NTC Brown Book

[jcrawford]

Hi all,

I am thinking of buying the NTC Brown Book. One issue I've had with fire alarms is that NFPA 72 prescribes smoke detector locations based on total, partial, and selective coverage, though the Building Code (NYS) doesn't specify the level of coverage required. Does the Brown Book bridge those kind of gaps between the codes well? Basically, NFPA 72 does a good job of telling me how to achieve different levels of coverage, but doesn't address what types of occupancies need what types of coverage; will NTC Brown Book do that?

-Jen

 

[gadfly56]

Hi all,

I am thinking of buying the NTC Brown Book. One issue I've had with fire alarms is that NFPA 72 prescribes smoke detector locations based on total, partial, and selective coverage, though the Building Code (NYS) doesn't specify the level of coverage required. Does the Brown Book bridge those kind of gaps between the codes well? Basically, NFPA 72 does a good job of telling me how to achieve different levels of coverage, but doesn't address what types of occupancies need what types of coverage; will NTC Brown Book do that?

-Jen

The short answer is "no". Usually when a building code requires automatic detection, it means total coverage. Easy to design. When you are designing a non-required system, you need to figure out what the customer's end game is. They might not even know, so you'll have to walk them through a bunch of questions to firm up what they really want. Maybe they have high value stock in a sprinklered storeroom and they really don't want a fire to get to the point where the sprinklers activate and damage the stock, but they don't want a clean agent system for some reason. A fire alarm system designed to cover that room only with smoke detection would be permissible.

Don't forget that in many cases involving buildings with complete sprinkler coverage that even though the only smoke detector you may need is over the panel, you still have to usually provide notification throughout the building if the sprinkler system activates.

 

[lowvoltageeng]

NTC Brown Book

I bought the Brown book a while ago. #1 it's outdated. #2, it doesn't include what you're looking for. It sounds like what you're looking for is in the IBC. The IBC tells you occupancy types and when smoke detectors are generally required. If you're looking for something more specific than that though your local AHJ can clarify with a phone call. And I'm not trying to bash NTC either. They have online training which I'm sure is more up to date than the brown book. Hope that helps.

 

[ron]

NYS Building code doesn't do a great job in telling you where detection is needed in commercial instances, although most of the time it is some form of partial coverage. http://publicecodes.cyberregs.com/st/ny/st/b200v10/st_ny_st_b200v10_9_sec007.htm

For example, in a high rise, it is mostly in infrastructure rooms.
907.2.12 High-rise buildings.
907.2.12.1 Automatic fire detection. Smoke detectors shall be provided in accordance with this section. Smoke detectors shall be connected to an automatic fire alarm system. The activation of any detector required by this section shall operate the emergency voice/alarm communication system. Smoke detectors shall be located as follows:
1. In each mechanical equipment, electrical, transformer, telephone equipment or similar room which is not provided with sprinkler protection, elevator machine rooms and in elevator lobbies.
2. In the main return air and exhaust air plenum of each air-conditioning system having a capacity greater than 2,000 cubic feet per minute (cfm) (0.94 m³/s). Such detectors shall be located in a serviceable area downstream of the last duct inlet.
3. At each connection to a vertical duct or riser serving two or more stories from a return air duct or plenum of an air-conditioning system. In Group R-1 and R-2 occupancies a listed smoke detector is allowed to be used in each return air riser carrying not more than 5,000 cfm (2.4 m³/s) and serving not more than 10 air inlet openings.