low water pressure

[moideen]

I have 3 floor building. There is not enough water pressure in taps and bath rooms. the existing 2 set booster pump is GRUNDFOS CR 20-02. Water flow is 92 gallon and 72ft head. the system vet old, I wand upgrade the system with higher capacity. I got proposal with LOWARA pump, with same flow rate and 144 feet head. MODEL SV-22 04. What you think, does it work and solve the problem? Pipe size 2inch ppr.

thanks
moideen

 

[bimr]

It takes more than just a few lines on here to explain how to design such a system. Suggest you take the time to review the concepts in the paper.

 

[cvg]

from the few details I have seen your system is under-designed on all counts. according to the fixture count, your proposed flow rate is way too low. The pipe size is too small for the recommended peak flow. your proposed pump flow rate is too low and TDH is marginal or inadequate assuming your small pipes. assuming that your existing pump runs off the end of the curve most of the time, I am surprised you can get any flow at all up to the third floor. I would think your proposed new pump will not solve the problem

 

[bimr]

Here is an automated spreadsheet:

 

[moideen]

please find the calculated value attached,162 gpm required.there is already two set pump,it can be divide in to 82 gpm each with new system. but the pipe size is 2" discharge, then 7.8f/s velocity and 11.7 ft head loss/100ft. please check the values are correct.i forget to say some stories about the building.the new hoter group take the building for ther staff accommodation. i dont have have any previous condition about the building. the new group increased the water demand by fixing additional sinks...etc.the fixture details are prepared by counting manually.

 

[moideen]

find the drawing of booster pump system

 

[bimr]

Your work effort looks much better.

The pipe velocity is normally designed to maintain a velocity of 6 ft head loss/ 100 ft to minimize piping noise.

Note that the spreadsheet values are conservative, and the water use will never exceed those values in the spreadsheet. I see that you are in the Middle East. There is more water usage here in the States than the rest of the world and the spreadsheet reflects it.

The drawing is hard to read, it would be easier if you printed it in gray scale.

 

[pumpingtips]

QUESTION. Do you have good flow and pressure on the ground floor without the pump on. Provide us with an idea of that first. See you. Pumpingtips