Terrace tank storage calcs for auditorium and admin building

[parth1981]

Hi all
Iam currently working on a University project in the middle east.
The project contains 2 common basements with around 8 buildings around 5 storeys each for each department,Admin building and auditorium/sports area.I have provided 2 days UG Storage as required by local regulations for all the buildings combined (based on occupancy) . I have to also provide terrace tank with one day storage for each building and my doubts arise here..

1)Auditorium/sports building:
Auditorium capacity - 800 seats
Basketball court - 800 seats
Total Fixture units is 642 and the peak flow is 150gpm
What should be the average flow and hours of storage considering one day storage for terrace tank?
Is hunters curve reliable for auditorium and should I consider any contingency?

2)Admin building4 floors height)
Total Population(staff+technicians+cleaners,visitors etc..) = 300
Going by FU method method total FU is 566 = 140 gpm
i)If i consider average flow 140/2.5 = 56 gpm
then one storage considering 8 hours is around 102Cu.m which is very large
ii)If I directly consider 75 lpcd for 300 people one day storage is only 23 Cu.m
Can i go by second method or any other better ideas

Looking forward for your valuable suggestions

 

[PEDARRIN2]

General guidance on daily use that I have used:

Stadiums, Ball Parks, Etc. 5 gallons per day per seat

Admin Building (Office) 20 gallons per day per employee per 8 hour shift

 

[parth1981]

Hi PEDARRIN2

Thanks for your reply.
On point no.1:
My auditorium and basket ball court are in the same building and should I consider storage for total 1600 seats assuming that events could take place at auditorium and basket ball court at the same time?
If I go by hunters curve what should be the average flow and the storage capacity for one day?(I have read that hunters curve is not reliable for stadiums)

On point no.2:
In the admin building can I go for storage tank considering no of occupants @20gpd instead of fixture unit method because iam getting a large tank of 102 Cu.m by FU method

 

[PEDARRIN2]

Without knowing the operations, I would doubt both would be used at the same time, or at the very least would not have "breaks" at the same time. Is the number of fixtures based on both capacities? That might be indicative.

I would not use Hunter's for stadiums or large auditoriums (likely too low). Sloan Valve had an old document where they gave guidance for flow rates for flush valves for multiple types of facilities. If you had 100 flush valves, you would likely have a maximum peak flow of 225 gpm.

I would not use the FU method to determine volume of use per day - too many variables.

 

[parth1981]

Hi PEDARRIN2
Thanks for your response again.

The number of fixtures are based on both capacities taken from arch. drgs and I too feel both may not have events at the same but thinking of worst case scenario.

My system consists of WC's with flush tanks and if I go by number of occupants,what could be the optimum storage per day

Also for admin building (point2)as mentioned above,can I size storage by occupants instead of FU method which gives me a large capacity

 

[PEDARRIN2]

Use of flush tanks vs. flush valves would not have any bearing on the amount of storage you would need - only the peak flow rate, which is what Hunter's will try to give you.

I would disregard Hunter's and fixture units when trying to figure out storage volume and use the numbers indicated earlier.

1600 occupants would be 32,000 gallons for the Auditorium/BBall Court.

300 occupants would be 6,000 gallons for the Admin Building.

All this being said, the numbers I referenced are based on guidelines used in the US. I don't have any indication of any cultural impact (more or less usage) being in the middle east would have.

 

[parth1981]

Hi
Thanks for your valuable inputs again,but I guess storage for Auditorium/ball court will be 8000 gallons considering 5gpd for 1600 people

 

[PEDARRIN2]

You are right.

I mistakenly used 20 gpd instead of 5 gpd for the Auditorium/Ball Court.

 

[parth1981]

Thanks very much for your valuable suggestions