Water Pressure Calculator for Dubai and the UAE

In a gravity system, pressure comes entirely from height. Water in a tank higher up pushes down on everything below it.

The rule is simple and worth remembering: ten metres of height gives about one bar of pressure. So a tank six metres above a tap gives about 0.6 bar before anything is lost.

That is why a top floor flat in a building with a roof tank often has weak showers. There is barely any height between the tank and the tap, so there is barely any pressure.

It is also why the ground floor of the same building has strong pressure, sometimes too strong.

A pump adds pressure directly, which is why a booster pump is the answer where height cannot be.

Rough guide to how the number translates into a shower.

This is the single most common confusion in plumbing, and it sends people to the wrong solution.

Pressure is how hard the water pushes. Flow is how much of it arrives. You can have plenty of one and not enough of the other.

A thin pipe with a tall tank above it has good pressure and poor flow. Water comes out fast and hard from a small opening, but two outlets cannot run at once.

A wide pipe with almost no height has good flow and poor pressure. Plenty of water, but it dribbles rather than sprays.

The way to tell them apart is easy. If one tap alone is weak, that is pressure. If one tap alone is fine but everything collapses when a second opens, that is flow, which means pipe size.

Fitting a pump to a flow problem does not fix it. It just pushes the same limited amount of water through the same narrow pipe faster and noisier.

The tank height is what you start with. These are what reduce it before the water reaches you.

A pump is the answer when there is not enough height, and only then.

The clear cases are a top floor flat where the tank sits barely above the ceiling, and a villa where the tank is on the ground rather than the roof.

Before fitting one, rule out the cheap causes. A blocked filter, a half closed valve, a scaled section of pipe or a clogged aerator all look like low pressure and none of them need a pump.

If a pump is the answer, size it properly. Too big is worse than too small here, because an oversized pump cycles on and off constantly, wears out its own switch, and hammers the pipework.

And whatever is fitted needs dry run protection. A pump that runs with an empty tank destroys its own seal in seconds, and that is the most common way pumps die in this country.