Wow...just a second....so how big does an obstruction have to be before it will affect the operation? There's only a handful of guys that I would classify knowledgeable enough to speculate such a statement. That's a pretty bold statement to make especially given the number of factors in play including and most importantly ceiling height above the opened door...
Let's step back a minute...we have a 4ft rule that has been around since parchment paper and we have all swallowed the idea that as long as something isn't greater than 48" we are all safe, but at 49" people may die and buildings may burn down. Agree or disagree with this untested rule...it is what it is. Now, unknown to many, we now have some modeling and testing that is currently being worked over in this cycle to introduce guidance for clouds and gaps. However, until such time as that gets worked over and argued about in committee, let's just stick with the 48" rule and leave it at that...anything beyond that is pure beer and peanuts. Let's just say sprinklers are required under the doors and yes, you can omit them. 23.4.4.6.3.1 and 2. Hopefully we will have better info next edition. Steven Scandaliato, SET CFPS 520.971.2322 Cell -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Tony Silva Sent: Monday, October 07, 2013 11:06 AM To: [email protected] Subject: Re: Sprinklers Below Overhead Doors Your question leads me to believe that you think only one head will operate if the door was up. I don't believe the door will act as a heat collector to prevent the head at the ceiling from operating. True, the door when raised will be an obstruction but the door being up or down won't have much of an effect on the operation of the sprinkler heads. So why make a difference in the method of calculation? Tony ----- Original Message ----- From: "Mike Hill" <[email protected]> To: [email protected] Sent: Monday, October 7, 2013 10:32:47 AM Subject: Sprinklers Below Overhead Doors Question: Are sprinklers below overhead doors required to be included in hydraulic calculations? When I first started in the industry, I was told that heads below overhead doors were required to be included in the hydraulic calculations. The reason being, it was a temporary obstruction. The door could be up or down if a fire broke out, unlike a large duct which was a permanent obstruction. I was recently questioned by a FPE as to why I included heads below the door in a hydraulic calculation. I explained my reasoning to him and he accepted it. In his eyes I had proven a more demanding situation than was needed so it didn't affect his stamping the plans. Flash forward a few weeks and to a different project. I now have a much larger operating area and removing these (11) heads from the calculation would help it greatly. I am providing protection for a firehouse expansion on a military base. This calculation is in the apparatus bay. UFC requirements are in effect, ceiling height over 20'-0" and it is sloped enough to require the 30% increase. The majority of the piping being calculated is existing and to remain as is (if at all possible). Using 2007 Edition of NFPA-13 (only one I have handy at the moment). 8.5.5.3.1 Specifically mentions overhead doors need protection below. No problem here. 22.2.2.6.3 Does not mention overhead doors when providing situations where sprinklers can be omitted from hydraulic calculations. The wording in these sections seems to support what my mentors instilled in my soft pliable mind all those years ago. What says the forum? Mike Hill _______________________________________________ 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
