Thanks Allan! You got the point! My occupancy is 6-story light hazard building, with required density of 0.1 gpm/ft2 over 1500ft2 and area of sprinkler operation 200ft2 and a pump is 300Gpm/70psi located in the basement as well as water tank. I am looking for a way to minimize the size of water tank and pump. I was thinking about adjusting the flow rate of the sprinklers that are near to fire pump which have high flow rate around 40Gpm that I don't really need, I need only 20GPM. So I was thinking about below options: 1- Using smaller K factor sprinklers at 1st, 2nd and 3rd floors which are near to the pump to reduce the flow rate near to the required, but it seems it's against NFPA-13 which restrict the use of small orifice sprinklers. 2- To use smaller pipe size on lower floor, it will save some cost, but I am worry it makes high velocity, turbulence and heat. 3- Installing a pressure reducer valve on main pipe of 1st, 2nd and 3rd floor to reduce the flow rate near to the required flow, I hope these valves are not expensive.
However while my aim is to reduce the size water tank, all of the above options seems to be useless, because sizing water tank is another story.before, I wrongly thought that required water for sprinkler system is calculated based on water usage on most demanding area, that's why I was trying to reduce the sprinkler flow at lower floor! but now Understand this is wrong and I found out that to calculate the amount of water for sprinkler system I should do one of the following: A- Simply multiplying 0.1 x 1500 = 150Gpm B- Calculating water flow for each sprinkler, 0.1 x 200 = 20GPM and total = 7 x 20GPM = 140GPM But is it really correct!? At the 1st floor sprinkler water flow is around 40Gpm and the required water flow for sprinklers is 7x35Gpm=245Gpm, so A and B calculate 150Gpm and 140Gpm which is lower than actual? I know I am not clear enough but I tried to be! Thanks! ________________________________ From: AKS-Gmail-IMAP <[email protected]> To: [email protected] Sent: Tuesday, August 20, 2013 6:45 AM Subject: Re: Different K factor in each floor practical? 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 _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
