Water pump capacity

[Kenneth199]

If i have a closed water circuit in a Building with 5 floors.
Would it require the same water pump capacity if the water pump was placed on the 5. floor Vs 1. floor?

[Brian_UK]

Shouldn't make any difference.

The pressurisation unit pressure settings will be dependant on its location.

[Segei]

You need pump with greater head.

[Brian_UK]

You need pump with greater head.
Please explain.

[Segei]

Every centrifugal pump has nominal head and capacity. To provide required capacity for 5th floor, pump should have greater head. Usually, head can be increased by choosing two stages pump. Assume that the lift is 15 meters. It means that nominal head of the pump should be 1.5 bars greater than nominal head of the pump for the first floor.

[Goober]

Every centrifugal pump has nominal head and capacity. To provide required capacity for 5th floor, pump should have greater head. Usually, head can be increased by choosing two stages pump. Assume that the lift is 15 meters. It means that nominal head of the pump should be 1.5 bars greater than nominal head of the pump for the first floor.

But what about the weight/pressure of the returning water? I could be wrong, but what you're describing is pumping water to height with no return path?

[NH3LVR]

It is true that the return will negate the head required to reach a height in a system.
However you have to get liquid up to a higher point before this works. (Over the hump, so to speak)
And should you have air or the system is stopped you may not be able to get it going again.

[Segei]

You are right. I mentioned about open loop system. For closed loop I would be concerned about cavitation on suction side. Pump located on first floor will not have cavitation.