sprinkler requirements for large bld ??? 2

[sam74]

Hello, I am currently waiting on a sprinkler company to provide me with their required flows for a 105000 sf justice center. They are also responsible for providing us with the existing flow data so we can design the pipe sizing and hydrant placement from the building wall to the existing lines. We aren't having any luck communicating with the sprinkler company at the moment. Can anyone lead me to the design guidelines they will be using so I can guesstimate what their requirements might be. If it matters this is a Tennessee facility.

 

[rbulsara]

consult or hire some mechanical consultants with fire protection experience. It is a better choice than say a sprinkler co.



Also try posting this in mechanical/fire protection forum

 

[PEDARRIN2]

The sprinkler contractor would be the party to do the hydrant flow test to tell you what is available for flow and pressure, but they might not be the ones to tell you what is required inside the building.

If it is as large of a facility as you are describing, there is probably a mechanical engineering consultant already on board. Talk to the architect or owner and get that information.

 

[TravisMack]

The water demand for the sprinkler system is not dependent on the size of the facility. It is dependent on the hazard classification of the builing. Assuming there is going to be storage limited to 12' in the building, the worst sprinkler demand should be 0.20 gpm / sq ft over the most demanding 1500 sq ft. Include about 20% overage, and you have a sprinkler demand of +/- 360 gallons / minute. You then must include the hose allowance of 250 gpm for ordinary hazard classification. This leads to a total demand of +/- 510 gpm.

If storage exceeds 12', then other factors come into play.

If there isn't any storage to speak of, other than misc files, then you could even reduce the water demand requirements with the use of quick response sprinklers if the ceiling heights are less than 20'.

Please feel free to ask any further questions.

This all comes straight from NFPA 13.

 

[PEDARRIN2]

You also must take into consideration any standpipes in the building. If the building is more than a couple storeys, then standpipes are likely. This would increase your flow requirements to up or exceeding 1000 gpm. This is from NFPA 14.

Again, talk to the mechanical engineering consulting firm doing the inside work. They will tell you what they need for fire suppression inside the building.

 

[TravisMack]

Yeah..forgot to mention the standpipes...the last couple of Justice Centers I did sprinkler layout for did not have standpipes as they are typically 1 or 2 story buildings. In a fully sprinklered building, you should typically only have to go up to 1000 gpm for stanpipes...(500+250+250).

 

[sam74]

Thanks for your responses. Turns out I had a misunderstanding with our mechanical department. They had already provided me with the domestic flow required and they now have provided me with the the necessary fire flow. The sprinkler company forgot to submit a proposal for the pressure test (which is holding everybody up) and I'm assuming they will have calcs for their sprinkler distribution which was where the misunderstanding arose I believe.