[murad79yameen]

How I can select the pump after I get the flow required and the head
I have a closed loop system chillers in ground level and 35 floors height
Are 4 bars enough to start the system which is the head that I calaculated?
What is system pressure then?
Do I have to add the vertical height also to the total of the pump pressure?
The head doesn't represent pressure of the system is that true?

[caibuadday]

how i can select the pump after i get the flow required and the head
i have a closed loop system chillers in ground level and 35 floors height
are 4 bars enough to start the system which is the head that i calaculated??
what is system pressure then??
do i have to add the vertical height also to the total of the pump pressure?
the head doesn't represnt pressure of the system is that true?

4 bar only get you up to 11 floor(max, assumed each fl is 12 ft H), 1 bar= 14.7 psi(g), to pump water up to 1 ft H you needed 0.433 psig. A 35 story building require min 182 psig
At 182 psig won't be enough because that is only for the vertical lift, you also have pressure loss due to friction loss( piping and associated fittings , your coil and chiller)

[RavenLord]

You 7abeebi .
First of all you have a 35 Floor Building , and what you require is a minimum of 11.5 bar , and several not just one . Always put one on the stand by mode ,

The pump has to be chosen according to both Horizantal and vertical Pipes , Vertical Pipes are important in your calculation ,
If you are in the Gulf use grandfos Grundfos | The full range supplier of pumps and pump solutions