Hello,
I am raising my cold water tank to increase the pressure (a bit) of my shower. The tank is about 3 meters horizontally, 1.5 meters vertically, from the hot water tank. Is it best to route the pipe from the cold water tank diagonally down on a gradual angle, or vertically down to the joists, then a horizontal run?
Thanks for any info,
Tony Lennard
It will make no difference at all to the flow but it is normal to run pipework vertical or horizontal,when rasing your tank it is the head of pressure above your shower head that is important 1m from the bottom of the cold tank to the height of the shower spray will give good pressure.to balance the system run a cold 22 pipe from cold tank to shower and same from hot.
The waterflow doesn't care. The extra length is trivial. So just route it however is most sensible to fit it in.
I'd go for the diagonal. And use a pipe bender rather than elbows. The less resistance in the pipe run the better the flow will be.
IIRC raising the tank by 10 metres adds only 1 bar pressure.
Dave
| Hello, |=20 | I am raising my cold water tank to increase the pressure (a bit) of my | shower. The tank is about 3 meters horizontally, 1.5 meters vertically, | from the hot water tank. Is it best to route the pipe from the cold | water tank diagonally down on a gradual angle, or vertically down to | the joists, then a horizontal run?
Horizontal runs are only a Bad Thing for sewage, soil, drain, waste pipes and the like which run partially empty, but not for pipes which run full with some pressure behind them as in this case. Soil pipes etc must have some fall so that they self empty when nothing is flowing down them.=20
--=20 Dave Fawthrop Sick of Premium SMS scams, SMS marketing, Direct marketing phone calls, Silent phone calls?=20 Register with
| Hello, | | I am raising my cold water tank to increase the pressure (a bit) of my | shower. The tank is about 3 meters horizontally, 1.5 meters vertically, | from the hot water tank. Is it best to route the pipe from the cold | water tank diagonally down on a gradual angle, or vertically down to | the joists, then a horizontal run?
Horizontal runs are only a Bad Thing for sewage, soil, drain, waste pipes and the like which run partially empty, but not for pipes which run full with some pressure behind them as in this case. Soil pipes etc must have some fall so that they self empty when nothing is flowing down them.
I can never understand why "head of water" is defined as from the "bottom" of the cold water tank and not the "top" of the waterline at the moment.
I raised my cold tank where the waterline was about 3 feet above the shower head to a new position where the water line was about six feet above the shower head and got a considerable flow improvement.
Could someone please define "head" for me please ? ( in this context !)
Nick
Make sure your hot water tank can cope with the extra water pressure from your raised cold water tank. They are only made from thin copper and come in different grades that can withstand different pressures.
Shame to have a split tank incident.
Please adjust your newsreader settings to insert quote characters in front of quoted text. I have done it by hand above. Without this one has no idea who said what :-(
The definitions define head assuming that the tank is *empty* classic arse covering :-( Reality is different, but the manufacturers are sh*t scared of complaints :-(
--=20 Dave Fawthrop Sick of Premium SMS scams, SMS marketing, Direct marketing phone calls, Silent phone calls?=20 Register with
I don't agree - horizontal runs on low pressure pipework are often the cause of airlocks on initial fill, and running things at right angles suggests using elbows. This (poor flow) is the cause of low pressure showers often being so disappointing - and changing temperature if you alter the height of the head. Careful design can help minimise this. I used 28 mm for the feeds as far as my bathroom and get an excellent shower with only about 3 metres head.
To see how a low pressure system should be designed look no further than custom and practice with drains - you avoid horizontal runs at all costs.
I say the principle is the same with low pressure water. And this theory is born out in (my) practice. It costs no more to take care with low pressure runs - except perhaps in time - and certainly can do no harm.
What a load of bollocks. ;-)
ONLY 1bar!!! That is 14.5 psi.
Is it possible to bend the 22mm. pipe rather than fit elbows? This would make a very marginal difference. It is the 'head' of water that matters. This is 0.434 psi per vertical foot. You can work this backwards from the density of water being 1gram per cubic centimetre.
Chris.
It is to ensure adequete performance when the tank is nearing empty. You don't want your shower to fail when there is still water in the tank.
Christian.
A cylinder that can't cope with 1.5m (0.15 bar) would have to be made from rice paper.
Christian.
Density of fresh water is 1.0 gram per cubic centimetre.
There are 30.48 centimetres in one foot. So... 30.48 x 30.48 x 30.48 = 28316.846592 grams per cubic foot.
There are 453.6 grams in one pound.
Therefore 28316.84 divided by 453.6 = 62.4 lbs per cubic foot. That is the weight of water per cubic foot.
Now divide 62.4 by (12 x 12 x 12) or 1728 to get pounds per cubic inch. That gives... 0.03611 pounds per cubic inch. Multiply this by 12 to get pounds per square inch.
0.03611 x 12 = 0.43333 psi per footThis must be per VERTICAL foot and NOT diagonal or any slope angle.
Chris.
It's not from the bottom of the tank, it's from where the pipe leaves the tank.
Yes with a good quality pipe bender like a Record. Cheaper ones may struggle.
| In article , | wrote: | > > IIRC raising the tank by 10 metres adds only 1 bar pressure. | > >
| > > Dave |=20 | > ONLY 1bar!!! That is 14.5 psi. |=20 | > Is it possible to bend the 22mm. pipe rather than fit elbows?=20 |=20 | Yes with a good quality pipe bender like a Record. Cheaper ones may | struggle.
22mm Bending springs also work, but require a modicum of skill and strength.--=20 Dave Fawthrop Sick of Premium SMS scams, SMS marketing, Direct marketing phone calls, Silent phone calls?=20 Register with
To avoid airlocks the phrase "continually rising" springs to mind.
Also, someone else here noted that a gate valve installed in a vertical run won't gather silt, but it might if fitted horizontally.
Since it's only cold water (and I appreciate this may not be practical) I would be tempted to up the pipework to 28mm to give extra "oomph" when the full draw-off from the hot tank occurs. I'm opening myself to ridicule here, but it's Christmas...
Mungo :-)
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