Booster pump necessity in highrise buildings 1

[rudolph15]

I have been performing building audits in a number of existing highrise residential buildings (7 to 12 floors) in southern Ontario. In all cases booster pumps have been installed and are operational. I have come across two cases where the booster pumps have been shut down and to my surprise there is ample water pressure on top floors and there are no operational issues.

Can someone help with understand if booster pumps are really needed in highrise applications and how can buildings operate without any issues on city pressure alone?

thanks in advance

 

[stanier]

It comes down to what the water company can guarantee in terms of pressure and the fire requirements of the local authority. It may be the water pressure varies diurnally or annually.

When there is a fire the pressure may not be sufficient.

“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King

http://waterhammer.hopout.com.au/

 

[bimr]

Municipal water pressures are generally in the range of from 30 to 70 psi.

You need to know the water pressure at the first floor and the number of floor levels to determine if there will be adequate pressure on the top floor. A typical building will have a booster set every 7 -10 floors or so to maintain 30-40 psi on the top floor.

A plumbing engineer would typically design the building plumbing system with pressure zones throughout the building.

The link should clarify the issue.

As an example, given a 50-story building, the 50th floor usually has a governing pressure around 30-40 PSI and each floor height of 12 feet adds 5.2 psito the pressure as you go down in the building from the top.

http://www.plumbingengineer.com/sept_09/code.php

http://www.taco-hvac.com/images/boost.pdf