Capacitor Bank calculation for a commercial building

Sir i have one drawing of 10 floors building and need to make a quotation for electrical switch gear . i have only details let suppose total number of 13 A switch socket outlet say 600, lights 1000, motors, lifts A.Cs water heaters and rest of the things now i don't know what will be run on the 13A sockets and i have total 500KW load and i am on the design stage help me how can i calculate the capacitor bank for this building????

You can't
You need to know each load to effectively calculate capacitor bank. Everytime you turn something on you change the requirement. You normally only do correction for large individual loads like your chillers. You need to know everything you can about your motors as they are the largest effect on power factor

Good luck

But dear in all over the UAE every one is calculating capacitor bank w.r.t to the load

e.g we have target power factor 0.95
so theta=cos-1(0.95)=18.19
sin(18.19)=0.312
for Three phase Current=KW*1.73
Q=1.73x0.415x(1.73*KW)x0.312

Q=0.387*KW

so we use this formula to find out the capacitor bank details
just tell me is this a right way??

because all over the UAE every one is following this formula and all buildings are designing.

and yes you are right every time when we turn some thing System KVAR requirements change but it is not my problem we have power factor regulators who automatically detect the system KVAR and turn on the steps my problem is only how to calculate KVAR requirement of the system.

You can calculate to a max, situation and use a active system to control.
Strong advice use a central cooling system/chiller with heat recovery.
in that why you can easy control and you do not need water heaters in every appartment.

I am in the UAE temp. for a few days, and it is a shame to see buildings with 100+ aircos.

Dear i am not talking about the cooling system, my problem is every body is calculating capacitor bank rating with the above mention method ..
i just want to know is it right way to calculate capacitor bank ..
let we have total 600KW load i dont know how much we have machines or what about load ..
but i directly multiply 600x0.375 and get 225 KVAR
then we divide it in our steps like my first step would be 5KVAR then seond one would be 10,then 20,25,50 and until i divide my 225KVAR in steps... and make a capacitor bank

Well ASAD if I had to design this, I would assume a worst case power factor of 80% or 0.8
knowing that I am assuming a total load of 500KW then:
S (apparent power) = Power (KW) / PF = 500/.8 = 625 KVa's
now Q(VARS) = SQRT (S^2 - P^2)
so Q=SQRT( 625^2 - 500^2) = 375KVAR's

So the capacitor bank would have a total of 375 KVARs