You need to calculate the most hydraulically remote 4 heads. This is typically a loaded branch line that supplies a bedroom on the end of the line. For instance (20x20 * (400 sqft) @ .10 gpm = 40 gpm). This end head pressure will act on the rest of the heads on the BL, closets, bathroom, hallway so your total demand on a BL can be upwards of 160 gpm, depending on configuration of the unit. Keep in mind, you can mix K factors in residential occupancies to balance the hydraulics and minimize over discharge.
Jamie Sent from my iPhone On Oct 29, 2010, at 7:24 PM, Carrol Glimstad <[email protected]> wrote: > I'm designing a residential project using res. heads (LFII) and designing to > full NFPA 13. When I calc my four heads using the "design area", I am > wondering > if I can use the room design method to determine my sprinkler demand? For > instance, I have a room that measures 16' X 16', (256 sq. ft.) but the head > is > actually located 10 feet off of the 2 adjacent far walls. If using the flow > rates from the chart I know that I need to flow 20 gpm from that head based > on > my maximum 20' x 20' spacing. But If I'm using the .10 over the "design > area" > can I just use the demand of 25.6 gpm for that head (16' x 16' sq. ft.) > versus > the 40 gpm based on 20' x 20'? I understand then I would then base my system > requirements on the more demanding of the two methods. I can flow all four > heads at a 20 gpm no problem, but the 40 gpm from just one head.....ouch! > I haven't done residential in a looooong time, so thought I'd check for the > heck > of it and I'm pretty sure I'll find instead that I'm full of it! > Thanks in advance! > > Carrol Glimstad > > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email to:[email protected] > (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
