepie wrote:


So if you have a standard airing cupboard with a 36x18 cylinder and a 30
gal cold water storage tank above it and the shower head on the opposite
wall in the bathroom mounted the same height as the tank...It is best to
move the tank in the loft!!!!

What if there is no room to put a tank in the loft, there will be 1m
above the taps but not above the shower head?

I guess its the same for a heating header tank, does this have to be a
certain height above the top radiator/pipework.

Is there a rule to say that the htg hdr tank has to be higher than the
cold water tank or vice versa?

That is if you have a loft...
The htg hdr tank can be above or below or on a level with the cold storage
cistern. However see my SealedCH FAQ below.

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

Thanks

I just always thought that yes with the cold water storage tank, the higher the tank is above the highest tap/shower the better the cold water pressure is coming out the taps/shower, but I cant get my head round the pressure from a vented hot water cylinder.
So is it right a cylinder can be fitted either on the ground floor, first floor or a loft in a 3 bedroom semi detatched house just as long as the mcw tank is above the highest tap in the house!
If the cylinder was on the ground floor with the tank in the loft would the hot water outlet be better on a first floor bathroom?
look forward to any replies
thanks

"pauliepie" wrote in message
...

Thanks

I just always thought that yes with the cold water storage tank, the
higher the tank is above the highest tap/shower the better the cold
water pressure is coming out the taps/shower, but I cant get my head
round the pressure from a vented hot water cylinder.
So is it right a cylinder can be fitted either on the ground floor,
first floor or a loft in a 3 bedroom semi detatched house just as long
as the mcw tank is above the highest tap in the house!
If the cylinder was on the ground floor with the tank in the loft would
the hot water outlet be better on a first floor bathroom?
look forward to any replies
thanks

As far as the cyclinder alone is concerned it matters not where it is. The
static pressure at a tap is only determined by the vertical distance between
the surface of the water in the header tank in the loft and the tap.

Is one looks at flow and pipes as wel, it's slightly different. If the hot
tank is downstairs, there is a pipe running down to the hot tank and then
back up to the bathroom. The pressure available in the bathroom (with no
flow) is the same wherever the tank is but, if the tank is downstairs, it
will have to drive water through a longer pipe run, which will introduce a
higher pressure drop from beginning to end, than would be the case if the
hot tank was upstairs. This will result in slightly poorer flow (depending
on pipe bore, length, bends etc).

The taps downstairs will be less affected by the position of the hot tank as
their static pressure will be higher and the difference in pipe runs should
be less.

On balance, therefore, the hot tank is better upstairs, but only because of
minimizing the pipe runs to the lower pressure taps.


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

"pauliepie" wrote in message
...

Thanks

I just always thought that yes with
the cold water storage tank, the
higher the tank is above the highest
tap/shower the better the cold
water pressure is coming out the
taps/shower,

yep.

but I cant get my head round the pressure
from a vented hot water cylinder.
So is it right a cylinder can be fitted either
on the ground floor, first floor or a loft in
a 3 bedroom semi detatched house just as long
as the mcw tank is above the highest tap in the house!

Yep, and above the cylidner. The tank must be the highest point.

If the cylinder was on the ground floor
with the tank in the loft would
the hot water outlet be better on
a first floor bathroom?

Doesn't make any difference. It is best to have the cylinder near the most
used taps to avoid long dead-leg hot water draw-offs; lots of cold before
hot comes through. You could have a secondary DHW pumped loop, that pumps
hot water to each tap for instant hot water at the tap.

In ye olden dayes, a solid fuel boiler in the kitchen heated a cylinder, on
the first floor by gravity circulation. The cold tank was conveniently in
the loft. Amazingly this setup is still being used when all is pressurised
or fully pumped. Installers will fit boilers in kitchen, which is pain in
most circumstances, and a cylinder on the first floor, when all the loft is
there to store both and liberate much needed cupboard space in tiny British
homes. An airing cupboard can easily be created by running the boilers flow
and return pipes around the cupboard or by using a small radiator on the
back wall.




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