"These trees burned easily when ignited with a small open flame. Peak heat release rates ranged from about 1.6 MW to 5.2 MW [6]. These heat release rates for dry trees were significantly higher than heat release rates for "Christmas" trees that had been published prior to that time [4,7]."
About 8 years ago I started pestering the P.E.'s here about their fire modeling of required exhaust rates for smoke exhaust systems for atriums from NFPA 92B. They used a 5MW HRR for smoke production. "That's 10 big dry Christmas trees!" they would exclaim. Due to my recent spouting off about the antifreeze final report I thought I had better see for myself. I followed the above reference and sure enough, when they started doing it the HRR for a "Christmas" tree was 500 kW. Of course it really does not matter how many or big trees we imagine, I just like to paint a picture for myself if I can. I think i'll stick to how may 100 watt light bulbs, as if they were 100% efficient, (but not greater than) :) And yes, it is very good to see that residential sprinklers can catch extremely fast fires like they do. brad -----Original Message----- From: Roland Huggins [mailto:[email protected]] Sent: Friday, January 31, 2014 11:15 AM To: [email protected] Subject: Re: Interesting reading-- Res Heads and Christmas Trees Just glanced at the report. According to the abstract, it self extinguishes if the tree is not allowed to dry and and maintains a moisture content in the needles in excess of 100%. How does one exceed 100%? The fire size for a dry tree was 3.2MW to 4.3MW with the needles consumed within 60 seconds. I remember the tree I fired-up in the backyard as a kid went off like gasoline and gone in like 30 seconds. Nonetheless, the fire size for most of us would be much bigger cause the study used a fairly small tree about 6 ft tall. Good to see that a residential sprinkler contained such an aggressive fire. Roland Huggins, PE - VP Engineering American Fire Sprinkler Assn. --- Fire Sprinklers Saves Lives Dallas, TX http://www.firesprinkler.org On Jan 31, 2014, at 7:14 AM, Brad Casterline <[email protected]> wrote: > Impact of a Residential Sprinkler on the > > Heat Release Rate of a Christmas Tree Fire > > > > http://fire.nist.gov/bfrlpubs/fire08/PDF/f08014.pdf > > > > I have learned that where I have imagined Big Dry Christmas Trees they were > more like Medium Size Half Wet Scotch Pines... > > > > > > Brad Casterline, NICET IV > > Fire Protection Division > > > > FSC, Inc. > > P: 913-722-3473 > > [email protected] > > www.fsc-inc.com > > > > Engineering Solutions for the Built Environment > > > > _______________________________________________ > 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
