Before purchasing a tap it is important to establish the level
of water pressure you have in your kitchen. The reason for this
is due to many taps requiring high pressure to function
correctly.
If your house is connected to the mains water supply then the
cold water should not be an issue as you will be receiving
pressure from the main water supply which should be around 2
bar.
For most the concern lies with the hot water supply which needs
to be above one bar of pressure. if the hot water cannot reach
one bar then you will need to purchase a low pressure tap, or
alternatively, if that is possible, use a pump to increase
pressure.
Calculating Bar Pressure
Water pressure is generally measured with 3 different units, bar
PSI and head (metres). The general rule of thumb is that 1 metre
of head equates to 0.1 bar or 1.45 psi of pressure.
Calculating your bar pressure requires you to measure the
vertical distance in metres between your storage tank and the
water outlet. Once you have the distance then divide the length
in metres by 10 to get the bar pressure.
The vertical drop pressure is not the only factor calculating
the pressure of hot water from your heating system.
If you have an unvented (pressurised) system where the mains
cold water directly supplies all cold taps and also travels
direct to the hot water cylinder, keeping it at high pressure.
Similarly, if you have a combination boiler it keeps hot water
at high pressure as it heats cold water from the mains as you
need it.
Lastly if you only have a gravity feed system which is aided by
a pump then you will get high pressure of over 1.0 bar.
If your hot water is supplied by a un-pumped gravity fed system
then your hot water is likely to be at low pressure requiring
the use of a low pressure tap.
Taps
Using a mixer tap you need to take a note of both the cold and
hot water pressure. If there is a significant difference in the
pressure of the hot and cold (approx 5:1) then a pressure
reducing valve may need to be fitted to the old supply to
equalise the pressure.
Therefore if the cold water must be supplied at no less then 0.4
bar (or the cold water tank must be located at least 4 metres
vertically above the tap) to avoid having to use a pressure
reducing valve.
Generally speaking, single lever taps require high water
pressure whilst pillar taps and taps with two handles to control
water flow function with low pressure. |
