Reza is thinking along the right lines and he is discovering the tank size dilemma. In high rise situations where the building code requires a tank it is the mercantile operations that are often going on in that ground floor that may be driving the tank size. There is no example in the code I know of that says to use the nominal numbers as stated in the post. The actual language as I recall implies the tank size to be based upon the hydraulically calculated demand where the calculation method is not qualified to be anything other than how 13 requires a sprinkler demand calculation to be done. That calculation would reflect whatever the flow overage is for the remote area.
Allan Seidel St. Louis, MO On Aug 14, 2013, at 9:50 AM, Ron Greenman <[email protected]> wrote: > You're over thinking this Reza. The design area(s) (not always the "remote > area") is the target in the calculation model. Everything is keyed to that. > The tank will be sized according to 1. the density, 2. times the square > footage in the design area, and 3. the duration. So in the case of light > hazard Q=(0.1)(900+ to 1500+)(60), or adjust for metrics). That's what you > need to CALCULATE to meet NFPA requirements. It's that simple. The rest of > the process is just seeing if you have adequate pressure to meet that goal. > Now there's a certain soundness top your perceived problem, and your > solution, and Richard's, seem like a rationale way to solve said problem. > I'm just not convinced there is a problem that requires a difficult > solution in a sprinkler system, particularly for six stories. Now a water > spray system is a different story altogether. > > > On Tue, Aug 13, 2013 at 11:02 PM, Reza Esmaeili > <[email protected]>wrote: > >> Thanks for comments >> But this is my calculation: >> Occupancy: 6-story light hazard building, with required density of 0.1 >> gpm/ft2 and area of sprinkler operation 200ft2 and a pump is 300Gpm/70psi >> located in basement as well as water tank. >> Required flow rate = 0.1 gpm/ft2 x 200 ft2 = 20 Gpm >> - Scenario1: I use different K factors for each floor to limit the flow >> rate around my required, I use K=2.8 for 1st floor, K=4.2 for 2nd floor >> .... K=8 for 6th floor. In this way the flow rate will approximately vary >> from 21.7Gpm to 29.7Gpm. I calculated 7 active QR sprinklers, so the >> required flow rate for sprinklers is 7 x 29.7 = 208Gpm + 100Gmp hose stream >> total required flow rate = 308Gpm. >> - Scenario2: If I use the same sprinklers with K=8, then at the 1st floor >> the pressure is 60psi. I calculated 7 active QR sprinklers, so the required >> flow rate for sprinklers is 7 x 62 = 434Gpm + 100Gmp hose stream total >> required flow rate = 534Gpm. >> >> - Scenario3: If I use the same sprinklers with K=8, but I reduce the pipe >> sizes of mains on the lower floors in order to increase pressure drop >> through the piping, but is it really possible to drop 30 psi with reducing >> the pipe sizes? Won't make other problems such as high velocity, high >> temperature, etc? >> >> Which Scenario do you like the best to reduce the size of pump and water >> tank? What is the problem with Scenario 1? >> Regards, >> Reza >> www.saeian.ir >> >> >> >> >> >> >> >> ________________________________ >> From: Ron Greenman <[email protected]> >> To: [email protected] >> Sent: Tuesday, August 13, 2013 11:14 PM >> Subject: Re: Different K factor in each floor practical? >> >> >> remember that pressure is your friend. Not having enough pressure is >> usually the problem. >> >> >> On Tue, Aug 13, 2013 at 1:09 PM, Eric Tysinger <[email protected]> >> wrote: >> >>> Also to add, given a 6-story building with a basement you should be >>> looking at about 70ft of elevation difference between the basement and >> the >>> roof. If a pressure reducing valve was used and you limited the pressure >> to >>> 165psi at the basement level you would should still have at least 125-135 >>> psi available at the roof. >>> >>> Eric Tysinger CET >>> NICET III - 108988 >>> Project Manager - Fort Myers Branch >>> Wayne Automatic Fire Sprinklers, Inc. >>> 4683 Laredo Ave. >>> Fort Myers, Florida 33905 >>> p: (239)433-3030 x1240 f: (239)433-3263 >>> C: (239)633-9703 >>> >>> For Fire Alarm Service and Monitoring questions contact us at: >>> [email protected] >>> >>> "Ask us how we can eliminate your Fire Alarm phone line bills" >>> "Ask us about CCTV, Access Control and Security" >>> >>> Thank you, and have a great day ! >>> >>> >>> >>> >>> -----Original Message----- >>> From: [email protected] [mailto: >>> [email protected]] On Behalf Of Eric >> Tysinger >>> Sent: Tuesday, August 13, 2013 4:06 PM >>> To: [email protected] >>> Subject: RE: Different K factor in each floor practical? >>> >>> Assuming that you do not exceed the psi rating of the components >>> (typically 175psi) on any given floor, why worry about the pressure at >> each >>> floor? If you do exceed 175psi, the use of a pressure reducing valve at >> the >>> ground level would be a better choice for controlling your pressures. >>> Changing the k-factors would only limit your starting head pressures, the >>> pressure available on each floor would still remain the same. >>> >>> Eric Tysinger CET >>> NICET III - 108988 >>> Project Manager - Fort Myers Branch >>> Wayne Automatic Fire Sprinklers, Inc. >>> 4683 Laredo Ave. >>> Fort Myers, Florida 33905 >>> p: (239)433-3030 x1240 f: (239)433-3263 >>> C: (239)633-9703 >>> >>> For Fire Alarm Service and Monitoring questions contact us at: >>> [email protected] >>> >>> "Ask us how we can eliminate your Fire Alarm phone line bills" >>> "Ask us about CCTV, Access Control and Security" >>> >>> Thank you, and have a great day ! >>> >>> >>> >>> -----Original Message----- >>> From: [email protected] [mailto: >>> [email protected]] On Behalf Of Reza >> Esmaeili >>> Sent: Tuesday, August 13, 2013 3:34 PM >>> To: [email protected] >>> Subject: Different K factor in each floor practical? >>> >>> Hi! >>> For a 6 floor business office building considered as light hazard >>> occupancy, and the minimum sprinkler discharge density 0.1 gpm/ft2, that >>> the fire pump is located in the basement, in order to adjust flow rate of >>> sprinklers not to be very high at each floor, what strategy is usually >>> considered? Is it common to use different K factor sprinklers in each >>> floor? like the below: >>> Lets say the pump is 30Gpm at 70Psi and consider the below: >>> - Pressure at 1st floor= 60 psi ---- I choose a sprinkler with K=2.8 to >>> have Q=21.7Gpm >>> - Pressure at 2nd floor= 50 psi ---- I choose a sprinkler with K=4.2 to >>> have Q=29.7Gpm >>> - Pressure at 3rd floor= 40 psi ---- I choose a sprinkler with K=4.2 to >>> have Q=26.7Gpm >>> - Pressure at 4th floor= 30 psi ---- I choose a sprinkler with K=4.2 to >>> have Q=23Gpm >>> - Pressure at 5th floor= 20 psi ---- I choose a sprinkler with K=5.6 to >>> have Q=25Gpm >>> - Pressure at 6th floor= 10 psi ---- I choose a sprinkler with K=8 to >> have >>> Q=25.3Gpm >>> >>> The above numbers are theoretical, I just would like to know if it is >>> common to change the K factor at each floor to adjust flow rate? >>> Or may be a pressure regulated valve is better to use at each floor >>> instead of different K factor? >>> >>> Ps. I have considered to use quick response sprinklers. >>> >>> Thanks! >>> Reza >>> www.sarian.ir >>> >>> >>> >>> >>> >>> >>> >>> >>> ________________________________ >>> From: "[email protected]" <[email protected]> >>> To: [email protected] >>> Sent: Tuesday, August 13, 2013 5:24 AM >>> Subject: Re: Sleep on it! >>> >>> >>> Do they stock those foam "dorm" quality mattresses? How many and how >>> stored? >>> >>> I think a lot of places don't. If they do, they ignite easy, and burn >> fast >>> and hot. Burn a single one on edge. The fire is essentially over in a >>> minute, with just a small residual flame from remnant puddle. >>> >>> Temporarily solidified petrochemicals. >>> >>> bv >>> >>> ----- Original Message ----- >>> From: "Charles Thurston" <[email protected]> >>> To: "Vince Sabolik" <[email protected]> >>> Sent: Monday, August 12, 2013 3:07:02 PM >>> Subject: Re: Sleep on it! >>> >>> Hello Vince, >>> >>> Just did one a few months back in a strip center. I will try to remember >>> when I get to the office tomorrow and see what it was. >>> >>> Monday, August 12, 2013, 5:58:24 PM, you wrote: >>> >>>> Hey forum -- >>> >>>> Has anyone done a design for a small retail mattress store? >>> >>>> Would Class III, Group A really apply? Not really storage... >>> >>>> Thanks! >>> >>>> Vince Sabolik, West Tech Fire Protection, Inc. >>>> 11351 Pearl Road / Strongsville, Ohio 44136 440 >>>> 238-4800 Fax 440 238-4876 >>>> ____________________________________________________________________ >>> >>> >>>> _______________________________________________ >>>> Sprinklerforum mailing list >>>> [email protected] >>>> >>> >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>> >>> >>> >>> -- >>> Best regards, >>> Charles mailto:[email protected] >>> >>> _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> >>> >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>> _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> >>> >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>> _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> >>> >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>> >>> _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> >>> >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>> >>> _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> >>> >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >>> >> >> >> >> -- >> Ron Greenman >> Instructor >> Fire Protection Engineering Technology >> Bates Technical College >> 1101 So. Yakima Ave. >> Tacoma, WA 98405 >> >> [email protected] >> >> http://www.bates.ctc.edu/fireprotection/ >> >> 253.680.7346 >> 253.576.9700 (cell) >> >> Member: >> ASEE, SFPE, ASCET, NFPA, AFSA, NFSA, AFAA, NIBS, WSAFM, WFC, WFSC >> >> They are happy men whose natures sort with their vocations. -Francis Bacon, >> essayist, philosopher, and statesman (1561-1626) >> _______________________________________________ >> Sprinklerforum mailing list >> [email protected] >> >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >> _______________________________________________ >> Sprinklerforum mailing list >> [email protected] >> >> http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org >> > > > > -- > Ron Greenman > Instructor > Fire Protection Engineering Technology > Bates Technical College > 1101 So. Yakima Ave. > Tacoma, WA 98405 > > [email protected] > > http://www.bates.ctc.edu/fireprotection/ > > 253.680.7346 > 253.576.9700 (cell) > > Member: > ASEE, SFPE, ASCET, NFPA, AFSA, NFSA, AFAA, NIBS, WSAFM, WFC, WFSC > > They are happy men whose natures sort with their vocations. -Francis Bacon, > essayist, philosopher, and statesman (1561-1626) > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
